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Comments
Sam.
For sure, before condemning the oil pump or worse, I'd change the oil and filter and see what happens. Maybe there is excessive fuel dilution. All the hoses to the filter are hard lines I believe so that's not the problem.
I am new to the list. I have a 91 300D with 278k. Only recently has it been giving me grief, although minor (water pump). I am having the problem with the hard shifting and top speeds of about 35 at the top of hills. No power on takeoff. If I am on a flat road, I can get to whatever speed I want. I have checked every vacuum line I can find, and I have some suction on all of them when the car is running-even took off the shroud and checked the transmission line. My transmission fluid level is fine. I sprayed canned air through the lines to make sure there were no blockages, and all the connections seem tight. I have no problem with the a/c or the windows, and the cruise control works fine (for what it is worth). Which part should I be looking at for repair /replacement, or should I throw up my hands and go to the local dealership? Please help....
0-60 went from 22 seconds to 16 seconds.
0-30 went from 8 seconds to 6 seconds.
While still a slug, it is an energetic slug.
I would love to replace the turbo on this car with a supercharger. This would eliminate the turbo lag and bring on respectable performance right off the line.
Has anyone done this before? Is there a kit available? Given the simplicity of the turbo system in this car, I see this as being almost plug and play.
Perphaps I've over simplified, but it seems very doable with a very high probability for success.
An Eaton M62 or M90 would be more than adequate for the job.
Sam.
I respectfully think you're barking up the wrong tree. These cars were never built for performance. Durability, reliability, and economy are what they offer. If you want performance try the new Pontiac GTO with the supercharger. I'm not thinking of entering either my 79 300D or 87 300SDL in any performance competitions. They are both dogs and I love pets whether they are the furry kind or diesels.
1. should i expect overheating problems in this tropical climate and hilly terrain? what could i do to prevent that? (i'm a recovering VW addict, and i don't want to go there again).
2. 300D performance w/ biodiesel? is it self aspirated, are there issues with this?
3. considering the shipping costs included in the price ($1000) does this seem like a reasonable price?
4. how can i prevent rust in a salty air environment, if i bought it i'd want to keep it nice, especially considering that all other mercedes diesels on the island are rust buckets?
5. would you classify this generally as a "project car"?
6. what tend to be the AC problems (i know it doesn't work on this) and success with fixing them?
7. do the D models get less gas mileage than the TDs, why? it would seem that the increased performance of the TDs would lead to increased consumption, is that a misunderstanding?
i know this is alot to ask but i don't want to repeat used car mistakes (i ain't rich, but i am earnest and diesel inclined, and i need to get to work on time!) i need some objective friends to help me out. if it seems like a bunch of work i might be forced to buy a subaru.....hmmmmm.
many thanks for any responses!
No overheating problems should occur, no.
2. 300D performance w/ biodiesel? is it self aspirated, are there issues with this?
If you mean pump B100, it should be fine but you MUST replace both your fuel filters after the first tankful of B100 and probably again a few tankfuls after that. B100 is a very good SOLVENT and will clean out any of the crud in your fuel tank. Stock up on fuel filters if you are going to do this switch.
3. considering the shipping costs included in the price ($1000) does this seem like a reasonable price?
Yes, seems reasonable for Hawaii.
4. how can i prevent rust in a salty air environment, if i bought it i'd want to keep it nice, especially considering that all other mercedes diesels on the island are rust buckets?
You can't---it will rust. Don't fight it. It is useless.
5. would you classify this generally as a "project car"?
No but it is very old so you never know. Generally if you don't push them too hard they are pretty reliable cars.
6. what tend to be the AC problems (i know it doesn't work on this) and success with fixing them?
Problems are mostly with the temperature controls and vacuum actuators but even when working perfectly the AC isn't very good on these old Benzes. You might get lucky. First you have to decide if the compressor is seized. If it is seized you got big trouble since debris from the seized compressor has contaminated the entire system. Big job, lots of $$$. If not seized, or just stuck from age, you might get lucky like I did. I bought a used compression, flushed the system, put in a new dryer and charged it and it worked (after a fashion). It's simply not good enough for Hawaii but it's better than nothing.
