GM ENGINE KNOCK

minikin

Going back to your original question -- It's not the oil. Pull the Purolator filter and replace it with a Delco PF-59, which has a decent anti-drain back valve. Don't use the PF58; they're cheaper and easier to find, but don't have the right anti-drain back properties. If you can't easily find the PF-59, and they seem to be scarce in some places, use the dura-guard Gold version or a Mobil-1 filter. If you didn't have an issue before your oil change, that should solve the problem.
-- Don

PAman

I spoke to my friend, Steve, this morning on his radio show here in San Antonio.

Any Chevy truck owner that would like to know what I found out, please feel free to e-mail me. I've already forwarded the information to Dr. Phillips (tep) and quadrunner500.

Joe

modvptnl

You having knocking problems with that Duramax diesel????

Don't worry, PitaMan will fix it!!!

plutonious

This GM knocking problem, is it piston slap or something else? I've read a lot about some of the piston slap problems which seems to be caused by too much play between the piston and the cylinder walls of the block/head. Is piston slap distinguishable from true "knocking?"

I know the GM 5.3 has excellent fuel efficiency for its displacement and performance figures, but could the problem possibly be that GM has leaned this engine out too much, and now it has the knocking tendencies? To my knowledge, the GM engines didn't have this problem until they introduced their Vortec engines.

tep

As I alluded to in an earlier post, I have two distinct and separate adventitious engine noises: the cold start-up "knock" or "tap" and a "clatter" which is noticeable at low rpms under slight load (i.e. going uphill).

I'm no engineer or mechanic (though I've been doing my own basic maintenance and service for over 20 years) but that clatter is reminiscent of an overlean condition. In an older carbureted engine that possibility could be readily ruled out with 5 minutes and a screwdriver. I'm not sure how to diagnose it in an engine that probably has more computing power than the mainframes of my childhood!

Just for grins, I tried a tankful of 93 octane to see if it would affect the "clatter"--no discernable difference to my ear.

tep

obyone

You could try changing plugs to the NGK TR55VX platinum or the TR55 and change the gap from the factory setting of 60 to 52-54. Others have experimented with success in the area you're describing.

jlflemmons

Read your owners manual. It will state a different viscosity based on the average temp range the vehicle is operated in. I guarantee you do not want to use 5w30 in Texas during the summer. Houston traffic will break down the light weight oils quickly. 10w30 is the more common year round weight down here. I did get caught in an Arkansas ice storm with 20w50 in a 4 banger Fiero once. Good thing it was a standard as the starter could hardly turn it over.

rayt2

My e-mail address is in my profile if you care to share this info since I did ask the question in the first place.

As for the obnoxious ones, I have a place reserved for them at their local Psychiatric Center. LOL!

Ray T.

modvptnl

....don't you realize you're one of the chosen ones???

After all, you called PitAman "testy" a while back!! We know how sensitive he can be. LMAO!!!!

xyz71

I live in Houston - run 5w30 year round. Never had a problem.

I don't think 5W30 breaks down any faster than 10W30. My engine runs the same temp summer / winter - which is right around 208 degrees. If your engine runs warmer in the summer - just because you are stuck in traffic I would say there is something wrong with your cooling system. (If you are towing a heavy load I would expect a higher temp) I think I will stick with the owners manual -

roger350

Uh, most vehicles will run hotter in rush hour, stop and go traffic. There is nothing wrong with the cooling systems, they just can't defy the laws of nature. As the air temperature rises, the temperature difference between the air and the water in your cooling system decreases. As this delta gets smaller, the heat transfer between the two becomes less efficient. On a 100 degree day, with only the fan to pull air across the radiator, this delta gets pretty small. You've got radiant heat from the concrete road surface, the heat from the exhaust manifolds, etc., all getting trapped in the engine compartment, with very little incoming air to force it out. Things heat up, period. And in Dallas, every vehicle I've ever owned tended to burn a little 5w-30 in the summer, whereas none of them ever burned 10w-30 under the same conditions, regardless of the type of oil used, including synthetics. If your vehicles don't burn 5w-30 in the Houston heat, that's great. But, 10w-30 is what GM recomends for our climate conditions in the summer, if you look at the manual. I wouldn't take my chances on 5w-30 from about May through September around here. Just my $.02 worth.

