7 replies to this topic

[DClarke1954]

Hi All,

 

Classic Mk3 Mini1275/HIF44 nothing too fancy I think.

I noticed yesterday that the inline fuel filter looked "empty".

As the engine was running I could see the little spurts of fuel entering on the input side.

I recently rebuilt the old SU pump with a NOS rebuild kit c.1975 MOD stores as it had been weeping fuel from the pump breather port.

I switched off and pulled the dipstick out.  All very clean (oil & filter change <150 miles ago) but my panicked brain convinced me I could smell "petrol".

Now the oil level isn't UP and I cannot see any "2-ring" trace of 20/50 surrounded by a ring of lighter petroleum distillates when I place the stick on a clean wad of white kitchen towel.

I have put a brand new pump on there this morning and removed the filter (which to be honest was pretty carp anyway).

Before I go chucking away nearly 5LTRS of fresh oil and filter is there a sure-fire home test for the presence of excess fuel in the sump oil?

I know petrol and oil are miscible and will mix quite well, but it may be that sump oil will always pick up a trace of petrol in the normal course of an engine's operation, I don't know.

 

Many thanks in advance.

 

D.

 

PS.   Yes, I know new oil & filter is cheaper than a new engine.

Edited by DClarke1954, 07 April 2025 - 02:25 PM.

[nicklouse]

Oil level rising.

 

oil smells like fuel.

https://youtu.be/w55...qPvbssAun-uSnpH

[imack]

Take a sample and try setting it alight with a match. Neat oil won't ignite easily. This is how we used to confirm the presence of petrol in diesel.

[DClarke1954]

Oil level rising.

 

oil smells like fuel.

https://youtu.be/w55...qPvbssAun-uSnpH

My sense of smell aint that great But I always thought petrol was a stronger smell.
Oil level is not rising on the dipstick as far as I can tell.
 

 

Take a sample and try setting it alight with a match. Neat oil won't ignite easily. This is how we used to confirm the presence of petrol in diesel.

I will do this, thanks. My BIL said the same thing, suck a sample out of the dipstick hole, put it in a tray and put  a match to it.   

[Ethel]

Some fuel will get by the pistons, it don't turn off on overrun like that new fangled injection m'larky.

 

Air visible in inline filters is also normal, it's only a few psi above atmospheric - as long as the pipe in 'n out are submerged it's probably a good thing. Damping out the squirts from the pump a bit for more constant pressure.

[68+86auto]

It will have a very strong smell of petrol when it's contaminated. It should also run rich but that does rely on accurate emissions testing before and after contamination.

[DClarke1954]

Update:

Thanks all for the useful and pragmatic advice you all imparted.

Today I pulled some engine oil out with a vacuum cleaner and a length of 6mm tubing

Dumping it into a glass bowl I tried to light it with a piezo-electric gas lighter (as I use on lighting my woodburner).

No "flash-flame" no burn-off.  So I guess it's all OK.

I will keep an eye on the oil level, just in case though.

Maybe the lack of fuel in the filter was a direct result of the inlet pipe having collapsed under the jubilee clip inside the fuel-line tubing and NOT the pump having failed and dumping the fuel into the sump.

 

We live to fight another day it seems. 

Jeez I love this forum.

 

 

 

 

[alpder]

Just a thought...

When it comes to fuel components, brand new ones should at least be manufactured from something ethanol resistant. Whereas that may not have been part of the manufacturing spec for NOS items. If a flexible part isn't compatible with ethanol it'll seem to work fine at first, but give it a few months and it is likely to become porous or even split.

NOS is often the best choice for many car components, but not necessarily for rubbery fuel bits.