7. do the D models get less gas mileage than the TDs, why? it would seem that the increased performance of the TDs would lead to increased consumption, is that a misunderstanding?
About the same. You'll get about 20 mpg in Hawaii because there's not much highway to cruise for long distances.
As for performance, they are very slow, so if you go mountain climbing, you must be patient. It'll make it though. 0-60 is about 19-23 seconds.
Feels like a vacuum leak - but it is like looking for the short straw in a haystack.
Any idea where I can get a shop manual - or at least the pages - showing the layout, color code, and maybe where the critical parts are located?
http://www.toadhallbook.com/book.cfm?GI=1&CI=7
or you can buy the three volume set from Mercedes dealerships or just the engine book if you wish.
I don't think vacuum has anything to do with your problem.
Best thing is to change the filters, adjust the valves, and dose the injectors with a strong cleaner or a "purge"...something really toxic that will knock birds out of trees. :P
as for the bio-diesel issue, no i do not mean the B100, i mean any kind vegetable oils: go to the chinese restaurant & get their copious amounts of old oil, filter the oil, and installing a pre-heat pump (to keep the viscosity low), is the method of choice over here (whether or not it's a fad is too early to tell). i know this can work very well in turbodiesels as there are a number of folks over here doing just that, however none of them have such an old non-turbo model. what do you think? please feel free to get technical or theoretical, i'm looking for all sides to the story.
the main reason i would get such a car would be to use vegetable oil in it, so if that seems like a bad route i need to know early on.
by the way, this is a wonderful forum, even if i don't get this benz, i look forward to checking in anyways.
Rudolph Diesel actually wanted his engines to run on vegetable oils, and I think he ran his first demo engine on palm oil.
Also, about a month ago, my A/C was ice cold. Since then, the car has been parked for 2 months in a hot spot, and the A/C no longer is cold, it is just slightly cool. Any connection there that anyone knows?
Many thanks and great forum, I really enjoy reading through it.
The 21:1 compression ratio is not there for power. It's there to ignite the fuel mixture.
A turbo charger adds more air and thus allows for the combustion of more fuel.
At 6000 feet elevation, I have about 11 PSI of air pressure absolute. The turbo adds another 8 PSI. Effectively allowing the combustion of nearly twice the air.
Unfortunately, the turbo does not begin to spool up until about 2400 RPM. Prior to that, the engine is running only on the air available at my altitude (11 PSI). The problem is worsened over an NA engine in that prior to any assistance that the turbo provides, the exhaust obstruction caused by the impeller of the Turbo makes the expulsion of exhaust gasses more difficult. In other words, the turbo helps when it finally starts to make boost, but makes things worse prior to that. So I have the double whammy of having lower pressures caused by high altitude and an exhaust obstruction to boot!
A supercharger is driven off of the crankshaft. It's a positive displacement device which provides IMMEDIATE and CONSISTANT boost in all RPM ranges. No waste gate is necessary, because no over boost condition can ever exist. It is simply a ratio of the displacement of the engine VS the displacement of the supercharger.
I am not proposing an increase in boost at all. I intend to feed the same 8 PSI into the engine, I am just proposing to do it at ALL RPMs. This is not adding any additional strain on the engine.
I think the performance of the 300D when the turbo kicks in is GREAT. I would like to have similar performance when the traffic light changes color at 1000 RPM.
The increase in air temperature caused by the supercharger will also assist in a more complete combustion at lower RPMs as well - reducing emissions and decreasing the objectionable smell of the diesel at low RPMS.
We are talking about a 20 year old design here. There is more than considerable room for improvement - both in emmissions and in performance.
Sam.
Your seals are probably getting dry. You may have a leak. You can easily check the pressure. On most cars with the ambient temperature about 90 degrees and the engine not running, the pressure on both sides of the compressor will be about 90 PSI.
I have replaced ALL of my R12 systems with ENVIROSAFE. It is a very cheap and SUPERIOR alternative to R12. A can of envirosafe will cost between $4.00 and $6.00 depending upon quantity purchased. Better cooling than R12 and safer for the environment.