xyz71

I don't know what the manual says for a 2500 - but the 1500 manual lists 5w30 as the first choice, 10w30 is "ok" if outside temp is not too cold. The oil cap on the 1500 even has "Use 5w30 oil" printed on it. Does the oil cap on the 2500 have any thing printed on it?

I really don't think it makes that much difference - my 5.3 L has almost 30K - I have used one quart of oil in the last 10,000 miles. The way I understand it both oils are 30 weight when they are at operating temp - so the only difference is at start up.
I spend hours every week in Houston traffic - two summers ago the temp was 111 degrees - I was sitting on I-45 - stuck in traffic - A/C on max. My temp gauge never went above 208.

I think Ford even calls for 10w20 oil - but I am sure most owners know better and use 20w50 in the summer. Also a good idea to add 2-3 cans of STP or a quart of 90 weight gear oil if outside temp gets above 80 degrees. (LOL)

minikin

and 2-3 cans of STP. Now there's a really good way to void your warranty!
-- Don

obyone

Haven't seen it on the shelves in years. Remember putting it in my '70 Dodge Swinger.....last time I used it too.

xyz71

I think the "racers edge" had to be taken off the shelf back in the late 70's - early 80's. Seems they were making claims that were - well - just a bunch of lies. As soon as they were limited to the truth they could no longer sucker people into paying $5.00 for a pint of 140 weight oil.

I will admit to putting a can of this [non-permissible content removed] into my 69 Chevy Chevelle SS 396 back when I was a 17 year old punk - thought it would help my 1/4 mile time. Did nothing - I could never get better than 99 MPH in the 1/4. I really wanted to hit that 100 mph mark. I wore out a few clutches and several sets 60 series rear tires - man those were the days.

joe3891

I agree with you on 5W-30 good year round,i made a summer trip out west from the east coast and temps got high as 121 deg F and were mostly 95 to 100+ and going 8500 miles at mostly 70 MPH added no oil.My oil cap has 5W-30 printed on it also.

rayt2

Maybe you could send me this info PAman has found out on 5w30 oils & e-mailed to you, I e-mailed him for it and requested he post on the board but no response, maybe he's outta town and hasn't gotten his mail yet, but curious minds want to know the answer, especially since I asked the question and do own a Silverado.

STP, wow there's a product not talked about for last 20 years, yup I used it once and never again. Did absolutely nothing for performance on my 69 AMX. I had better luck with Marvel Mystery Oil, now how many remember and still use this product ??

Ray T.

eric2001

I believe is still available today. Or maybe not? I still have a metal bottle of it at home. I don't think I would add that in to my gas on a fuel injected vehicle (I remember they recommended adding it to gas to "lube the top end of the motor").

Along the lines of the motor honey. Sure quited-up them noisy lifters, but was only good for trading in a car (never could restart them). LOL
-Eric

rayt2

Marvel Mystery Oil is still available in your better hardware stores. You won't find it at Home Depot or Lowes though, they haven't caught on to this one yet, as soon as they do they'll probably buy the company out so they can control that market too! Their doing their best to put a local longtime hardware store out of business by me, they already bought out the company they used to get all there screws, nuts, bolts & washers from.

Ray T.

txyank1

Furrows that just went out. It is a chain but a very small one compared to Lowes and Home Depot which recently opened in the area. Oh, and to stay on topic, I drive my Sierra there and as of yet no knocks!!

xyz71

Was your AMX the two seater with the 390 CI engine? If you had this car today it would be worth $$$. If I recall correctly this was one fast car.

