friends truck 2011 1500 Chevy with the 4.8, he bought brand new and it currently has 61k miles. I started changing the oil for him at 40k, at 5k intervals. Besides one oil change where i used 5W30 PU and the current fill of 10w30 M1 EP, i have always used dexos spec'd oil in it from 40k to the current 61k. Cheapest filter i used was a Promotive once, usually use an ac delco pf48 or a fram ultra. Even before i started changing it, and still to this day, i usually crawl under it after to check for leaks and such, i always hear a slight tapping noise coming from the bottom end, it also does it when the engine is completely warm and has had a good run on the road. so pretty much all the time. Its not very loud, but noticeable. Could it be the infamous piston slap these vortecs are known for, or was the problem fixed by '11? With the short 5k runs on synthetic, im thinking of just using Castrol GTX synblend 5W30 from here on out, which is dexos specd, with an ac delco filter and calling it a day. good choice? Thinking of adding half a quart of either lubegard biotech or MoS2 to each oil change or is that not necessary?
piston slap
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it runs great and doesnt burn oil, just that slightly annoying tapping noise
I just made a 6 hr trip and started noticing some noise coming from the engine that I would call piston slap as well. This is the 3.0 Duratec engine and I am running Mobil1 0w20. Very disheartening considering I am at 106,000 miles now. Is this likely going to damage the engine?
Originally Posted By: spk2000
I just made a 6 hr trip and started noticing some noise coming from the engine that I would call piston slap as well. This is the 3.0 Duratec engine and I am running Mobil1 0w20. Very disheartening considering I am at 106,000 miles now. Is this likely going to damage the engine?
The duratec engines aren't know for piston slap, its mainly just the GM engines. I have an 01 taurus with the vulcan and edge 0w20 it in. It purrs like a kitten.
I just made a 6 hr trip and started noticing some noise coming from the engine that I would call piston slap as well. This is the 3.0 Duratec engine and I am running Mobil1 0w20. Very disheartening considering I am at 106,000 miles now. Is this likely going to damage the engine?
The duratec engines aren't know for piston slap, its mainly just the GM engines. I have an 01 taurus with the vulcan and edge 0w20 it in. It purrs like a kitten.
I have a 09 chevy truck that has the same sound. Nothing seems to quite it down. I've tried Mos2 and a few different oils & filters with no noticeable differences. The good thing is that the lab says everything is fine when they look at my oil.
Bottom line, it's just a noise that goes with the design of the engine. Don't lose sleep over it.
Bottom line, it's just a noise that goes with the design of the engine. Don't lose sleep over it.
Because the use of short skirt cam ground pistons has become pretty much universal (to reduce internal friction and improve piston to cylinder sealing), most modern engines from most manufacturers have a least a little piston slap noise, particularly when the pistons are cold before they heat up to become round (cam ground pistons are slightly oval shaped when they are cold). No harm comes from this noise. Ignore it.
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My '96 GMC had piston slap from about 3000 miles to 143,000 miles when I got rid of it. Never burnt any oil and ran fine.
There are a lot of Hondas out there with piston slap - J V6s and KI4s ... Never hear anything bad about them.
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My '00 Silverado has it and I feel bad if he has it too. Even though many people say it is harmless and does not effect durability or longevity of the engine, it is annoying to me every time I hear it. I would take a less powerful but quiet engine any day over a slapper. I cringe when people say just start up and go. If I did that with my truck at 50 degrees or colder, it sounds like the bottom end is going out. A little warmup time (2 minutes min. 50 degrees/4 minutes 20 degrees) goes along way for my truck, and I could care less about wear or fuel dilution. Burns/leaks 1/2 Qt. every 5,000 miles with 241,000 miles on truck. My worn out 305 '78 Chevy C10 with 337,000 miles is quiet as a mouse in any temp. Go figure? . I thought by now GM would have gotten that issue fixed for good. Maybe not. FWIW, PYB5w30 is quieter than PP5/10W30 in my truck. Something to think about....
