Hi,

2010 Lexus GS460 180k miles.
My engine keeps stalling when engine is hot. No warning lights, reading errors says running lean.
Any hints?

Thanks Chris

 

Maybe a dirty or faulty MAF sensor, leaks in the intake system, faulty upward O2 sensor?

Also check if you have any fuel leaks, maybe the high pressure pump connection to one of the cylinders is leaking?

 

Hello,

dealer and other car services still dont have any clue what is wrong with the car.
The car keeps stalling.
The car trys to keep the engine running but at idle speed the car stalls,
Revving the hell out of it solves the problem for a short time.
Errors are bad cats, running lean.
Maf changed
Temp sensor changed
fuel pump changed
throttle body changed
spark plugs changed

sometimes the car just runs fine

 

Sounds like your cats are clogged and choking your engine. If youre getting an error code for bad cats then I would unbolt the flange from the inlet of the cats and test drive the car to see if it stalls and dies out on you.

Are you getting any misfires?

 

Hi,

I checked the cats wth an endoscope. All four looked perfect.

Christian

 

Try searching in LS460 forums as you guys share the same engine, and there are many members with high mileage LS's.

Another thing you can do is buy a techstream ($29) adapter and with a laptop monitor the car, the same can be done with a good scan tool. This will atleast help guide you onto what is shutting down or giving you issues.

Im thinking maybe a fuel injector is giving you an issue once it warms up. Or an o-ring vacuum on the injector but these are guesses and diagnosing is always best. Why not take it to the dealer and pay them 1 hours worth of diagnostics?

 

Already went to 2 different dealers.
They really dont know what is wromg with car. Even after reading the error codes.

Christian

 

What are the error codes? Just bad cats? Running lean?
When did you change your battery?

 

Have they checked the crank position sensor yet? This can cause issue while hot and not throw a check engine light

 

Hey Christian, did you ever solve the issue?

 

I'm also interested if you found a solution as I own a 460. Keep us posted.

 

No,
still not solved the problem.
Just changed the maf but it didnt change anything.
Sometimes the car runs just fine. and espiacially at city driving with low revs the car acts weired and stalls.
Hard to start, only with keeping the revs up with the accelartor it starts.

Thanks Christian

 

With such high mileage I bet its from carbon build up, when was the last time you opened the throttle body and cleaned it out? If never then most likely thats part of your problem.

I would recommend you unbolt the throttle body and clean it thoroughly on both sides. This is usually a good sign if your engine has carbon and or oil residue. Then with the car warmed up do a top engine cleaning with seafoam or BG or any other good solution thats good for carbon and run it through the top of the intake manifold for about half the bottle and then turn off the engine to allows the chemicals to soak into the carbon. Then keep repeating the process

 

Maybe try a fuel injection cleaning, sounds like it's something with the fuel supply

 

Hi,
changed

throttle body
Fuel filter
MAF
Fuelpump
Tempsensor
sparkplugs

next on the list
crank position sensor

Christian