I did some searching on the forum and didn't see this particular scenario, so here goes.


2006 IS250, Mileage 136,000K, All Recalls Completed


Had a tune up last week due to engine light and rough idle (makes sense - sparkies not replaced since 60K). During plug replacement tech mentioned the valve cover gaskets were bad and oil was leaking into the plug wells. Replaced the intake manifold gasket and valve cover gaskets.


Ever since, I had been smelling a burning smell AND raw gas through heating system. Burning smell was at rest and driving - raw gas smell was only at rest (lights, idling, etc.). Brought it back and tech confirmed manifold gaskets not seated properly so they reset them. They claim to have checked entire engine and found no gas leaks or puddled gas.


Got it back today and the burning smell is gone but the gas smell is still there when sitting at lights/stop signs.


Anyone have any ideas? I can't understand why this is only happening at rest, unless it has something to do with the vacuum system, which my understanding is much stronger when driving.


Not sure what to do at this point - tech is a best friends friend and the company has a great reputation. I dread bringing it to dealership.


Thx,
Les

 

any chance the car had its cats removed before purchase?

 

Does it smell like if you sniff inside a gas can or exhaust fuel?

 

Purchased as certified pre-owned in 2009 and I'm only owner since - so I presume the cats still there.


The smell is standing at the gas pump smell (raw). It doesn't seem to smell at startup/initial rest. As soon as I start driving and come to the first rest/idle I smell it - seems to get progressively worse at each stop.


I tried revving in neutral for extended periods of time to see if the smell went away (similar to driving) - and it didn't - so apparently only happens while in drive (maybe, unless there is another reason for that).


Checked garage again and all parking lots today - no gas.


It's freaking me out - I don't need a car-b-que although the mechanic claims there is no risk for that based upon their inspection.

 

What about cabin air filter? when was the last time you replaced that? could it be contaminated with the smell and overworked when it heats up and the smell returns? That is the only thing I can think of because you said you closed seals. Gas is a really strong smell, and it could be on any of the surfaces of your engine.

 

Yes, the tech replaced it thinking the same thing. Didn't do the trick unfortunately.

 

The fuel pressure regulator seems to be a common theme for the cause of a fuel smell in other Lexus models Does anyone know if the fuel pressure regulator would have to be tampered with (or is in close proximity) during replacement of the intake manifold gasket and valve cover gaskets?


I'm curious if the fuel pressure regulator was incidentally compromised during recent work - if not - perhaps this is all just an eerie coincidence.

 

Raw fuel is definitively leaking somewhere... You don't smell it on the road BC your car is rolling.

 

Off to the dealership to see what they say. My mechanic caught a whiff today and the smell is coming from the area of the left side gas pressure regulator. Of course its possible that something did not seat properly when they put the engine back together after replacing the valve gaskets, but he doesn't think that's the case since there is no visible gasoline at all - just vapor. The pressure regulator gaskets were replaced by Lexus as part of the recall - hopefully its a defect in their parts/labor and its under warranty. And hopefully I don't explode on the way out to the dealer 25 miles away!

 

There's no risk, don't worry... Car engineers are not that dumb! Hopefully that will solve your issue.