Please be responsible. If you decide to go to Envirosafe, do the moral thing and have the R12 evacuated by the local AC shop. DO NOT VENT IT INTO THE ATMOSPHERE.
Your R12 will destroy ozone for 160 years before it finally breaks down. For $40 and some shops may do it for free just to get your R12 you can have the peace of mind that you did the right thing.
Anyway, you can add a UV dye / oil to your system to see where the leak is once you have Envirosafe in it. It also smells like pine (where it is derived from) so you will know if you have a leak just by smelling it. In any case, the UV dye will make any leak, easy to find.
Use a quality ester oil when replacing. Envirosafe is compatable with PAG and Ester oils but I like ester oils more.
DO NOT overcharge. Find out how much R12 your system requires first.
6 Oz of Envirosafe for every 16 Oz of R12.
You can also replace R134 with Envirosafe. Do not vent R134 either. It will destroy Ozone for 6 years.
Sam.
I think you'll end up very disappointed in the results. You can't put a pearl necklace on a hog and have it look a whole lot better. Even the 2006 diesels which are light years ahead of the 300D in engineering, are all turbo engines.
But SC has been done, like in Russian tanks I think, but as I recall they switched to turbos, too. Simpler, cheaper in this type of application I think. SC is great for a big V-8 gas engine that wants to do 1/4 miles all day. The V gives a nice fit for the SC placement and a ferocious high rev motor will get the SC spinning quickly.
A friend converted his '79 300D (non-turbo) and is also having very good success.
In my mind, this is a cost issue, as in San Francisco, Biodiesel is still hovering at $3.50/gallon because of the lack of supply and high demand.
I'm going to convert my '77 300D (non-turbo) this weekend.
--j
What would also be interesting is to figure out the cost of doing this, per mile. I guess you'd have to factor in everything you bought for the conversion, and also what you spend to get the veggie oil, filter it, etc. Iread somewhere that someone figured this out to be $1.50 a gallon.
To be fair though, you couldn't really say to someone that running your car is "cheaper" then theirs running on gasoline or B100, unless you factor in your own labor to do this collection/filtration, etc. every week. You have to give value to your labor if you are making an economic argument.
However you don't have to factor in your labor if you are making an ecological argument, that is "doing the right thing".
To understand the actual costs, you need to factor in the filtration system (I use a 5 micron polyester felt sock filter that I found online for $2.36 each, a 5 gallon bucket with a spigot a couple inches from the bottom, and a kitchen sieve). I've filtered 50 gallons of oil through the filters, so that's about $.05/gallon for JUST the filter). I let the containers sit in the sun so they flow easier, but every once in a while, I will heat a batch of oil on the stove, so there is cost there. Then there's the cost of driving to get the oil (wait, that's free after the first trip). The cost of the conversion (this can vary greatly based on how mechanically inclined you are), cost of replacing the on-board veg filter ($ range depends on the filter you install and how well you search on the web). My collection time is minimal as the owner of the restaurant calls me when she has oil and drop by to pick it up in the containers they buy it in.
Then there is the actual labor costs. It took me two solid days to do the conversion. Then it took a bit of tinkering from time to time over the span of a month to get the system running perfectly It would be really hard to quantify those costs and the costs of my labor for the installation.
It also cost me a couple fights with my fiance (who didn't appreciate the long greasy nights under the hood), but those have already been offset by how happy she is with the car (she drives it on a daily basis).
But the major pros of not paying into the coffers of the petroleum companies as much as we used to (still need to buy motor oil and other such products), and the benefits of eliminating the SOx emissions, drastically reducing the particulate emissions and using a renewable fuel with a closed carbon loop are great. It makes me smile every time I drive around and spans a lot of great conversations.
On the ecological side, the only drawback is that there is up to a 5% increase in NOx emissions, but as a by product of high temp combustion, there's not much that can be done about that yet. (I can't wait for an aftermarket reductive catalyst to be available).
I'll keep close tabs on the labor and materials I put into the next conversion and report back.
