Piston Slap

[mcmann]

My 2007 GX 470 has 20,000 miles. Around 12,000 miles it started making what I called an engine knock when the car was first started and lasts between 2 to 5 minutes at idle. This only seems to happen after the car has been sitting overnight or parked for a day or two. It happens regardless of the outside temperature although it is louder when it's cold. The Lexus dealer yesterday said it was 'piston slap' and since it goes away after a few minutes it's a normal sound. He said it was the sound the piston makes as it goes up and down inside the aluminum tube and after it warms up it goes away. I asked if it was normal why didn't my other 2 Toyota SUV's ever make the sound (2001 Sequoia, 2004 LX 470)? He said some do, some don't. He also said some do it day one others after many years and some never do it at all.

Does this sound like a reasonable explanation? Next week a technical specialist from California is scheduled to examine the car.

[1990LS400]

Here are all the threads on this forum that contain the phrase "piston slap": http://us.lexusownersclub.com/forums/index...Cpiston+slap%5C

I thought piston slap was an artifact of the 1950's but I guess not -- amazing number of hits when I google "piston slap".

It might not be as noticeable if you don't let the car idle "2 to 5 minutes" after starting. My favorite words on warming up a car are from "Click and Clack" -- Tom and Ray from the Car Talk radio program on NPR:

"Unless it's below freezing, cars don't need to be warmed up at all. Driving them gently is the best warm up there is. If it's 25 degrees out, you might want to let it warm up for 30 seconds. If it's 10 degrees out, warm it up for a minute. If it's -10 degrees out, move somewhere warmer."

[mcmann]

Thanks for the link to the other piston slap entries. I'll check them out. Actually I don't let the car idle that long. The 2 to 5 minutes was my test to see how long the noise lasted. And it's louder inn reverse than in park or forward. If I back out of my driveway it's significantly louder than if I drive out in forward. Thanks again- even if the Supreme Technical Expert from California deems this a normal noise next week I'm disappointed.

[NicLX470]

You use premium fuel? If not that might eliminate some of the problem.

[mcmann]

I always use Premium fuel. I have a Sunoco station nearby and purchase my gas there.

[mann777]

Guys Maybe I am wrong but this does not sound to me Piston Slap but a Cylinder Piston Baffle which is within the cylinder head. There was issues on certain GX models and TSB rolled out for this symptom. Go back to you dealer, and ask him not to give crap story "as this will go away after few minutes". My friend has a similar symptom and they lied exactly the same way and did not do the job, until one day, it was unable to bear, And he made a issue and gave his peice of mind. Finally they replaced the cylinder head.

[mcmann]

Guys Maybe I am wrong but this does not sound to me Piston Slap but a Cylinder Piston Baffle which is within the cylinder head. There was issues on certain GX models and TSB rolled out for this symptom. Go back to you dealer, and ask him not to give crap story "as this will go away after few minutes". My friend has a similar symptom and they lied exactly the same way and did not do the job, until one day, it was unable to bear, And he made a issue and gave his peice of mind. Finally they replaced the cylinder head.

Thanks for taking the time to respond. I'm dropping off the car tomorrow night and the 'regional technical expert' is scheduled to examine the car on 12/10. I just called the Service Manager to alert him to this issue and our dissatisfaction with their excuses. This GX is my third Toyota (previous cars 2004 LX470 and a 2001 Sequioa) and the first to make this obnoxious knocking when you start the car. My lease is up in April and since I only have 20,000 miles we've decided to purchase it. But I'd have serious doubts about keeping it if they cannot correct the problem.

[mcmann]

Update on piston slap. Dropped the car off at Lexus of Cherry Hill NJ and the FTS (factory trained service technician) examined the car and found that "it's performing as designed." That is all they wrote on my service invoice. I thought it was interesting that there was no mention of the noise or it's cause. I called the head of the service department to ask about this and he commented that since the FTS says it's normal he can't do anything even if he wanted to.

Tomorrow I'll call the dealer's customer relations contact and see if they will rewrite the service invoice - I would like to have more documentation for my records in case something else develops in the future. Luckily I still have a full year of warranty left.

[mann777]

Update on piston slap. Dropped the car off at Lexus of Cherry Hill NJ and the FTS (factory trained service technician) examined the car and found that "it's performing as designed." That is all they wrote on my service invoice. I thought it was interesting that there was no mention of the noise or it's cause. I called the head of the service department to ask about this and he commented that since the FTS says it's normal he can't do anything even if he wanted to.

Tomorrow I'll call the dealer's customer relations contact and see if they will rewrite the service invoice - I would like to have more documentation for my records in case something else develops in the future. Luckily I still have a full year of warranty left.