PAman

I've sent the information to about seven users in here that requested it. If I overlooked anyone, please let me know.

Joe

minikin

good for coating the bearings during a motor build up tho.
-- Don

obyone

Noticed no one mentioned Menards.

ryanbab

menards blows

zr2rando

I use the STP on my 89 Nissan Truck, it has 180k miles on it now. I didn't add STP until about 150k miles and have used it since...it is NOT oil, it is a Viscosity Improver that just keeps the oil from thinning at higher temps like it normally would. I have always changed oil/filter at 3k/3 months and would definitly NOT extend that interval because the STP does break down if pushed too long...It does make a huge difference in that engine (4 cyl). I have not noticed any diff in gas mileage, still gets the same as when it was new. The main reason I am using it is just because of normal high mileage wear, it does make an engine quieter.
As for the GM V8 engine noises, It seems that GM knows they have an issue and are borderline on helping individuals with particularly noisy engines..I would not put anything extra in that engine so that if any long term problem occurred and the customer had been persistent in keeping after the GM dealer/mfg there would be no claim of "customer abuse"...If that engine died at maybe 80k because of the piston problem, I'd hate to hear them say "you're fault dude, you added junk to the oil....
Good luck with the warranty engine replacements, I look forward to seeing GM fix this one.
Rando

obyone

Where do you buy STP? I'd like to get a can for old time sakes....

rayt2

Oby, maybe you can get Richard Petty to autograph it for ya LOL. I used it as minikin says to coat bearings during engine reassembly and once in an old smoker to see if it would stop burning oil, it didn't!

xyz71...I still own that AMX that I bought used off a dealers lot in 71, and it has the rare Big Bad Blue paint option & Go Pak w/390 V8 4spd. Yes it is a two seater, 68,69 & 70 AMX's were all 2 seaters. In 71 American Motors offered the AMX package on the Javelins thru 74. The Javelin was the sister car to the AMX the difference being longer wheel base and a rear bench seat.

Ryan......Menards blows?? I thought you left on your own for a better job.

Oh yea back to the topic....still got that morning wakeup "lifter tap" when cold on start-up for 10-15 seconds, has gotten no better no worse.

Ray T.

ryanbab

i did and after shopping elsewhere i have seen the light

minikin

It's a Viscosity Index Improver. And, besides using it for engine builds, I used to use it in really loose worn out motors. Yours sounds like it qualifies.
However, the idea of pouring a quart and a half of STP along with 20-50 into the crank case of a new motor spec'd for 5W-30 just really, really hurts my head.
Now that I've noticed, I can't find it anywhere, either. I'd really like to get a can or two to go with the rest my collection of automotive antiques; like 4-bbl, '57 Ford intake manifolds.
-- Don

xyz71

Was an attempt at humor - (the clue was the quart of 90 weight gear oil)

Can't you get the same result in an old oil burning engine by using 20w50.

I did know a guy that "winterized" his car by changing the oil and adding 2 cans of STP. The temp got down to -20 overnight and the next morning his car would not even turnover.

zr2rando

STP is still sold these days believe it or not at lots of places...Kmart/Walmart/Joe's parts etc...
It comes in plastic bottles now (and most places have a store brand too!)....I use 10w40 in that Nissan and swap 1/2 qt oil for 1/2 qt of goo...I mean STP...I don't think any more would be such a great idea.
If anyone had any real hangups about using it they could probably swap out 2 qts 10w40 for 2 qts 20w50 just to heavy up the mix I reckon.
I say again though for the GM new V8 issue stay with mfg recommended oil wt just because it looks like it is a design problem at the moment...only do the STP thing on older engines and use short changes intervals (3k/3 mo)...don't screw up a possible GM engine extended warranty on those engines...
Also use the lowest octane gas you can find that does not knock...it creates less carbon residue in the cylinders and gives better gas mileage to boot.
I personally believe in thicker oil/better metal protection over the thinner oil/better mileage idea but I don't get any paychecks from GM either.
I also keep vehicles for a long time, don't believe in leasing them....just depends on what is important to you.
see y'all in the morning
Rando

txyank1

I used it once in a '55 Ford. Rear main seal was shot and oil went right through it. I lived 13 miles from work and stopped every day at the local Gas Station I used to hang out at and topped off with used oil from his oil changes. No, I didn't have this car for too long! The guy I sold it to got caught by the Cops for driving it unlicensed. The leaking oil was getting on the clutch and it slipped so bad he couldn't get away from them!! Ahhh the good ole days.

