Need Help - Ls400 Idle Very Rough

[phabej]

The timing belt broke on my LS400. I took it to small dealer nearby and he said the valves were bent. He did a compression there was none. It cost me $1200 to fix it. The fixed include replacing the two heads plus labor for putting everything back on. Now the car is running, but the car idles very rough at parking. The RPM jumps up and down constantly like crazy. The engine is making loud noises like you press on the gas and release. The machanic told me that it was because the computer did not reset itself yet. It will go away after driving it for a while. I'm just curious if this is normal after replacing the heads and timing. I'm open for any suggestions or advice. Thanks.

[nc211]

The timing belt broke on my LS400. I took it to small dealer nearby and he said the valves were bent. He did a compression there was none. It cost me $1200 to fix it. The fixed include replacing the two heads plus labor for putting everything back on. Now the car is running, but the car idles very rough at parking. The RPM jumps up and down constantly like crazy. The engine is making loud noises like you press on the gas and release. The machanic told me that it was because the computer did not reset itself yet. It will go away after driving it for a while. I'm just curious if this is normal after replacing the heads and timing. I'm open for any suggestions or advice. Thanks.

1st of all, what year is your car???? Depending on your model year, will tell us if your valves were truely bent or not. Pre-95' model engines were non-interference....aka...your timing belt can break w/o further damage.

2nd, the part about "The machanic told me that it was because the computer did not reset itself yet. It will go away after driving it for a while." is crap. I assume he unhooked the battery during the repair in the first place. Unhooking the battery for a few minutes will reset the computer in general. It sounds to me your idle module is way off. You know, the indi mechanic's can tear down, and rebuild, but it takes a little more than a torque wrench to "tune" these engines.

I'll let some of the other, more knowledgable guys chime in on this one, as I have not had the need to mess with the engine on my car, yet...

By the way....WELCOME to the club! You should post up your model year in your profile! We like pictures too!

[93ls400walt]

just some early advice. Take a look around the engine. Look for any loose,cracked or disconnected vacumn hoses.

[phabej]

Thank you very much for the information and advice. My car is a 1992 Lexus LS400. The idle problem only appear when parking. While driving the car seems to run normal. I have not had a chance to look at the engine closely yet. Will do as soon as I can.

[SRK]

Your mechanic could not have replaced the heads for $1200.00. He probably just installed a timing belt and gouged you that kind of money, while mis-timing it during installation. The surging idle could also be a large vacuum leak on the intake side.

One of the wonderful things about modern engines is that one simply assembles them correctly, and then they do all the tuning. There is no fiddling with them. Set the cams, set the distributors in place, and the timing is perfect and the engine is happy.

So the idea that the valves were bent and the compression was zero is crap. If he actually said that, you must consider him a liar.

[phabej]

Ok. So you are saying that I got ripped off for the heads. There is no need to replace the heads since it is not an interfaring engine? Is there a way tell if the heads had been replaced?

One thing I forgot to mention on the car is that when I picked up the car, I noticed the plastic coolant tank is completely empty. The tank if now filled with coolant, but not sure if there is any bubble inside the coolant system. Would bubble inside the coolant system cause the idle to behave that way?

[nc211]

I'm not sure how to check that w/o tearing it down again to check. It sounds like to me though that yes, you probably got taken for the heads. However, $1200 for the timing belt is in line with what a lexus dealership would charge you. He probably quoted you from their numbers for the timing belt. I would demand the mechanic prove to you the heads were the problem. Quiz him on how a non-interference engine could be damaged by the timing belt breaking??? I'd be interested to hear his response. Listen to SRK on this, he knows his stuff about these engines, that's for sure.

[phabej]

I'm not sure how to check that w/o tearing it down again to check. It sounds like to me though that yes, you probably got taken for the heads. However, $1200 for the timing belt is in line with what a lexus dealership would charge you. He probably quoted you from their numbers for the timing belt. I would demand the mechanic prove to you the heads were the problem. Quiz him on how a non-interference engine could be damaged by the timing belt breaking??? I'd be interested to hear his response. Listen to SRK on this, he knows his stuff about these engines, that's for sure.