McMann ..they will not give up easily, take another car, and ask them to compare when there is that song playing from your engine and one that is'nt, Simple, Ask them to fix it, than telling stories of design. I think you are being taken for a ride, dont be soft, its your car, and it is you should be having the satisfaction than they convincing you of the design plot. Beat it !!

[mcmann]

Update on piston slap. Dropped the car off at Lexus of Cherry Hill NJ and the FTS (factory trained service technician) examined the car and found that "it's performing as designed." That is all they wrote on my service invoice. I thought it was interesting that there was no mention of the noise or it's cause. I called the head of the service department to ask about this and he commented that since the FTS says it's normal he can't do anything even if he wanted to.

Tomorrow I'll call the dealer's customer relations contact and see if they will rewrite the service invoice - I would like to have more documentation for my records in case something else develops in the future. Luckily I still have a full year of warranty left.

McMann ..they will not give up easily, take another car, and ask them to compare when there is that song playing from your engine and one that is'nt, Simple, Ask them to fix it, than telling stories of design. I think you are being taken for a ride, dont be soft, its your car, and it is you should be having the satisfaction than they convincing you of the design plot. Beat it !!

I got absolutely no where with my Lexus dealer. I even spoke with the head of the dealership who claims that his new sedan has the same problem and that it's just something that happens with some vehicles with this specific engine. He assured me that it will not cause any harm. I even tried my backup plan - my company leases a new car every 3 years, the lease on this GX is up in April and I told him that because of the way they handled this we would look elsewhere for a new SUV. He didn't care.

[mann777]

MC...they are not only dealer in the world..see a another one..maybe they would be positive, dont give up.

[JayMo]

MC...they are not only dealer in the world..see a another one..maybe they would be positive, dont give up.

I have a 2007 ES350 and complained about the noise back in '08. Every year it gets louder and now even after the car is warm and I let it sit an hour it slaps for the first couple of miles. I have started a discussion with Lexus and have been to the dealership. Last week when I went in and told them what I wanted to talk about I was escorted into an office with 2 service writers. I got the same BS that this is probably piston slap and perfectly normal. I told them piston slap is not normal and I have never been in any gas powered vehicle that sounds this bad at startup. I also told them about posts I have seen and all I got back was blank stares. I am convinced they know all about this and how to fix it but have been instructed by Lexus to try and ignore the problem. I don't buy for one minute that this will have no long term effect on the engine. With all the bad publicty out there for Toyota right now I believe it is time for anybody with this issue to turn up the heat. The dealer did keep my car overnight and told me he drove it twice and it was no louder then any other loaner. Total BS. They are going to have a tech drive it Monday morning. If they still won't admit to the problem I am going to insist on a factory rep drive it cold with me in the car and also take out some of the loaners. If that does not work I plan on talking to the local media. There was just an article in Sunday's paper about a lady who had the sticking gas throttle problem and few years back and they kept telling her it was not a problem with the car.

[mann777]

Here is the TSB copy i was mentioning on my earlier posts.Hope it helps.

Cylinder_Head_Cover_Oil_Baffle_Precaution.pdf

[xxstewart]

Mcmann -- is your oil consumption normal? I'd take the car to an independent mechanic and get a second opinion. A competent mechanic will be able to determine if the pistons are slapping. Really like the service invoice -- "performing as designed" -- I think that's what Toyoda said about the gas pedals last week.

Mann777 -- interesting theory about the cylinder piston baffle -- if it gets damaged, what's it end up hitting that makes a noise?

[mcmann]

Mcmann -- is your oil consumption normal? I'd take the car to an independent mechanic and get a second opinion. A competent mechanic will be able to determine if the pistons are slapping. Really like the service invoice -- "performing as designed" -- I think that's what Toyoda said about the gas pedals last week.

Mann777 -- interesting theory about the cylinder piston baffle -- if it gets damaged, what's it end up hitting that makes a noise?

Thanks for the information about the baffle.

Oil consumption is normal - everything is normal except the slap. I will take the cylinder piston baffle print out with me and talk to the dealer. However I am also looking at trading it in on a new vehicle - maybe a 2010 GX. or LX. The Blue Book value is great, the car only has 20,000 miles and one year of full warranty left. But at this point I'd also like to tell my dealer he just lost a customer over this even though I know they don't care. I'm also looking at a MB GL, an ML and a BMW X5.

How would a mechanic determine if the pistons are slapping or not? What test is performed? I did get their chief mechanic to say that the only solution would be a short block but he couldn't guarantee that would work. But I agree with everyone here - even if they are slapping that's not acceptable.