A Mechanic's Life - Tales From Under the Hood

isellhondas

Mr_Shiftright said:

That's funny you mention that. My steering angle sensor code is a temporary resident at each oil service an has been for the last 65,000 miles until turned off each time.

I had my MINI cat go bad but unfortunately nothing in a can could fix it, as it just fell to pieces internally. Were it not for creative thinking, I would have been skunked for $1800 bucks.

I have to say, I hope BMW has upped their quality control for the MINI over the last 10 years, because it has been disgraceful on the early cars.

So....did your "creative thinking" involve a "test pipe"?

Mr_Shiftright

Nope. The car is totally emissions compliant out the tailpipe. I would never run a dirty vehicle.

thecardoc3

stever said:

Your cat's chemistry may have been thirsty for a shot of acetone. But mine may just ignore the fumes. (hm, maybe for the search engines I'd should spell out catalytic).

Or maybe you hit a bump just right driving over to get the codes rechecked.

I'm not so convinced about Techron anymore either. That really gets back to the seat of your pants testing.

http://www.bobistheoilguy.com/forums/ubbthreads.php?ubb=showflat&Number=2504457

Chevron Techron MSDS

javascript:openDataSheet("MSDSDetailPage.aspx?docDataId=283264&docFormat=PDF")

BG 44K MSDS
http://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&cad=rja&uact=8&ved=0CCAQFjAA&url=http://www.petrotech.co.il/PetroTech//userdata/SendFile.asp?DBID=1&LNGID=2&GID=470&ei=fe-wVIyZJofasASL8YGgAg&usg=AFQjCNH3aB-jSB6oiEym9_Si-J0_WrnSbw&sig2=v0lUB7xVdSFwP73X4AXbYA&bvm=bv.83339334,d.cWc

http://www.bobistheoilguy.com/forums/ubbthreads.php?ubb=showflat&Number=1937868

imidazol97

thecardoc3 said:

javascript:openDataSheet("MSDSDetailPage.aspx?docDataId=283264&docFormat=PDF")

Couldn't get that link to work and found this in the BIOG discussion you linkedo--thanks.

https://cglapps.chevron.com/msdspds/MSDSDetailPage.aspx?docDataId=283264&docFormat=PDF

I've used Techron Fuel System cleaner in my cars since BMW started recommending it (Steve Overbeck
talked a lot about it on his Cincy radio car repair show on 550 AM.)

When I'd put it in, within 10-20 miles I'd feel the difference in acceleration. This was in the 80s and 90s.
But now when I use it, I notice little change in my 3800s in the leSabres. I had. I attribute that to improved
gasolines in general and engine/injector designs that minimize the need to cleaning.

I listen to a Detroit 760 car talk on Saturday mornings and they push the BG44 like it's the
greatest thing since sliced bread. They recommend using it something like every 30K miles--
I may be off on that. Of course it has to be done by a shop unless one buys the contraption
needed to connect and inject the stuff at home. I conclude they like BG44 because the
shops get the money. With Techron they can't figure out how to charge the customer for
the customer putting it in himself. :grin

thecardoc3

BG44K is Chevron Techron repackaged. The issues that consumers are starting to encounter especially with direct injection is that the fuel is no longer sprayed onto the back of the intake valves which helps keep them cleaner because the detergents get to work on the valves. Since direct injection delivers the fuel right into the combustion chamber only periodic intake system cleaning tries to address that build up of carbon deposits, hence the need for the induction cleaning systems. That means the performance of such services is in fact a legitimate routine but a lack of education in the public all but criminalizes them for doing it.

roadburner

imidazol97 said:

thecardoc3 said:

javascript:openDataSheet("MSDSDetailPage.aspx?docDataId=283264&docFormat=PDF")

Couldn't get that link to work and found this in the BIOG discussion you linkedo--thanks.

https://cglapps.chevron.com/msdspds/MSDSDetailPage.aspx?docDataId=283264&docFormat=PDF

I've used Techron Fuel System cleaner in my cars since BMW started recommending it (Steve Overbeck
talked a lot about it on his Cincy radio car repair show on 550 AM.)

When I'd put it in, within 10-20 miles I'd feel the difference in acceleration. This was in the 80s and 90s.
But now when I use it, I notice little change in my 3800s in the leSabres. I had. I attribute that to improved
gasolines in general and engine/injector designs that minimize the need to cleaning.

