Time2Rock

Howdy Folks. I am hoping somebody could help me get an idea of what might be wrong with my car. I have a 2007 LS460L, purchased from a private party. The valve springs SB was done by Lexus of Tucson. The following has been occurring:

On 5 separate occasions. The car begins to shake and buck and loses power. Engine warning light comes on steady, not flashing. Anti slip light comes on. Car can be driven up to about 20 mph but it will be missing badly. Attempts to shut off the car and restart don't seem to make a difference. If I drive the car it will suddenly "fix" itself within one to five miles. The car will behave completely normal after that for some time. Warning lights stay on until the car has been turned on and off two more times and then they clear.

Temperatures and atmospheric conditions don't seem to impact when it happens as it seems to occur both when really hot and when temperate.

I live a long distance from a Lexus dealer so I took it to the local repair shop that fixes Lexus in our area. When he turned the car on it had ceased shuddering and operated normally. He ran computer checks and the codes indicated that three cylinders had been missing. Full diagnostics could not turn up the source of the problem. He hooked it up in tandem with another 2007 LS460 and ran performance tests on both and they read pretty much identical. He decided that the plugs looked a little dirty so we changed the plugs. ( I think he needed to feel like he could charge something so he did something he hoped would work). He had the car testing it and driving it around for 10 days before he gave it back and it never acted up on him.

It has continued to randomly malfunction. When the car runs right it runs beautiful. We thought it might have to do with having a low fuel level in the gas tank and some kind of a vapor lock so we started keeping the fuel level up above half a tank and the problem seemed to stop for a month but last night it happened again with a full tank. The car is generally driven around town, 95% pavement and 5% dirt road. Trips no more than 15 miles round trip. The local repair shop has not returned my call.

So the questions are:
Does anybody have an idea of what this might be?
Can anybody recommend which Lexus dealer in Tucson to take it to as there are two there.

I would like to have an idea of what it might be before I take it in, knowing that it probably won't be acting up when it gets there.

Thanks

JFNash

Welcome to the club.

The 1st suspect: the valve springs fix. Some people have reported problems after getting the VSR fix done. This could be one of those instances where something isn't right about the VSR fix. Or at least you need to start from there.

Given your situation where you live far away from a Lexus dealer and it would be very frustrating if you described the problem to them and they couldn't replicate the problem, I suggest you keep a video camera with you and film the symptoms.

I assume that you're out of warranty. If that's the case, you need to build a case where the dealer that performed the VSR fix should have it checked for possible problems originating from the fix work itself. This way, you can push Lexus to fix your problem or even hold them liable in case the fix is taking a long time or isn't possible at all.

Try to find alternatives to replicating the problem at the dealership since trying to do so may just extend your hassle with the car and the dealership. If you can't find a better idea, just do the videotaping thing and show it to the dealer so they can't just say well we couldn't replicate the problem and here is your car!

edarte

The odds are really against this but have you checked the gas cap? I suspect it would show up on the diagnostics but I mention it just in case.

I had a problem with my previous LS 430 where a failing gas cap caused mild stalling and, once the warning light came on, it did not reset until after several starts and restarts.

jmcraney

Well, when you have these sorts of problems it can be stressful. And you have to start trying something if the experts are unable to provide any help.

Maybe the first thing to do is sort of categorize the problem for something to try.

I would divide the possibilities into categories such as mechanical, electronic/electrical and fuel.

The mechanical possibilities are things like valve springs, broken valves, piston rings, etc. those sorts of problems usually are not intermittent or self healing. So what you have told us doesn't seem to fit that category.

Electronic/electrical possibilities are ignition-electronics, computer components that control the engine, spark plugs, engine sensors that provide feedback to the engine control computer. These can be intermittent but usually they are not. However the control sensors problems usually leave a data trail in the engine control electronics. Since the error codes didn't give any good clues then a sensor is probably not the problem.

That just leaves the fuel system which is part mechanical and part electronic. Sounds like maybe the fuel flow is being interrupted. The first thing I would check is the "Fuel Rail Recall" to be sure that it has been done. Seems like the issue with that, and my recollection may be wrong, was that the fuel delivery pipes were aluminum and not satisfactory for ethanol because of the water in the ethanol would corrode the inside of the pipes and the shedding would block the fuel flow.

cmasten

jmcraney is right on the money here. I agree with JFNash as well, capturing the situation may help the dealer to discern the problem. These situations are always tricky and you want to make sure they treat the Problem.. and not the Symptoms..

