Toyota 3.5L V6 Piston Slap

[Drew1977]

I bought a certified 2010 Toyota Highlander with 40K miles a few months ago and soon noticed a distinctive knock on cold acceleration which diminishes as the engine warms up. Apparently the pistons in this engine have a short skirt and tend to rock a bit in these engines until they heat up and expand. There are many people driving all the toyota and Lexus cars with the V6 complaining of the dreaded piston slap.

Took it into the dealer who said it was pre-ignition due to carbon in the combustion chamber (yeah right) and did a de-carb service at no charge. Took it to a second dealer who said it was normal for these engines to sound like that as the different metals expand. At least I have it documented with a few years left on the warranty....

So, hopefully the piston slap isn't detrimental to the engine. What is a good 5w30 ( has the tow package) to minimize the sound and/ or any possible cylinder wear? I'd like to put in Mobil 1 at its next oil change.

 

[Danno]

Using Pennzoil Platinum 5w30 in my 2009 Venza with the 3.5L. Works well.

 

[KitaCam]

I second Pennzoil Platinum 5w30 synthetic oil...but also Pennzoil 5w30 conventional oil...both run Kitacam's I4 very quietly and smoothly...

 

[Clevy]

My 99 chev with a 5.3 has piston slap. At 280k+ it doesn't seem to be doing any harm.
Piston slap is common and doesn't seem to affect the longevity of the engines that suffer from it. It's an annoyance at its worst.

 

[gregk24]

PP, PU, M1, any quality name brand oil will take this engine very far. Dont be afraid of piston slap, its harmless.

 

[901Memphis]

Originally Posted By: Drew1977
I bought a certified 2010 Toyota Highlander with 40K miles a few months ago and soon noticed a distinctive knock on cold acceleration which diminishes as the engine warms up. Apparently the pistons in this engine have a short skirt and tend to rock a bit in these engines until they heat up and expand. There are many people driving all the toyota and Lexus cars with the V6 complaining of the dreaded piston slap.

Took it into the dealer who said it was pre-ignition due to carbon in the combustion chamber (yeah right) and did a de-carb service at no charge. Took it to a second dealer who said it was normal for these engines to sound like that as the different metals expand. At least I have it documented with a few years left on the warranty....

So, hopefully the piston slap isn't detrimental to the engine. What is a good 5w30 ( has the tow package) to minimize the sound and/ or any possible cylinder wear? I'd like to put in Mobil 1 at its next oil change.



Mobil 1 5w30 would be a fine choice. Might you also consider Pennzoil Platinum 5w30.

 

[Merkava_4]

Originally Posted By: Drew1977
Apparently the pistons in this engine have a short skirt and tend to rock a bit in these engines until they heat up and expand.


So why not fill up the space between the piston skirt and the cylinder wall ? Go thicker.

 

[Bambam]

If Clevy's engine is still going strong at 280k I don't think it matters what oil you use.

 

[Trav]

Originally Posted By: Drew1977
I bought a certified 2010 Toyota Highlander with 40K miles a few months ago and soon noticed a distinctive knock on cold acceleration which diminishes as the engine warms up. Apparently the pistons in this engine have a short skirt and tend to rock a bit in these engines until they heat up and expand. There are many people driving all the toyota and Lexus cars with the V6 complaining of the dreaded piston slap.

Took it into the dealer who said it was pre-ignition due to carbon in the combustion chamber (yeah right) and did a de-carb service at no charge. Took it to a second dealer who said it was normal for these engines to sound like that as the different metals expand. At least I have it documented with a few years left on the warranty....

So, hopefully the piston slap isn't detrimental to the engine. What is a good 5w30 ( has the tow package) to minimize the sound and/ or any possible cylinder wear? I'd like to put in Mobil 1 at its next oil change.


I wouldn't discount the dealers carbon explanation too quickly. As far as people complaining on forums, many times thats just misinformed individuals self diagnosing.
Some engines like the Cadillac N* and maybe this one knock loudly when cold and cleaning the carbon is really the answer.