I listen to a Detroit 760 car talk on Saturday mornings and they push the BG44 like it's the
greatest thing since sliced bread. They recommend using it something like every 30K miles--
I may be off on that. Of course it has to be done by a shop unless one buys the contraption
needed to connect and inject the stuff at home. I conclude they like BG44 because the
shops get the money. With Techron they can't figure out how to charge the customer for
the customer putting it in himself. :grin

Techron and BG 44K are both excellent products. And BG 44K is available in a can or bottle.

Having said all that, I'm sure that neither one actually work and you should NEVER use them; take your car to a "professional technician" instead.

Mr_Shiftright

OK, snipers,please...back into your trenches.

Cleaning the induction systems on DI engines using special systems might indeed be legitimate in that you really have to do it at some point (on some cars...yes VW, you can stand up) BUT this brings up the question of the basic design of these systems. I've seen levels of crud in the induction system that damn near boggle the mind. This just isn't right. This isn't good engineering.

roadburner

I've heard lots of horror stories about intake valve deposits in the Mazdaspeed DI turbos, but at 148k mine is running fine WRT fuel economy and performance. I know BMW has brought their walnut blasting machines out of mothballs to address deposits on their DI engines, so I suppose it will be a while before it is all sorted out...

isellhondas

I've never used any kind of an additive and I've NEVER had a clogged injector on any car I've ever owned!

Maybe I'm missing something?

roadburner

You may not have had an injector that was completely clogged, but I have been amazed at the different flow rates of injectors that have been pulled from the same engine. Top Tier fuel has helped a lot and I now only regularly add Techron to my MS3, just to ensure the piezoelectric direct injectors stay pristine(in a DI motor the valves don't see any benefit).

thecardoc3

isellhondas said:

I've never used any kind of an additive and I've NEVER had a clogged injector on any car I've ever owned!

Maybe I'm missing something?

GDI is totally different from fuel injection, there is a lot more going on than just taking the injector and moving from the intake manifold to the combustion chamber. What makes GDI so much more efficient are the different modes of operation that the system runs under. These different modes when used are also a contributing factor to the production of carbon deposits on the intake valves as well as in the cylinder. There are seven modes currently available for the manufacturers to use, but not everyone takes advantage of all of the different ones.

The most common mode of operation, homogenous has the injection pulse occur while the intake valve is open and air is entering the cylinder. This would be similar to how regular fuel injection works today and everyone uses that.

Variable valve timing has now been around for a while, but GDI takes advantage of that strategy to an extreme. Since no fuel is injected into the intake manifold, the engineers can vary the cam timing so that even more cylinder scavenging can take place. Conventional fuel injection would have fuel as well as air being drawn all the way into the exhaust during such extreme scavenging. GDI can simply delay the injection pulse until after the exhaust valve is closed. Most everyone uses this one.

There is another mode, less commonly used called stratified lean that varies the cam timing which allows the cylinder to trap some exhaust gasses. Then with a tumble flap closed in the intake the incoming air is directed across half of the intake valves which traps that incoming air in the middle of the exhaust gasses in the cylinder. Then during compression, just before the spark occurs the fuel is injected right into that fresh air, surrounded by the exhaust gasses. This strategy makes the GDI engine efficiency start to rival the diesel engines but it does so at a cost. The trapping of the exhaust gasses also causes reversion where some of the exhaust gasses travel back into the intake manifold where they can cook any residue from the PCV system operation. This is one of the reasons that the carbon deposits grow on the intake valves. It's a combination of carbon from the exhaust reversion, blow by gasses, microscopic oil droplets etc.

This doesn't mean that the system isn't any good. It simply means they demand more service than what a lot of consumers are used to. All of this technology is one of the reasons for the oil specs that exceed API and ILSAC and what make the articles that tried to discredit the dexos specification inaccurate.

BTW, even Hyundai/Kia requires a fuel additive with every oil change if Top Tier fuel isn't being used on their GDI engines.

Mr_Shiftright

Seems to me, given the habits of the average American driver, that engineering a car that needs MORE service than usual, is not a great idea--even if it had many advantages in efficiency.

stever

Exactamondo.

Not to mention that many of us are "below" average.

Filled up today and didn't even wash the windows, much less check the oil. The tires "looked" fine.

roadburner

Mr_Shiftright said:

Seems to me, given the habits of the average American driver, that engineering a car that needs MORE service than usual, is not a great idea--even if it had many advantages in efficiency.