Back in the 70's we were replacing a lot of pistons in engines that had slap under warranty , now it seems to be accepted .
Personally I feel there should be some better engineering done as it really is unnecessary . A bit when the engine is cold is OK but IMHO it should be gone when the engine warms up .
Personally I feel there should be some better engineering done as it really is unnecessary . A bit when the engine is cold is OK but IMHO it should be gone when the engine warms up .
I think ill either use Castrol SynBlend 5W30 with an AC Delco PF 48 for 5k ocis or Castrol Edge with Ti 5W30 and a fram ultra and go for 7k or until olm hits 20%
The local Ford dealer, when dealing with the modular truck engines and "piston slap" simply installed 10W-40 synthetic. For the most part, it cured the piston slap.
Part of the program was to perform UOA's to ensure no increase in engine wear. They found, to their surprise that the UOA results improved markedly.
Obviously, from a scientific standpoint, the results they obtained apply only to Ford Modular truck engines. By the way, the program was so successful (as Ford was replacing engines regularly due to the noisy start up knock) that it was extended into "helping" later model "cam phaser" knock problems, and eventually morphed into a TSB. That TSB has since been removed from the database for unknown reasons. I suspect some pressure due to EPA requirements. As the "cure" worked.
Part of the program was to perform UOA's to ensure no increase in engine wear. They found, to their surprise that the UOA results improved markedly.
Obviously, from a scientific standpoint, the results they obtained apply only to Ford Modular truck engines. By the way, the program was so successful (as Ford was replacing engines regularly due to the noisy start up knock) that it was extended into "helping" later model "cam phaser" knock problems, and eventually morphed into a TSB. That TSB has since been removed from the database for unknown reasons. I suspect some pressure due to EPA requirements. As the "cure" worked.
Even with Mobil 1 0W-20 in the sump this fall, our CR-V's engine has taken to slapping quite a bit when cold. This oil previously worked pretty well to keep the engine quiet.
I drained a quart out the other day and replaced that with a quart of Mobil 1 0W-40. There is a dramatic difference in engine noise with the boost from the heavier oil. I have run Mobil 1 0W-30 before in this engine, and have felt that it was quieter than the 20 grades I've used. I may simply do that from now on...run 30 grades.
The difference in fuel economy is not measurable for me.
I drained a quart out the other day and replaced that with a quart of Mobil 1 0W-40. There is a dramatic difference in engine noise with the boost from the heavier oil. I have run Mobil 1 0W-30 before in this engine, and have felt that it was quieter than the 20 grades I've used. I may simply do that from now on...run 30 grades.
The difference in fuel economy is not measurable for me.
My engine has had piston slap since I had it, and it's now at over 200,000 miles and runs fine. The 2003 Malibu we have in the family has over 146,000 miles on it and it's piston slapped since new, still runs fine and doesn't burn any oil.
The slap is caused by excessive space between the piston skirt and the cylinder wall.
Fill the space up with thicker oil. Done. Your special DEXOS approved 5W-30 is too thin.
Fill the space up with thicker oil. Done. Your special DEXOS approved 5W-30 is too thin.
Baloney, that is completely wrong. The oil control ring scrapes the oil off the cylinder wall, your idea is not square with reality....
Originally Posted By: SteveSRT8
Baloney, that is completely wrong. The oil control ring scrapes the oil off the cylinder wall, your idea is not square with reality....
The oil control ring is there to keep the oil under control, not to scrape the oil off the cylinder wall. Piston rings are spring loaded. When the oil film is thicker, the ring gap closes up ever so slightly to accommodate the thicker film of oil.
Baloney, that is completely wrong. The oil control ring scrapes the oil off the cylinder wall, your idea is not square with reality....
The oil control ring is there to keep the oil under control, not to scrape the oil off the cylinder wall. Piston rings are spring loaded. When the oil film is thicker, the ring gap closes up ever so slightly to accommodate the thicker film of oil.
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