4.8L Piston Slap

[bhanson57]

An issue is arising around piston slapping in this motor.
It does not do it when the engine is new. It becomes noticeable when the engine has around 30k miles. The engine is not yet warmed up and the engine is gear and the rpms slightly above idle. The sound will be there until the engine reaches a normal operating temp. Upon further review with Toyota mfg. representive this is a normal condition.
It is not normal to have piston slap developing this early. I would be very leery about this engine and Toyota's position considering the engine in Toyota's higher end SUV's like the Sequoia. This engine calls into question Toyota's reputation for quality.......

[borneseller]

I purchased my '04 Sequoia in July '05 with 16,000 miles - - now has 27,000 miles and just noticed the same thing you did. Has been in the dealer's shop for two weeks total (2 separate times). Dealer is saying they "opened a case" on it - - "talked with Toyota corporate" - - corporate told them - - and now they're telling me it's the type of gas I'm putting in (can you believe that!). To me it sounds like there isn't enough pressure to keep the oil in the top part of the engine - - though they say the oil pressure is fine. It's under warranty but I'm thinking they won't really try and find the problem until I'm out of warranty. When a car company won't stand behind it's product - - it really makes you question your purchase. If anyone has a solution, I'm all ears.

[97cavalier]

here is the deal on that, gm has the same problem. The piston skirts are to short so when it is cold they hit agenst the cylender wall a little, when it is warmed up they expand and fit normal so it goes away. It does not happen when new because all the teflon has not worn off the pistons. i would run a synthic oil and a k&n oil filter because it has better protection and is known to sometimes help or reduce this. The k&n oil filter is needed because it flows more oil. But the dealers are trying to get out of it and save there ass's by saying it is normal. But think about it, if toyota replaces the motor, 30,000 miles later it will do it again because it is the same motor. Only way they can stop it is to put a bigger piston in, or one with a longer skirt.

[Brian R.]

I'm moving this to the 4Runner forum to see if there are more than two complaints about this.

BTW, the fact that GM has a problem with piston slap has no bearing on this issue in a Toyota engine.

[97cavalier]

i was just tell you guys that gm has same problem and what the problem is and how it is caused.

[Brian R.]

I don't think you understand how big an assumption you are making when you imply it's caused by the same problem affecting a totally different engine from a different manufacturer. There is more than one possible cause, and that's assuming that the noise in the Toyota engine is piston slap to begin with. A complaint about piston slap in the 4.7 L engine is very rare on this board. I have no recollection of any such complaint previously.