Thank you.
Sam
Kathleen
There is ALWAYS more power in ANY stock engine. This one is no exception.
Just to clarify however, I have no problem with the power provided from the turbo. I just don't like the fact that the turbo is not available until about 2400 RPM. Prior to this, the engine is naturally aspirated with a massive obstruction in the exhaust stream (the turbo impeller).
A supercharger is a positive displacement device that provides boost at ALL RPMs.
There are some downsides to superchargers (such as cost and belt reliability in very high power applications, but these don't apply here). A supercharger would provide consistent boost at all RPM ranges and is not inconflict with the engine design. It would also remove the impeller obstruction in the exhaust stream.
Increased air/fuel charge temperature would also improve performance during cold mornings.
Sam.
Be sure to observe the polarity on the jumper cables. Red to positive in both cars, black to negative in both cars. If you any questions about which is which, DON'T do it!
Run the engine in the running car at a high idle (1500-2000 rpm) for 5 minutes with the cable connected before cranking the diesel over.
Still...I can't imagine your husband would be upset by this!?? My wife always thinks I'm going to be upset by minor things and I never am.
Sam
I've done a lot of car conversions including a 1990 Miata engine conversion to a 2002 Corvette Z06 engine (LS6). That car actually gets better mileage than it did with the 1.6L engine it had prior.
I've also supercharged and turbocharged several cars. I am currently on a save the earth kick and playing with an electric car conversion so biodiesel sounds interesting.
What kind of impact on performance was there with burning oil for fuel?
Sam
My thought is to add a MAP sensor to the intake manifold, and a tach pickup to the engine. From there a small PIC (With A/D) processor to calculate engine speed and the D/A input would get a MAP reading (0-5V). From there, a PWM signal can be integrated to provide a driving voltage to the regulator. This would be used with a 3D table to build a propane injection profile for all RPM and MAP values.
Has anyone done propane injection with the 300D?
Sam.
The throttle response felt weird to me. It felt like there was almost no response from the engine at all until I pressed the pedal past the 1/4 of it's travel. After that it seemed that the turbo kicked in and the car would move (fairly well I might add). I understand the concept of turbo lag and I've owned underpowered cars before (73' Super Beetle), but it just didn't feel or sound like the engine was doing much of anything until I really pressed down. Sort of as if there were play in the throttle linkage.
It started up immediately and idled fairly well but after I drove it around and later put it in park, it idled rougher than when it was first started. Just rough enough that when sitting in the drivers seat I could see the car shaking.
The car has 141,000 miles on it, the interior is excellent except for a cracked dash pad and some missing strips of wood trim. The body is straight and shiny except for one ding. No rust on the body itself but underneath, where the rear passenger footwell meets the rocker panel, it's rusting through. I'm thinking this would be an easy and inexpensive ($200) cut and weld repair being it's not a cosmetic concern.
He's asking $2,300 for it, which I feel comfortable with for a reliable, attractive daily driver.
Any insights would be greatly appreciated.
No you didn't hurt anything by leaving the key on but you could hurt something by not getting the battery charged up slowly and properly. It's okay to jumpstart the car if you have to do it that way to get it to a charging station.
Now all I have to do is convince my husband that this is a minor thing, right?
Kathleen
As for rough idle, it shouldn't make the car shake, so that's a deficiency. But what it means, who knows without a compression test. You could take your chances and buy it and then adjust the valves, change all the fuel filters and add a very strong injection cleaner. This three step process often does wonders for old diesels.
As for the rust, I personally wouldn't be so casual about it if you haven't had the car on a lift. The rust you see is never all the rust there is....sometimes it is localized but you'd want to check the whole car and especially at any point where the suspension meets the body. If there is rust say where your B pillar meets the floorboards and frame, that's not so minor.
I don't know what part of the country you are in--in some parts, rust is a way of life and buyers aren't too concerned about it---in California, a rusted car is near worthless and difficult to unload.
So keep in mind the rule of thumb: "whatever gets you into a car cheap will haunt you when you try to sell it".