After driving the car for a while, I noticed something is very wrong with the car. As soon as the gear is switched to driving, the car starts to accelerate and continue to increase in speed even though the foot is not on the gas pedal. While driving on highway the speed thermometer will remain at the same speed even though the foot has been moved away from the gas pedal. It's like having cruise control ON. Step on the break and the speed drops. As soon as the break is release the speed goes back up again. I'm thinking there might be a short somewhere. Anyone has any suggestions? I'm taking the car back to the shop tomorrow for the dealer who fixed it look at it again. He had my car for 4 weeks before he could fix the timing belt. And now this new problem after he put on the timing and supposely new heads. I'm starting to lose confident on him that he can fix my car. Any ideas or suggestions will be greatly appreciated. Thanks.

[SRK]

You should have someone familiar with these cars look at your engine first. They will be able to tell if hoses and wiring harnesses have been disturbed and are out of place. Lexus makes the most beautiful wiring looms I have ever seen, and they fit perfectly when replaced perfectly. Many mechanics don't replace them properly and it will show.

As to the cylinder heads, you would see "wrench" marks on the bolts, like those holding the intake manifold on, and probably the nuts and studs on the exhaust manifolds. But it takes a trained eye to see it.

The problem you face now is that the guy that screwed up cannot be expected to fix it. He has lied about the big job he claims he did, and has been proven to unable to do the smaller job he overcharged you for. And he took a month to do it.

Get it fixed properly, and then show him the new bill and make your intentions clear to recover your initial costs through the courts.

You did get an itemized bill from him didn't you?

[phabej]

You should have someone familiar with these cars look at your engine first. They will be able to tell if hoses and wiring harnesses have been disturbed and are out of place. Lexus makes the most beautiful wiring looms I have ever seen, and they fit perfectly when replaced perfectly. Many mechanics don't replace them properly and it will show.

As to the cylinder heads, you would see "wrench" marks on the bolts, like those holding the intake manifold on, and probably the nuts and studs on the exhaust manifolds. But it takes a trained eye to see it.

The problem you face now is that the guy that screwed up cannot be expected to fix it. He has lied about the big job he claims he did, and has been proven to unable to do the smaller job he overcharged you for. And he took a month to do it.

Get it fixed properly, and then show him the new bill and make your intentions clear to recover your initial costs through the courts.

You did get an itemized bill from him didn't you?

Yes, I did get a received from him showing that I paid $800 for the two heads, $400 for his labor and $66 for shipping. He made it sound like he did replaced the heads, but I have a feeling that he didn't. And now this problem of the idle jerking which he doesn't seem to be able to fix it. Let me ask a question, if he can't fix this idle problem and I take it to a Toyato dealer to have it fix. Who is responsible for the cost incurred from the toyota? Can he be liable for the cost because he screwed it up and cannot fix it?

[SRK]

If you take your car to another repair shop ( hopefully a good one ), you are responsible for that bill. It is a contractual obligation. They don't care that you selected someone else previously to mess up your car. You want them to fix , they fix , you pay.

So he charged $400.00 labour to replace both cylinder heads? Guy works quite quickly. I would think the flat rate on that job would be about 15 hours or more.

Anyhow, you get the car fixed and pay the bill. Then you take him to small claims court to have him pay you for the correct repair, and maybe even the work he screwed up. Then again you may just have to eat the entire cost and consider all a life lesson.

[phabej]

If you take your car to another repair shop ( hopefully a good one ), you are responsible for that bill. It is a contractual obligation. They don't care that you selected someone else previously to mess up your car. You want them to fix , they fix , you pay.

So he charged $400.00 labour to replace both cylinder heads? Guy works quite quickly. I would think the flat rate on that job would be about 15 hours or more.

Anyhow, you get the car fixed and pay the bill. Then you take him to small claims court to have him pay you for the correct repair, and maybe even the work he screwed up. Then again you may just have to eat the entire cost and consider all a life lesson.

I agreed with you. At first, I thought if he could replace the two heads plus putting the timing belt and everything back on for $1200, that is a great deal especial it would cost around $1500 going to Lexus to just have the timing belt put on. Appearantly, I was wrong. He lied to me and now he also create another problem. To be honest I don't think he knows what he's doing now. I remember he told me that he couldn't figure out why the idle is jerking. He told me to drive it for a while and it should go back to normal, but so far it still doing the same thing. I just dropped off the car this mornning for him to look at it again. This time, I wrote him a letter and include all the suggestions that everyone have given me here on how to fix it. I gave him until Monday to have it fix. If by then he still cannot fix it, then I am taking the car to Toyota to a have a look. It's been going on for too long and I am running out of patient waiting for him to get it fix. He told me it will only be a week, and now it's been 4 weeks and I still don't have my car back. THANKS MUCH FOR YOU INPUTS.