I don't know if this engine is prone to carbon knock or not but the dealer did the right thing if nothing else than to rule it out.
Does it still knock? Sometimes they need to be cleaned out a couple of times before they a free of enough carbon.
Seafoam will not correct this if it is really the issue.

 

[Drew1977]

I realize this probably isn't the right venue to hash out details of carbon knock, but would you really expect it on a vehicle with only 40K miles? The second dealership did a careful evaluation, including listening with a stethoscope and came to the conclusion that the sound is "normal".

I'm just going to put in some good synthetic M1 or PP and plan on geting a compression test before the warranty is up. Thanks for the all the input!!

 

[tig1]

Carbon in the area of the piston and rings is caused by the conventional oil oxidizing and forming carbon deposits. A quality synthetic oil will prevent this from happening if used from the start. Ring coking is a main cause of engines using oil as the rings seal closed with carbon and allows oil and exhaust gases to pass by the rings. If you have this problem a quality synthetic over time may begine to loosen this up. Overkill, a member here, has pics showing carbon deposits removed from only one oil change using M1.

 

[Trav]

Originally Posted By: Drew1977
I realize this probably isn't the right venue to hash out details of carbon knock, but would you really expect it on a vehicle with only 40K miles? The second dealership did a careful evaluation, including listening with a stethoscope and came to the conclusion that the sound is "normal".

I'm just going to put in some good synthetic M1 or PP and plan on geting a compression test before the warranty is up. Thanks for the all the input!!


Like i said i don't know if this engine is prone to these issues like the N* but in a N* it can happen in a very short amount of miles if driven like an old lady which many were.
10K or once a year was not unheard of.

Those engines that were used at WOT once in a while usually had no problems.
I mean occasional WOT not driven like someone stole it or beat the thing to death.

 

[OVERKILL]

I believe Tig is talking about this:

Which eventually tapered off after many OCI's and probably around 50,000Km or so.

 

[smithph]

I have this engine in a Sienna. Piston slap due to zero-skirted Piston has been present since day one. I have tried many oils and found the synthetics and syn-blends 5w30's from Pennzoil and Valvoline help to mute the startup rattle the best based on my completely subjective and unscientific opinion. Note I said 'help' not 'eliminate'

That said I am about to try yet another one this weekend (Caterham blend = 4qts TGMO 0w-20 and 2.5qts Mobil 1 0w-40)

 

[strat81]

Originally Posted By: Merkava_4
Originally Posted By: Drew1977
Apparently the pistons in this engine have a short skirt and tend to rock a bit in these engines until they heat up and expand.


So why not fill up the space between the piston skirt and the cylinder wall ? Go thicker.


I went from 5w30 to 0W-40 in my GM 5.3 piston slapper. It helped reduce the noise, but it did not eliminate it.

Highway fuel economy has not been negatively impacted with the heavier oil. City fuel economy has always been terrible, especially in the winter.

 

[Ken2]

My Toyota 4.7 engine has had a cold piston tick since day one. It goes away as soon as some warmth develops in the engine--I drive it easy until them. Still going strong.

 

[afoulk]

The 2AZFE in my scion has the same issue. I've tried all the valvoline oils in 5w20 and 5w30, plus Pennzoil Conventional 5w20 that's currently in it now and none have really seemed to quiet it down at all. The only time it seems to improve is during the summer months when ambient temps are warmer at initial start up. My valvetrain does seem quieter with Pennzoil conventional however. I have some Pennzoil Conventional 10w30 waiting to go in next, but after that I'm thinking of trying some castrol edge w/titanium

 

[Ram01]

10w30 should help

 

[friendly_jacek]

Does yours sound like this:

 

[Merkava_4]

Originally Posted By: strat81

I went from 5w30 to 0W-40 in my GM 5.3 piston slapper. It helped reduce the noise, but it did not eliminate it.

Highway fuel economy has not been negatively impacted with the heavier oil. City fuel economy has always been terrible, especially in the winter.


I'd go thicker then. I'd try 15w40 or 20W-50 and see what happens.