petrol in oil

Post by **minor-rich** » Fri Aug 29, 2008 8:38 pm

i am posting this for my uncle as he dosent have a computer.he owns a 1968 f reg morris 1000 ex police car.he says that he can smell petrol in the engine oil.he drained the oil and there was a strong smell of petrol.when the car is first started it is fine,as it gets hot it belts out white smoke.hes renewed the head gasket and some hoses i dont know which ones.he told me the that the float was very slightly bent so he straightened it.can anyone help please?

Post by **PAULJ** » Fri Aug 29, 2008 10:06 pm

Sounds like he may have upset the float hight and is flooding the engine. If too much petrol is let in to the cylinder it will wash the boar and pass the rings this will also cause wear in the boars and dillute the oil. This is not good

Post by **Leo** » Fri Aug 29, 2008 11:04 pm

By any chance has it had a mechanical petrol pump fitted?

Could be remotely possible being a police car

Leo

Post by **Kevin** » Fri Aug 29, 2008 11:06 pm

By any chance has it had a mechanical petrol pump fitted?

Thats got my attention Leo what difference would that make.

Post by **moggyminor16** » Fri Aug 29, 2008 11:07 pm

and mine

Post by **bigginger** » Sat Aug 30, 2008 12:08 am

Beats me - do tell, Leo

Post by **10852sm** » Sat Aug 30, 2008 5:17 am

Presuming Leo means a cam driven pump, maybe an internal leak could put petrol into the oil.

Post by **Packedup** » Sat Aug 30, 2008 8:20 am

Kevin wrote:
By any chance has it had a mechanical petrol pump fitted?
Thats got my attention Leo what difference would that make.

As alluded to, if the diaphragm lets go petrol can leak into the sump pretty easily as the diaphragm is the only seal between pump and engine.

Post by **bmcecosse** » Sat Aug 30, 2008 10:12 am

Yes - it can happen with Mini engines - mechanical pump leaks petrol into the engine oil, destroys the engine/gearbox/diff - and has been known to explode!
But all old oil smells a bit of 'petrol' - so it's likely as said above that it's running way too rich and has washed the bores - probably causing lots of wear if it's been going on for a while.

Post by **PAULJ** » Sat Aug 30, 2008 10:38 pm

If the diaphragm split on the cam driven pump would the engine still run?

Post by **bigginger** » Sat Aug 30, 2008 11:17 pm

Post by **Packedup** » Sun Aug 31, 2008 12:42 am

Define split. It's possible to have a small tear and still have some fuel make it to the carb, although you'd almost certainly notice a drop in power through fuel starvation. If you think about it, a small hole will mean a drop but not toal loss of pressure, and that drop will be from fuel passing through the hole rather than the outlet. Have a guess where the fuel not making it to the carb will be going..

Post by **bmcecosse** » Sun Aug 31, 2008 5:29 am

Yes - it keeps going, for a while.

Post by **Leo** » Sun Aug 31, 2008 10:28 am

Yes, on cam driven petrol pumps if the diaphragm splits petrol can leak into the sump. I have only seen it twice over 40 years, usually an early sign is when the oil level appears to be getting higher on the dipstick.
Both case I have seen were on Austin Maxi's.
Whatever the cause, petrol in the oil will lead to early engine failure

Leo

Post by **minor-rich** » Wed Sep 03, 2008 7:51 pm

no it hasnt had a mechanical petrol pump fitted.thanks for the advice so far.

Post by **bmcecosse** » Wed Sep 03, 2008 10:08 pm

I would just change the oil and filter - and check for petrol flooding at the carb and that the choke is going right off and the jet is getting back home fully.

Post by **Luxobarge** » Wed Sep 03, 2008 10:18 pm

You sure it's petrol he can smell in the engine oil?

White smoke usually = coolant getting into the combustion chambers = head gasket popped.

Is it using coolant?

Is the oil level going up? If it isn't, then it's unlikely that anything much is getting into the oil surely.....

Post by **bmcecosse** » Wed Sep 03, 2008 10:24 pm

White smoke for me is brake fluid being burned - through a leaky servo. So - if the car has a servo and the fluid level is going down ......

Post by **Luxobarge** » Wed Sep 03, 2008 10:26 pm

bmcecosse wrote:White smoke for me is brake fluid being burned - through a leaky servo. So - if the car has a servo and the fluid level is going down ......

Good thought - I was just thinking of something that might only smoke when hot though.....

We need to know what levels are going up or down!

If there was enough petrol in the oil to smell it clearly, then I'd imagine that the increase in level would be noticeable. Not convinced this is the fault TBH.

Post by **bmcecosse** » Wed Sep 03, 2008 10:40 pm

Servo white smoke shows as puff when brakes are applied - my mates MGB was doing this (I was following) and when I asked him if his brake fluid seemed to be going down his answer was "funny you should ask that". He removed the servo and it had brake fluid inside - now he has no servo, no white smoke - and is perfectly happy with his brakes!