Petrol Smell

[Nottingham Lad]

My 1995 LS400 Mk3 has developed a strong petrol smell over the last three weeks. It is noticeable when you walk round the car after it has been standing a couple of days.

It’s prominent in the boot and in the cabin. After driving for 20 miles or so it disappears but is back again a while after it has been parked.

My local MOT garage who is a good pal of mine has had it over his pit and up on the ramp. Nothing is amiss under the car although the fuel pipe runs under a false floor so is not visible under the central section. He pulled the boot lining out when I was there and the tank was exposed but all was well and no sign of a leak from the tank to the filler cap. After all the searching my pal could still smell it but his brother couldn’t and he said all it needed was a good run and suggested I got in. I sat in the passenger seat and we took off literally. The car has never gone so fast since I bought it. Both the brothers run big Mercs and drive like there’s no tomorrow. He suggested the cats could be clogged and needed a blast now and then. Next day it was smelling on the drive as usual.

I took the top cover off the engine today but I couldn’t smell or see anything.

Any suggestions please or is it a trip to the Lexus dealer?

[Steve ( West Mids )]

Only suggestion is that if it smells of petrol you should not drive it :(

[ROYT]

Keep looking, it's not a thing to ignore.

If fuel consumption rises, look for leaking injectors, any fuel lines rubbing where they

run along the body etc.,all the usual things

Is the fuel filler cap tight?

[Manc]

Dont have a cig while you think about it.....................and hope the kids on your estate are smart enough to avoid the quick giggle they might get from.......well you know..........

Is the filler cap ok? might be worth getting a new one, or new seal whatever the case may be...does yours hiss when opening it when the tank is nearly empty? this i was told is a sign of a crap seal that lets air in........which obviously can also let air out. but this would not cause a 'strong smell', just a whiff.

Is all the plastic casing in the filler cap housing ok? no cracks? all screws in place and tight?

Fuel also evaporates quickly, so it might be an idea to keep the boot lining out for a few days and put paper towels down near the filler pipe and check after parking up. A drop of fuel can stink for days so this is a reasonable plan.

Have someone with u when u next fill up, and if the boot lining is absent still, then might be worth him looking in boot as you fill up or vice-versa

How long did your mate look at it on the ramp? Maybe more time up there with starting and stopping engine would find the leak....

Good luck

[steveskeggy]

No, it should hiss when opening the fuel cap, if it doesnt then get another because thats where the smell is coming from.

It is true that in older cars that if the breather in the cap got clogged then it would hiss and it was time to get a new one, or drill a small hole in the old one!

However, modern cars are fitted with an OBD II fuel cap, which allows breathing both way.

The system either pressurises or applies a vacuum to the tank in order to check for leaks and if it detects even a tiny leak will iluminate the check engine light on the dash.

It may be worth getting a new cap anyway, but it would have to come from a Lexus dealer because different cars have different systems, so there isnt a generic cap that will do, dont be tempted by a cheap one off eBay unless its a genuine Lexus/Toyota one.

Meanwhile, you may want to check this:

http://www.planetsoarer.com/petrolsmell/petrolsmell.htm

I know its for a Soarer, but the cars are closely related, and although it may be different, the LS may still have the rubber hose in question. At worst it`ll only cost an hours work, at best you will find the cause.

Dont have a cig while you think about it.....................and hope the kids on your estate are smart enough to avoid the quick giggle they might get from.......well you know..........

Is the filler cap ok? might be worth getting a new one, or new seal whatever the case may be...does yours hiss when opening it when the tank is nearly empty? this i was told is a sign of a crap seal that lets air in........which obviously can also let air out. but this would not cause a 'strong smell', just a whiff.

Is all the plastic casing in the filler cap housing ok? no cracks? all screws in place and tight?

Fuel also evaporates quickly, so it might be an idea to keep the boot lining out for a few days and put paper towels down near the filler pipe and check after parking up. A drop of fuel can stink for days so this is a reasonable plan.

Have someone with u when u next fill up, and if the boot lining is absent still, then might be worth him looking in boot as you fill up or vice-versa

How long did your mate look at it on the ramp? Maybe more time up there with starting and stopping engine would find the leak....

Good luck

[Steve ( West Mids )]

OBD II fuel cap

I thought OBDII was computer software for access to faults etc via a reader.

[steveskeggy]

Possibly could have called it an OBD II Required-standard Cap, but thats a bit long winded...

OBDII is a system that covers a range of items and (sub) systems all around the car that basically report faults back to the onboard diagnostics computer, that then displays the fault as an illuminated lamp on the dash, and a readout from the OBDII conector.

The fuel cap is part of a system (I believe its called the EVAP system) that controls leaking of fuel vapour into the atmosphere, and is specifically designed and calibrated to work with the OBDII system that the car uses.

OBD II fuel cap

I thought OBDII was computer software for access to faults etc via a reader.

[Nottingham Lad]

Thanks for all your suggestions over the last couple of days.

Update: When I took it to my local man (in my first post) the journey had diluted the smell somewhat and it was therefore difficult to pinpoint. I rang him last Friday and asked him to call by on his way home having left the car closed and standing all day.

When he arrived he got in the cab and the smell of petrol was very apparent. He said it was a stale petrol smell and it was likely coming in from the boot. We opened the boot and the smell was bad but he said that is a fresh petrol smell.

We checked under the bonnet but there was no smell at all.

He said" Leave it with me mate, I'll pick it up on Tuesday or Wednesday and we'll pull the boot interior out and get to the bottom of it. "

So I hope to be able to post at the end of the week that it's all done and the answer was..............!

Thanks again for your interest will be back later in the week.

[Ruud]

Thanks for all your suggestions over the last couple of days.

Update: When I took it to my local man (in my first post) the journey had diluted the smell somewhat and it was therefore difficult to pinpoint. I rang him last Friday and asked him to call by on his way home having left the car closed and standing all day.

When he arrived he got in the cab and the smell of petrol was very apparent. He said it was a stale petrol smell and it was likely coming in from the boot. We opened the boot and the smell was bad but he said that is a fresh petrol smell.

We checked under the bonnet but there was no smell at all.

He said" Leave it with me mate, I'll pick it up on Tuesday or Wednesday and we'll pull the boot interior out and get to the bottom of it. "

So I hope to be able to post at the end of the week that it's all done and the answer was..............!

Thanks again for your interest will be back later in the week.

I have been following this post and I must admit that I have never come across any Ls smelling of petrol...however..

I'd check the breather pipes, it is quite possible that one somehow got lifted and ended up in the boot instead of under the car...

[Nottingham Lad]

I collected my LS400 late yesterday with the petrol leak believed fixed.

After they removed the tank they found a small area of corrosion round the outlet from the tank and this was dealt with. They removed the connection/s and the aluminium washers on the outlet were found to be in poor condition. They were replaced with copper ones as aluminium washers were not available. I had given them the number of Lexus Nottm but they were anxious to get on with it and didn’t trust the post? Not sure whether I am entirely happy with that.

As they explained, the smell will not disappear immediately and I assume there was probably some petrol about when the pipes were disconnected so there is still a smell of petrol in the car. It is definitely less in the cabin now but probably worse in the boot. The weather has been poor today but hopefully tomorrow I can remove the upholstery from the boot and see if I can see anything and then leave to boot open all day.

So, I don’t know whether it is cured or not yet but fingers crossed.

[Manc]

i wouldn't worry too much abvout the washers mate, they should have checked them after fitting anyway, cant see them doing all that work taking it out to just throw it back in without checking :shutit:

not even cowboys do that do they?

The smell should have gone by now, being the end of the month

Whats the latest?