Well, I wouldn't hesitate to buy another DI Mazda or perhaps an Ecoboost Ford; the rest? I'm not as confident. I guess that's why a Hemi V8 Challenger is sounding better and better...

explorerx4

@thecardoc3, I just added a 3rd Ford 2.0 ecoboost equipped vehicle. This latest is replacing an '02 Explorer that had a 4.6 sohc V8 with 142k miles on it. The only things physically replaced on the engine in 12+ years were the PCV and a serpentine belt pulley.
Any advice on keeping my 3 * 2.0 4 cylinders running well?

thecardoc3

Yea, the first is when it comes to the oil changes. Either use the Motorcraft FS or choose a product off of the shelf that is GM's dexos approved and is both ACEA A1/B1, A5/B5 11. BTW did they switch to the 0W20 yet or is yours still 5W20?

Top tier fuel is a must and use the injection cleaner in the tank with each oil change. Use the Chevron Techron mentioned earlier. Remember BG's 44K IS Techron repackaged at about four times the price. Expect your 30,000 mile services to include an induction cleaning service.

You will likely see a lot of consumers suffer turbo failures, its going to be the same old story. It takes time for them to cool off when you come off the highway so don't just scream into a parking lot and shut it right down. At the least let it idle for a minute or two so that the oil will keep flowing through it and cooling it. Or if you can maybe make sure that the last two to three minutes of your travel try to stay out of boost and that will help cool everything a little quicker.

roadburner

@explorerx4
I don't know if Ford will offer a package for the Escape, but Ford Racing offers emission legal kits that significantly up the power(and preserve the factory warranty) in the Ecoboost motors in the Mustang, Focus ST and Fiesta ST. The kit adds 90 lb-ft of torque at 2,800 rpm in the Focus ST. That's a huge boost; the tune I'm running in my MS3 only averages a 48 lb-ft gain from 3,000-5,000 rpm- but at least it does do away with the ridiculous 155 mph speed limiter.

Mr_Shiftright

no warranty on the race track though.

xwesx

roadburner said:

Does anyone have any experience with a car that threw multiple catalyst efficiency codes that suddenly "cured" itself?

Well, my cars never "suddenly cured themselves," but I haven't replaced a cat yet.

On the first car, fate intervened. I had cat efficiency codes for a couple of years on that one, and they were triggering the CEL more frequently toward the end, so I did a bunch of various research on the subject and finally decided that all of my vehicle's symptoms made it likely that the the best course of action was to replace the oxygen sensors first. I decided to do that once spring rolled around (working outside on the snow pack tends to mean only immediately necessary repairs occur during the winter!). But, at 220,000 miles, psycho driver ran me off the road and destroyed the car, so no worries about the cat at that point!

On the second car, my Escort, it started to throw efficiency codes at about 150,000 miles. I replaced the oxygen sensors as a maintenance item. There were two outcomes: Better fuel economy and I didn't have any more codes thrown for the remaining 12,000-ish miles I owned it. But, I also had some other things going on as well, so I did more work than that at that time. In addition, I replaced plugs, wires, the coil pack (I think it was cracked based on occasional misfires, but I couldn't actually *see* the crack), and engine/tranny mounts, so it was quite an improvement overall. I cannot be certain what part the oxygen sensors played in all that.

xwesx

thecardoc3 said:

GDI is totally different from fuel injection, there is a lot more going on than just taking the injector and moving from the intake manifold to the combustion chamber.[]BTW, even Hyundai/Kia requires a fuel additive with every oil change if Top Tier fuel isn't being used on their GDI engines.

That's great info, 'Doc, thanks!

I find that my Fiesta, with it's 1.6L DI engine, runs like crap on basic 87 octane fuel after only 2-3 tanks. I fill up exclusively at Chevron now (since August '14), and haven't had any issues with it since. Prior to that, it would hesitate terribly during acceleration and my normal fuel system cleaner would "cure" the problem for only a short while. At ~$9/bottle, that was a heck of a lot more expensive (and less consistent) than using the Chevron fuel at an increased cost of approximately $0.15 per gallon.

roadburner

Mr_Shiftright said:

no warranty on the race track though.

That's the main reason I won't consider a new Mustang GT or Fiesta ST- the cars are advertised as being "track ready" but Ford will void the warranty in a heartbeat if you take one to an HPDE. That said based on Automobile Magazine's track experience with their Fiesta ST, I think I know why- the car's rear shocks were blown and three wheels were bent after just one three day HPDE(contrast that with my 140k mile Club Sport, which, after almost 20 years as my HPDE instructor car, is still running its original wheels and shocks/struts).

