Oil smells of petrol

[Pooh]

I checked the oil in my 400SE today and it smells of petrol, I have been suspicious that it is running a bit rich(black exhaust, smells rich/fumey)so this presumably confirms it.
The question is what could cause it to run rich and should I still be driving it?
The oil was changed less than 1000 miles ago.
Thanks
Robert.

[Boosted LS1]

Stuck injector? Sort out the problem before you bore wash the rings ie, don't drive.

[RussWood]

Has the oil level been rising - or in thecase of a TV not sinking as rapidly?

It may just be fumes that are blowing pat the rings, smelling of petrol because it's running rich.

But worth investigating in caseany harm is being done.

Russ

[Guillotine]

absolutely,

change the oil before driving!!!

[350zwelgje]

The temperature sensor is notorious for malfunctioning. On my RV8 it was so much overfueling due to this, that it wouldn`t run! Perhaps worth a check.
Can be tested by shorting the lead to this sensor (ECU signal for hot engine and creating a normal/lean mixture).

Rob

[Pooh]

Thanks guys, the oil level is falling rather than rising and I have changed the engine temperature sensor, the smell is not very strong but I have a poor sense of smell so that may not be much of a guide.
I went and had another sniff, it is stronger than I thought so now I have to track down the cause.

Edited by Pooh on Thursday 15th October 21:03

[Pooh]

Boosted LS1 said:

Stuck injector? Sort out the problem before you bore wash the rings ie, don't drive.

Is there any way of telling if one of the injectors is stuck and if so which one it is?

[Boosted LS1]

Yes, if you lift the rail you should see the dodgy injector pissing out fuel. Or remove the plugs and see what happens if the ignition's on. It may pump fuel into a cylinder which will stink. Or if you leave the rail in place and start the engine you may find one very wet misfiring spark plug. I've heard of oil levels in the sump rising when it's really bad. The exhaust pipes must stink of petrol if in injector stays open.

[Pooh]

Boosted LS1 said:

Yes, if you lift the rail you should see the dodgy injector pissing out fuel. Or remove the plugs and see what happens if the ignition's on. It may pump fuel into a cylinder which will stink. Or if you leave the rail in place and start the engine you may find one very wet misfiring spark plug. I've heard of oil levels in the sump rising when it's really bad. The exhaust pipes must stink of petrol if in injector stays open.

Thanks

[Pooh]

I think the fuel pressure regulator may be the problem, the fuel hoses were replaced by the previous owner and it looks to me as though the hoses might be connected the wrong way round.


The braided hose going in the bottom of the regulator goes to/from the fuel tank/pump and the black hose coming from the side goes to the fuel rail(I think).
Can anybody confirm that this is the wrong way round?
Also is it an adjustable regulator? Because it looks like one to me but I am no expert.
Thanks
Robert.

[Boosted LS1]

I think that looks fine. Fuel should enter at the side and return to the tank from underneath the regulator. It's an adjustable regulator, remove the lock nuts and you'll be able to adjust pressure with a terminal screwdriver. I wouldn't recommend making any adjustments though as that'll effect pressure across the whole rev range and you need to establish what pressure you have in the first place.

[Byker28i]

Pooh said:

Thanks guys, the oil level is falling rather than rising and I have changed the engine temperature sensor, the smell is not very strong but I have a poor sense of smell so that may not be much of a guide.
I went and had another sniff, it is stronger than I thought so now I have to track down the cause.

Honestly, use a woman. They have a much better sense of smell than men (so said the gas man when we had a leak and I couldn't smell it).

[Pooh]

Byker28i said:

Pooh said:

Thanks guys, the oil level is falling rather than rising and I have changed the engine temperature sensor, the smell is not very strong but I have a poor sense of smell so that may not be much of a guide.
I went and had another sniff, it is stronger than I thought so now I have to track down the cause.

Honestly, use a woman. They have a much better sense of smell than men (so said the gas man when we had a leak and I couldn't smell it).

I alredy did, I went to my wife and asked her to come and sniff my engine, she did and could smell petrol.

[cloggy]

Pooh said:

Byker28i said:

Pooh said:

Thanks guys, the oil level is falling rather than rising and I have changed the engine temperature sensor, the smell is not very strong but I have a poor sense of smell so that may not be much of a guide.
I went and had another sniff, it is stronger than I thought so now I have to track down the cause.

Honestly, use a woman. They have a much better sense of smell than men (so said the gas man when we had a leak and I couldn't smell it).

I alredy did, I went to my wife and asked her to come and sniff my engine, she did and could smell petrol.

Sniff my engine yeah.

[Pooh]

Boosted LS1 said:

I think that looks fine. Fuel should enter at the side and return to the tank from underneath the regulator. It's an adjustable regulator, remove the lock nuts and you'll be able to adjust pressure with a terminal screwdriver. I wouldn't recommend making any adjustments though as that'll effect pressure across the whole rev range and you need to establish what pressure you have in the first place.

OK thanks, I am used to relief valves that take pressure in the bottom and relieve out the side.
Is it possible that the regulator is stuck or just set too high?
When I get a chance I will remove the spark plugs and see how they look.

[350zwelgje]

Fuel pressure set too high could absolutely be an issue, as injectors can weep due to being overpressurised. And in general too much fuel will be injected as well.
Resetting it could perhaps solve your problem.

From the picture it looks like I have the same rising rate FPR (FSE). It needs regular `attention` as the setting changes over time. Due to this I haven`t experienced heavy overfuelling but it is possible. I even left the pressure gauge attached after initial setting it up, so I can monitor and adjust as required which I do a lot....

Hopefully you are on the right track to solve it with this.

Rob

[Pooh]

350zwelgje said:

Fuel pressure set too high could absolutely be an issue, as injectors can weep due to being overpressurised. And in general too much fuel will be injected as well.
Resetting it could perhaps solve your problem.

From the picture it looks like I have the same rising rate FPR (FSE). It needs regular `attention` as the setting changes over time. Due to this I haven`t experienced heavy overfuelling but it is possible. I even left the pressure gauge attached after initial setting it up, so I can monitor and adjust as required which I do a lot....

Hopefully you are on the right track to solve it with this.

Rob

Thanks, I think I need to get a fuel pressure gauge and set the regulator up properly.