PAman

All,

A couple of the people I sent this to asked me to put it here in the forum, so here goes:

I spoke to my friend, Steve Gehrlein, on his radio show Saturday morning.

I specifically asked him about the guy who said his engine got noisier when he went from hydrocarbon oil to synthetic oil. Steve's opinion is different from what others seem to be getting from GM so far; that it is caused by the piston skirts. Steve believes the rings are too loose on the pistons, and not the piston skirts making the noise, as GM seems to be saying.

I tend to lean toward Steve's opinion due to his experience in building and racing Chevy small blocks, and the fact that he owns one of the 5.3 engines. If he is right, this would better explain how you can have a noisy engine, yet not have lots of metal in the oil. I'm one of the people who always equated noise with something bad, usually metal-on-metal contact, so I couldn't understand GM saying the noise is no big deal.

He explained that because the rings are too loose, the synthetic oil makes a little more noise because it is designed to flow better, while still coating parts and avoiding a dry start. He says this causes more of the synthetic to flow out of the piston's rings at night while the truck sits for several hours. He said he would recommend going to a 15W40 or 20W50 synthetic for anyone not living in a very cold climate. He said he went to a 20W50 synthetic on his engine and it stopped the noise.

Tom Roper also provided some information he found that seems to be consistent with what Steve told me. Here's the link and a thanks to Tom for providing the information:

http://www.c5registry.com./2k2z06/page5.htm

By the way, I heard the noise first-hand yesterday. When Chevy upped the incentives to $1500 on a 2002 and $3000 on a 2001, I considered trading my 2000 S-10 for a Silverado with a 5.3. One of the trucks I drove also had a 6.0 engine. The noise, while not as loud as a diesel, sounded just like many of you have described. After hearing it, I decided for now to keep my quite 4.3 V-6.

Joe

ryanbab

Mine comes and goes. I havent heard the "knock" in about 2 wks.

4x4man

That article about the rings and piston are addressing two different things. The different rings were to fix an oil consumption problem due to ring flutter, not a knock. The supposed new coated pistons where to address the knock issue.

I don't know how I feel about this ring too loose thing as that to me would indicate a bad wear problem with the rings banging up and down in the groove of the piston....

I don't know I think everybody is guessing at this moment...thankfully my knock has not reappeared in the last few hundred miles.

Bob

quadrunner500

>I don't know I think everybody is guessing at this moment<

I agree.

erikheiker

My 5.3 just hit the 10k mark, and it stills purrs like the day I bought it. I switched to Mobil 1 during my first change at 2887 miles. I have also not noticed any loss of oil between changes. Sweet engine, sweet truck. Between the AutoTrac, 4 wheel disc brakes, Dynamic Brake Proportioning, and ABS, it's like driving in the summer. I start and stop with ease. God I love this truck!

ngpro

Back aroud '89 GM had a similar problem with the 2.2 4 cyl motor. Some we put new redesigned pistons in and others had no repair made because the owners were not bothered by the noise, which was more noticable than the current truck noise. This extracurricular noise ( over and above the normal noise of an engine at work} was caused by clearance problem between the piston skirt and the cylinder wall. no difference in reliability or longevity was noticed between the repaired motors and the ones we left alone

As far as your discussion of additives goes I offer this advice...I use STP (Stops Terrible Pounding) in the summer and Marvel Mystery Oil ( Mechanic In a Can) in the winter. Also!! only put STP in a HOT motor and run that motor for at least 10 mins. to mix the STP well with the oil.

ndahi12

and I will say it again, as long as the knock/clatter is on COLD START-UP and in 2 seconds goes away, then you have nothing to worry about. It is very normal. 60% of the Tundra trucks that I surveyed on Tundra Solutions have it. Admittedly the sample is only 106 truck owners, but it does give you an idea.

