Omega Owners Forum

Omega Help Area => Omega General Help => Topic started by: JamesV6CDX on 04 January 2007, 21:31:52

Title: Answer to the mystery of the disappearing petrol!
Post by: JamesV6CDX on 04 January 2007, 21:31:52
I think I may have solved it. Well, not solved it, but identified it.

I bodged the exhaust today just to stop the blow - I did another test, the cardiff to barry run, and I worked out the MPG to be 19.2 instead of about 16.5. MID was reading 26.4, which is about what I would expect to get on that run.

So that's a couple of MPG improvement. After I Filled it back to the top again, and got back... I noticed a puddle behind the back wheel. So I climbed under the car with the torch to investigate, and it was pretty clear by the smell that the puddle was petrol.

Looking under the car, I could see petrol, running ALL down the front of the tank, and dripping onto the floor at quite a hefty rate. I reckon at least 1 litre came out since it's been parked.

I'd like to sort the problem though, any ideas? And... silly question...   I take it this is why I've been "using" so much petrol after filling the tank!!
Title: Re: Answer to the mystery of the disappearing petr
Post by: MartinP on 04 January 2007, 21:43:47
If you want to replace the tank, Ive got one already removed, only needs a cap  ;)
Title: Re: Answer to the mystery of the disappearing petr
Post by: TheBoy on 04 January 2007, 21:43:53
Quote
I think I may have solved it. Well, not solved it, but identified it.

I bodged the exhaust today just to stop the blow - I did another test, the cardiff to barry run, and I worked out the MPG to be 19.2 instead of about 16.5. MID was reading 26.4, which is about what I would expect to get on that run.

So that's a couple of MPG improvement. After I Filled it back to the top again, and got back... I noticed a puddle behind the back wheel. So I climbed under the car with the torch to investigate, and it was pretty clear by the smell that the puddle was petrol.

Looking under the car, I could see petrol, running ALL down the front of the tank, and dripping onto the floor at quite a hefty rate. I reckon at least 1 litre came out since it's been parked.

I'd like to sort the problem though, any ideas? And... silly question...   I take it this is why I've been "using" so much petrol after filling the tank!!
So MID is reading MPG you would expect, but petrol tank emptying quicker?  I think MID is probably fairly accurate...

Dunno about leak, you just have to locate. Possible hose between tank and fuel filter?
Title: Re: Answer to the mystery of the disappearing petr
Post by: JamesV6CDX on 04 January 2007, 21:47:11
In my experience, MID always reads about 2 too generous, giving me an MPG of 24.3, which is exactly what I would expect. The engine is actually running lovely, and since exhaust bodge doesn't feel rich at all, so I reckon this leak is to blame.

I could just half fill the tank ;D
Title: Re: Answer to the mystery of the disappearing petr
Post by: TheBoy on 04 January 2007, 21:49:42
Quote
I could just half fill the tank ;D
Depends if its a hole in tank, or hole in pipes...
Title: Re: Answer to the mystery of the disappearing petr
Post by: Marks DTM Calib on 04 January 2007, 21:50:09
First off.....remove the inspection cover in the boot area (under the carpet) and check the level plate seal....

Thought the exhaust might be buggering up the mixture.....
Title: Re: Answer to the mystery of the disappearing petr
Post by: JamesV6CDX on 04 January 2007, 21:52:31
Cheers matey, I'll do that in the morning....
Title: Re: Answer to the mystery of the disappearing petr
Post by: Jay on 04 January 2007, 23:57:23
Your wasting petrol by filling the tank right to the top anyway, better to half fill it, ur not carrying all that unnecceary wieght around with u then!
Title: Re: Answer to the mystery of the disappearing petr
Post by: JamesV6CDX on 05 January 2007, 01:49:37
Carrying an additional 30 litres for such a powerful car would make a negligable difference and probably not noticable for fuel economy.

There is a differnent issue causing the excissive need for filling up

It's most likely the leak described in this thread.
Title: Re: Answer to the mystery of the disappearing petr
Post by: Glenn on 05 January 2007, 08:45:19
As Marks says, check under the inspection cover in the boot, I had exactly the same problem, turned out to be leaking from the plate which carries the fuel level sensor etc, just appeared to be loose but a good clean up won't do it any harm.
Title: Re: Answer to the mystery of the disappearing petr
Post by: nixoro on 05 January 2007, 10:54:24
Isn't there an overfill pressure release valve thingy somewhere near the top perhaps it knackered just a thought as mine does exactly the same when full up, so I tend not to fill it right to top lately.

Also noticed I loose petrol if its parked on a slant so try avoiding this aswell, not ideal but works till I can get it sorted.

Title: Re: Answer to the mystery of the disappearing petr
Post by: tunnie on 05 January 2007, 11:01:29
i think i heard of this kind of leak before on the other site, only affected it when brim full.

Try another test.... get the tank level to 1/4 then give it a run and see what the mpg is and check for leaks!  :y