I've had no problems with warranty coverage from BMW or Mazda. Now, I wouldn't expect any manufacturer to cover a grenaded engine due to a missed shift or to pay for brake pads and rotors- but it is ludicrous for a manufacturer to offer a "Track Package" or to brag how fast their car laps the Nürburgring while simultaneously using the warranty to tacitly admit the car really isn't all that capable...

Mr_Shiftright

Mine does that all the time under certain conditions--I have to be climbing a long, long hill, at high altitude, on a hot day. I'm sure it has something to do with supercharger boost being on for an extended period coupled with air/fuel mixture issues. I just ignore it, and on the downside of the mountain, it goes away after I shut the car off and on a few times while I'm driving around doing errands. If I had to track down intermittent CELs on a German car every time it lit up I'd pull my hair out. (well what's left of it).

roadburner

xwesx said:

thecardoc3 said:

GDI is totally different from fuel injection, there is a lot more going on than just taking the injector and moving from the intake manifold to the combustion chamber.[]BTW, even Hyundai/Kia requires a fuel additive with every oil change if Top Tier fuel isn't being used on their GDI engines.

That's great info, 'Doc, thanks!

I find that my Fiesta, with it's 1.6L DI engine, runs like crap on basic 87 octane fuel after only 2-3 tanks. I fill up exclusively at Chevron now (since August '14), and haven't had any issues with it since. Prior to that, it would hesitate terribly during acceleration and my normal fuel system cleaner would "cure" the problem for only a short while. At ~$9/bottle, that was a heck of a lot more expensive (and less consistent) than using the Chevron fuel at an increased cost of approximately $0.15 per gallon.

That's why I use Top Tier fuel exclusively in my BMWs and Mazda.

roadburner

I whacked a curb pretty good with the RF tire of the Mazdaspeed last week, and brought it to the tire dealer I've used exclusively since they opened a few years back to have it checked. I also asked for an alignment and said that I'd wait on it. The tech came back after 35 minutes or so and asked me what problem I was having with the car and I said none- I just wanted to make certain that I hadn't tweaked something. He then told me everything checked out fine. When I went up to the front desk to pay the answer was "No charge- it didn't need anything."

As an aside, one of the guys that works there has a right hand drive BRIGHT yellow Toyota Altezza- what we know as a Lexus IS. Way cool. Almost all the guys there are car enthusiasts; one guy has a tweaked GTI, another is a Mazda fan who always wants to know if I've made any new modifications to my MS3, and one guy has a Jeep XJ set up for serious rock crawling.

It's really a first-rate operation(part of a locally owned chain) and they have been and will continue to be my default choice for tires and suspension work. Could I get tires a few dollars cheaper somewhere else? Maybe, but I'd rather stick with a shop that does very high quality work and doesn't forget about you after the sale...

imidazol97

roadburner said:

The tech came back after 35 minutes or so and asked me what problem I was having with the car and I said none- I just wanted to make certain that I hadn't tweaked something. He then told me everything checked out fine. When I went up to the front desk to pay the answer was "No charge- it didn't need anything."

That's a keeper. I go to a similar local area chain tire store here. I had my Michelins put on several months back and the chrome plated wheels on my Buick (no remarks about chrome wheels, cloth roofs, and gold emblems please) have deterioration. One was slightly out of round and road force balanced okay. Manager recommended replacing. I finally picked up a reman wheel and took it over when I was in for rotate and balance--no charge to change the tire to the new wheel. I was surprised, because the deterioration of the chrome plate is not their fault. It's due to the winter salt and my not cleaning the wheels every week. I felt they were owed a charge for switching the tires.

That's the way businesses used to be and they earned our allegiance.

explorerx4

@cardoc3, Thanks for the advice. One our vehicles with DI is heading for 35k. I'll have them do the induction cleaning, just in case. I have oil change/tire rotation done every 5k.

qbrozen

I'd want to know exactly what they will do for that service. What really needs attention on a DI engine is cleaning the valves. That is far from a typical service and can be quite costly. And there are different ways of doing it. BMW, for example, performs walnut shell blasting with the head on the car. I've heard of some indy shops removing the head and scrubbing it. I believe most think that just running chemicals through the system is enough, but you can find before and after pics on the net that indicate this is not very effective in many cases.