If, on the other hand, your engine knocks during normal driving and under load, then you DO have a problem.

eric2001

I am curious. GM offered a "piston soak" to many customers when this first appeared. They claimed it was a carbon build-up on the pistons. Those that reported having it done claimed it worked (for a while anyways), but most said it came back after a while (build-up again?).

Also, a few people have stopped the start-up knock after some injector cleaner and hard running (trailering with high rpms). This seems to point to a carbon build-up theory.

What I am wondering is if Toyota has done anything along these lines? Has anyone brought their Tundra in and gotten an explanation on the knock?

On another forum someone mentioned these issues could be fuel related, not a motor/manufacturer issue...

Still not sure.
-Eric

ryanbab

last time i changed my oil back in sept about 10 seconds after i started the truck up there was a slight knock.

This morning i changed it and there was no knock.

hmmm

ndahi12

Perhaps we need to differentiate the knock/clatter we are talking about. Tundra owners speak of two types of clatter/knock

1. The knock on first COLD start-up in the morning. This happens when the temperature dips really low. I hear three knocks and then it goes away and it never comes back during the day. I only hear it with the door open and sometimes with the hood and the door open. I have not heard it with the door closed and I am inside the truck.

2. The second sound is the clatter that comes from the DOHC valvetrain and injectors. I think this is caused by the lack of oil in the valvetrain after the car sits over night. The truck sounds boomy/clattery and then it goes away.

Toyota has not issued any TSBs about this. Most of those who took their Tundras to the dealer got the usual "It is normal" answer.

I think those who really want their dealers to do something about it must be armed with more than the noise. They need to get an oil analysis done at blackstone labs. If the result shows a higher than normal rate of metal in the oil, then they have EVIDENCE of wear and can force the dealer to do something about it.

Once I get more mileage on my Tundra (currently at 1500) I will do an oil analysis and report back to you guys with the results.

obyone

I'm kinda wondering about them. First, they are located in Indiana. Two things about Indiana. My truck was manufactured there and secondly, well, I won't mention that one. hehe. When I received the test results, the comment section said everything is within normal parameters. I had very high readings in Copper and calcium. When I questioned them about it. They replied,"uhhh, could we get a sample of unused oil since you are the only one we've tested that used Lubriplate". I said sure, but what do I send it in as they state that they will send additional containers with the oil analysis report.......doh!

ryanbab

elaborate on

"secondly, well, I won't mention that one"

seelig

want Dean to spell this one out for?
good luck on this one now!

ryanbab

i do

obyone

but it would be off topic so at this point I'd rather not....however, I will go as far to say that I question the knowledge of the person I communicated with regarding the results of the test...moreso since he didn't have a base sample to compare to...among other things.

ndahi12

"You THINK? Man - you are sounding like a REAL expert here! Do you mind telling me the source of these gems of wisdom? Why post something when you admittedly do not know what the he** you are talking about?"

Why the attitude? When an engine sits overnight oil will seep back to the oil pan. What is so radical about this? When do you check the oil level on your engine? You let the car sit for a while, right? Why do you do that? Because you wait for the oil to make it back to the pan in order to take an accurate measure with the dip stick.

The same principle applies here. The car sits over night and the oil drains back to the pan, leaving the DOHC valvetrain with little to no oil. When you start the car in the morning, it will be noisy/clattery until the oil runs through the engine.

minikin

he's not going to shut up; so maybe, please, if we just all ignore him, he'll go away.
-- Don