The LS is a complex animal, there are many variables that could be part of this "Problem". I would also think that the computers data would provide some evidence but that may require capturing those data points, unfortunately that means living with the "Symptoms" for a while longer.

I would contact a Lexus dealer and let them know your situation, they may offer you a loaner and they have more extensive tools to diagnose this issue, they also have access to Lexus corp resources which your local person will not.

Time2Rock

Thanks for the guidance. I had been thinking along the similar lines of I don't think it should be mechanical because of the intermittent nature of it. It would seem if something is broken or misaligned that it would give me a more consistent problem. Same for the electric system, why would driving it around at low speed for a short time fix the problem. The cars are so complex that anything is possible but it seems like it is starving for fuel. The only thing I don't get is why the computer would read only three cylinders misfiring instead of all eight. I will take video from the phone camera the next time it happens so I can show the techs.

I also did not see any mention of a fuel rail repair being done when I looked at the past service records so that could be a possibility.

I thought perhaps the next time it happens I might pop the gas cap to see if that changes anything. Any thoughts on that/ dangers?

Thanks again

cmasten

no dangers, just not sure it will help I think the issue is bigger than the cap. I take mine off all the time to add Techroline injector cleaner with the motor running. Fuel Rail update is a very likely candidate, your symptoms mirror those very closely. Its a service recall so free of charge and a dealer will give you a loaner

Time2Rock

I checked with Lexus of Tucson and they said the fuel rail recall had been taker care of on this car already. I am going to go ahead and take it to them next Monday so they can see what they find and I will pray that it acts up while there and they can track it down. Thanks for everybody's help. I felt much more confident in discussing the problems and issues with him having read all your comments.

cmasten

ask them for a loaner, and im sure they will find it from the logs in the computer. Let us know how it turns out.

us254559

I own a 2007 LS460, 31,000 miles and I live in hot climate (Austin, Tx). My car had the VSR replacement and the fuel rail warranty work done by 1st owner. I bought the car six months ago and had similar issues, where my car would hesitate and sputter and it felt like it would just stall, no matter what position the throttle was in. I could floor it and it simply would not accelerate...it felt like it was running very lean and starving for fuel. The problem disappeared after about 10 minutes of driving. During this warm-up time, when I was able to get up to 45-55 mph, it would also surge back and forth...like it was misfiring.

1st time I took it in for minor warranty issues I told the svc rep about the problem and he told me to drive it more aggressively....he said it would readjust to my fairly easy driving style....however it did not make any difference.

2nd time I took it in and went to a different svc rep and got the problem resolved. They installed a new revision software in to the ECU. I now have no problem and plenty of acceleration when the car is warming up. I have never had the problem again. The only difference that I can tell between our cars.....I got no warning lights that came on.

Time2Rock

I can only hope that it ends up something simple. I guess I hope more that they figure out what it is or I will have to part ways with the car as it is too unsafe to drive this way. If she decides to stall at the wrong time it could be a nightmare.

jlawr

If you have less than 100k miles, the drive train should still be in warranty id the VSR was done. Ask for a computer (ECU) firmware update. All should be at N/C.
Good Luck

Time2Rock

So I took the car into Lexus of Tucson. Predictably they found nothing wrong with it. They acknowledged the error codes indicating cylinders 1,6,and 7 had all misfired. These were the same three cylinders which had shown up as a failing before. Coil #3 has been previously replaced so they switched the coils from cylinders three and 7 and sent it back home to us. The thinking being if the problem moves they will replace all 3 coils. I doubt that is the problem. If the problem does not change cylinders then they have no clue what is wrong but will keep trying to figure it out. I know the car will fail again. I just hope it does it soon.

xole

This might be a stretch but another possibility.

Hesitation on Acceleration

delta9mda

am doing research and was looking around here. my car stalled and had the engine light and traction control light come on. pulled over and turned it off. started it up and was all good. took it to the dealer and i was told there is a service bulletin out for a piston problem.

car is now getting pistons replaced n/c to me. getting all fluids changed out too (obviously).

will check back to see if anyone else is getting this. ill call my service person tomorrow and ask for details so i can pass it on here.