Since, on a DI engine, you don't have fuel passing over the valves to keep them clean, the buildup that forms can be quite extreme. From what I've read, at least for BMW and VW, you can start to see the effects right around 50k miles. The BMW dealer performed it on mine at about 48k to battle a recurring CEL/limp mode.

thecardoc3

For now there are no solid answers. Some manufacturers are dealing with the potential of carbon deposits by either limiting, or not using any of the GDI modes of operation that are more likely to cause the deposits in the first place. But as most know, not having the fuel dispensed above the intake valves means most of the potential for keeping the valves free of deposits with any level of fuel (top tier) or additives (Techron and others) is still going to be compromised. By periodic induction cleaning before deposits age and really harden, the need to remove the intake and get the walnut shell blaster out is expected to at least be delayed in the majority of cases. There is even the possibility that a major cleaning routine can be eliminated hence the recommendation to do periodic induction cleaning, which introduces the cleaner into the air stream in front of the throttle body. There is a learning curve at play here and nobody can completely predict how this will look when ten years from now as to what was the best choice. No matter how you look at this, GDI means more servicing than previous versions of fuel injection.

BTW Toyota came out with what is possibly a brilliant solution, although a little pricey. They use both port injectors as well as direct injectors and the system switches between the two and even sometimes uses a combination of injection events with both sets of injectors to dispense the fuel charge.

The last we heard, both Ford and GM were talking about licensing this strategy for future versions of their GDI engines, and it is expected that other manufacturers are likely to follow suit depending on whether the trade off for other potential issues caused by the increased complexity is worth it or not.

xwesx

Intriguing! I'm starting to question whether selling my old Escort was the best move. At least it was (relatively) reliable after 160,000 miles! I am not even at 50,000 yet on my Fiesta and the DI engine already gets fussy if I feed it anything but "top tier."

Induction cleaning on the horizon... noted!

roadburner

xwesx said:

Intriguing! I'm starting to question whether selling my old Escort was the best move. At least it was (relatively) reliable after 160,000 miles! I am not even at 50,000 yet on my Fiesta and the DI engine already gets fussy if I feed it anything but "top tier."

Induction cleaning on the horizon... noted!

I'd want to see before and after pictures via borescope if a chemical cleaner was used. Otherwise you are just guessing and/or shooting in the dark(pun intended). My MS3 just hit 149k today with no induction cleaning to date. If I went that route I'd bite the bullet and go with walnut shell blasting; sure it is more expensive, but at least I'd be 100% certain that the valves were clean.

xwesx

I'm not saying I'd take it to a shop for that sort of thing.

But, I am also not convinced that it won't start hesitating again even with the fuel I feed it now. After all, I did have it for about 20,000 miles before it started getting finicky in the first place. For that first 20K, I gave it the "usual" routine of an injector cleaner to the fuel tank every 4K. After a while, though, it just decided that such service was not enough. I noticed that it did clear up for a short while when I did my last bottle, but then started giving me issues only a few tanks later. I gave the Chevron fuel a try, and it was noticeably better on that first tank (and gone after a couple more).

So, while better now, I'm not sure it is able to fully address potential buildup issues.

imidazol97

xwesx said:

I noticed that it did clear up for a short while when I did my last bottle, but then started giving me issues only a few tanks later. I gave the Chevron fuel a try, and it was noticeably better on that first tank (and gone after a couple more).

So, while better now, I'm not sure it is able to fully address potential buildup issues.

A technically savvy car repair shop owner who did a radio talk show on Cincy radio was the first I had heard recommending Techron fuel System Cleaner after BMW had recommended it. His technique was to run the tank down as low as possible so there was little of your lower octane fuel left to dilute the fillup with premium. That way you had mostly premium fuel when you filled it after dumping the Chevron 20 oz bottle in for a 20 gallon tank. Then run two more tanks of only premium. His favorite then was Shell premium or the Chevron premium. If problem persisted use a second dose of Techron FSC after the two intervening fill ups.

stever

From what @thecardoc3 says though, that party may soon be over unless the Toyota fix gets around ("not having the fuel dispensed above the intake valves means most of the potential for keeping the valves free of deposits with any level of fuel (top tier) or additives (Techron and others) is still going to be compromised")

roadburner

Again, it depends on the engine; if the DI engine in my MS3 is suffering from excessive intake valve deposits I haven't seen any evidence of it- the motor idles smooth, both fuel economy and performance are unchanged, and it is not throwing any codes.

stever

And don't forget the Dexos II.5991 version 16, revised edition.

thecardoc3

You can tease about the engine oil requirements but at the end of the day the fact that the specs have been widely ignored is the real reason for threads liken this one:

http://forums.edmunds.com/discussion/12834/gmc/suburban/gmc-yukon-xl-normal-oil-usage#latest

Most people don't know enough about the subject to understand the difference and the jokes can lead to them continuing to fail to service their vehicles correctly.