Naturally I would expect all old MB diesels to have needs---this is why you have to be careful what you spend on a used one.
by the way, make SURE you play with the climate control and that everything works (heat/AC) as it should. If they don't work, they can cost lots to fix, and if they don't work at all I'd reconsider buying this car.
I cleaned the injectors using Lubro Moly Diesel Purge, had the valves adjusted, and replaced the motor mounts and she purrs like a kitten. Well not really, but close. The injector cleaner worked so well that I used it on our 300CD too. She really purrs now!
Remember, the transmission was not shifting into higher gears on my 1982 300D turbo, and here's what I did-
I replaced the white transmission vacuum valve that sits on top of the injector pump- I got a used one from ebay- the guy said it was good. Anyway, I think the shhifting is better, but I am still concerned. From 1st. to 2nd- no problem; shhifts smoothly right away. But then it wants to go upto 4500 rpm (maybe even 5000) and gets upto almost 50 mph before it shifts and comes back to 3000 rpm. Then, wants to go back to 4500 before shifting. At 70/ 80 mph, it drives so smooth at 3000 rpm- it is wonderful. If I am driving in traffic and going 40 mph, it does not shift higher.
It seems to me that it is taking awful long to go from 2nd. to 3rd. gear, and I don't recall it hitting 4500 rpm. The engine just sounds different (the high rpm sound), until it shifts back to 3000 and then it sounds fine.
This does not seem right does it?
1) Is there any way of testing whether that transmission vacuum valve is good or not?
2) Would purging the nozzles help?
3) Is there any transmission set points that could be adjusted?
Or, if i take it in, should I be prepared to hear "tranny needs rebuild?"
I am inclined to think there is some adjustment or part that is the issue, because once it shifts, it purrrs smooth! I have replaced both fuel filters.
Anybody else have this problem?
Thanks.
You think a clogged tranny filter may be the culprit?
RE: late shifting -- a transmission service can't hurt anyway--it's hard to say if it would do any good, but it's a pretty easy service on that car.
http://dieselgiant.com/mercedes_diesel_maintenance_tips.htm
I still think a biocide in the tank is a good idea if you are running regular diesel fuel and you have an old fuel tank that you know nothing about.
In fact, when an automatic transmission is rebuilt for abuse and reliablity, the exact opposite is required. In that case, a "shift kit" which increases pressure to shift valves is added.
By shifting more quickly (jerks when shifting) the transmission must dissipate less heat in its clutch packs. The shift to a different gear is over very quicly. A slow shifting (smooth) transmission will subject its clutch packs to significantly longer stress periods where heat builds up in the transmission.
When building my transmission for my 405HP miata (LS6/4L60E), these shift times were reduced to less than half stock times. The result is a very firm shift. The transmission as it is built will handle in excess of 700HP. The shift from 1st to 2nd is so firm that I actually spin the wheels at 45 MPH when the shift takes place.
There are several reasons that are not serious that a smooth shifting transmission will shift a bit harder. One of the most common is that the fluid is burned. Examine the color. If it is bright red, it is fine. If it is more of a brown, it is time to change it. If it is gray, it was time to change it many thousands of miles ago. When the fluid is burned it is no longer lubricating the shifts as well as it used to. The clutch packs bind up more quickly causing the shifts you are talking about. Solution: replace the fluid and it will most likely shift more the way you expect it to.
There are a couple of other less serious reasons that the tranmission will shift a bit abruptly but the bottom line is that in and of itself a harder shift is not that concerning.
Examine the condition of the fluid before walking away. By the way, you must completely purge the transmission of the old fluid. There are several ways of doing this, but the easiest is to have it done by someone who specializes in this. Typically, they T in the cooler lines and continue to drive in fluid until it is clear. This is the only way to remove the old fluid without a disassembly. Replace the filter, replace the fluid.
There are several very high quality fluid options today. I like Redline Ester products. They are engineered molecules that use fewer viscosity enhancers and last longer and lubricate more predictably.
Of much greater concern is if the transmission shifts too slowly or slips. That indicates wear and a transmission that is due for a rebuild.
Sam.