Mr_Shiftright

Well if the dealer can't get the specs right, that's a pretty grim world we're facing Doc.

imidazol97

thecardoc3 said:

You can tease about the engine oil requirements but at the end of the day the fact that the specs have been widely ignored is the real reason for threads liken this one:
http://forums.edmunds.com/discussion/12834/gmc/suburban/gmc-yukon-xl-normal-oil-usage#latest
Most people don't know enough about the subject to understand the difference and the jokes can lead to them continuing to fail to service their vehicles correctly.

Exactly what oil specification did the owners not follow?

roadburner

stever said:

And don't forget the Dexos II.5991 version 16, revised edition.

THAT"S NOT FUNNY!!!

stever

Too bad I can't afford a Tesla. A little tin of 3-in-1 would probably be all I need.

imidazol97

stever said:

Too bad I can't afford a Tesla. A little tin of 3-in-1 would probably be all I need.

Tesla 3 is "coming soon" and will be sort of $35 K. Should fit all budgets...

thecardoc3

The 6094M and 4718M that were in addition to the API and ILSAC specs. Those are the specs that went into effect back in 2004 that became obsolete when GM changed to the dexos requirement. That specification change made the dexos the required oil for all of their cars back to 2004.

As far as dealers not following the manufacture's specs there is nothing new about that. There is a downside to pricing pressure especially when a lack of education is playing a role in purchasing decisions at any (every?) point in the purchasing chain. That's why articles like this one http://www.edmunds.com/car-care/do-i-have-to-use-the-manufacturers-oil.html worked to mislead not only consumers but shop owners and technicians too.

When you re-read that article you will see Valvoline quoted as not providing a dexos licensed product, today they have an entire line of products that are approved and licensed to meet the specs. http://www.centerforqa.com/gm/dexos1-brands

roadburner

It certainly isn't rocket science; Mobil makes motor oils that meet meet the specs of every one of my cars- and the oils can be obtained easily and at a reasonable expense...

qbrozen

imidazol97 said:

stever said:

Too bad I can't afford a Tesla. A little tin of 3-in-1 would probably be all I need.

Tesla 3 is "coming soon" and will be sort of $35 K. Should fit all budgets...

yeah, we'll see. Wasn't his original projection on the Model S like $50k? Blew that out of the water. I think the Tesla 3 will be closer to $50k in the end.

thecardoc3

roadburner said:

It certainly isn't rocket science; Mobil makes motor oils that meet meet the specs of every one of my cars- and the oils can be obtained easily and at a reasonable expense...

I have one that they do not actually make the oil for. The closest product that they do make states correctly that it is "suitable for" the specification. There is a world of difference between recommended for, suitable for, versus approved for.

roadburner

What car would that be? Mobil 1 0W-40 has BMW LL-01 approval and is backward compatible for all non-///M BMWs(although I do use 15W--50 in the 1975- old habits die hard). The Mazda just takes an SL or higher 5W-30; I run Mobil 1 EP 5W-30 because it is a DI turbo and I figure dexos approval is icing on the cake. The 4.0 inline six in the Jeep gets Mobil 1 10W-30- it isn't picky either.

xwesx

roadburner said:

Again, it depends on the engine; if the DI engine in my MS3 is suffering from excessive intake valve deposits I haven't seen any evidence of it- the motor idles smooth, both fuel economy and performance are unchanged, and it is not throwing any codes.

Yep; I completely agree here. If your engine ran 160K without any issues, clearly my Fiesta's 1.6L DI has fundamental design differences that make it more prone to buildup.

And, it's not necessarily the fuel, either. I run the same fuel (prior to the Fiesta's Chevron switch) in my Forester (EJ25, which is *not* DI), and all my other cars for that matter, and have never had performance issues with them up to and exceeding 200,000 miles (Forester currently has 80K).

thecardoc3

My Mustang.

xwesx

-

thecardoc3

The tip of the iceberg. http://www.doityourself.com/stry/technicianshortage