Fuel in oil

[jimmy156]

Car been diagnosed with a faulty HPFP and has fuel showing in the oil.

Part needs to be ordered and they can’t fit me in until next Friday. Normally I do about 400 miles a week. Should I minimise my driving? Avoid completely? Or will it be alright. Car is a turbo petrol if that makes a difference (golf GTi)

[bimsb6]

What does the dealer think?

[E63eeeeee...]

Aiui the problem with fuel in the oil is it stops the oil protecting your engine properly, so it will presumably depend on the level. Iirc 3% was the limit (but was a diesel so may be different for petrol), how long you're planning on keeping the car etc. Quick oil change would probably minimise the risk of any damage for now.

[BananaFama]

I wouldn't use at all with petrol thinning out your engine oil ,could go bang !

[Miserablegit]

If it is a faulty HPFP then, at a guess, the fuel is getting into the oil because the HPFP is overfuelling and the unburnt fuel is running down the bores into the sump, stripping the oil off parts as it goes.
If this s the case then :
A) it gets worse every time you run the car
B) depending on how long it has been going on the lubrication properties of your oil are going to be significantly reduced leading to premature wear.

Would I drive it?
Nope.

[jimmy156]

Garage opinion was “don’t drive too far but it should be okay” but it’s not their car is it

I tend to keep my cars a while, and just about to spend a bunch doing the HPFP, so will be keeping for a while longer

Dont want to do an oil change to dump it again after the fix. The oil is only a few weeks old anyway.

[jimmy156]

Miserablegit said:

If it is a faulty HPFP then, at a guess, the fuel is getting into the oil because the HPFP is overfuelling and the unburnt fuel is running down the bores into the sump, stripping the oil off parts as it goes.
If this s the case then :
A) it gets worse every time you run the car
B) depending on how long it has been going on the lubrication properties of your oil are going to be significantly reduced leading to premature wear.

Would I drive it?
Nope.

This was my concern. Car is running rich, so this almost certainly the case… i want a good few years use out of it yet, so maybe wise to be cautious!

[E63eeeeee...]

jimmy156 said:

Garage opinion was “don’t drive too far but it should be okay” but it’s not their car is it

I tend to keep my cars a while, and just about to spend a bunch doing the HPFP, so will be keeping for a while longer

Dont want to do an oil change to dump it again after the fix. The oil is only a few weeks old anyway.

If they've found noticeable fuel in oil that's only a few weeks old, I'd definitely not be using it.

It's likely to be fine, think about how few cars are actually scrapped because of engine wear, but if it's that bad I'd find something else to drive for a couple of weeks.

[MDMA .]

Was it showing a fault code? MK5 and MK6 GTI’s normally suffer from a faulty/open injector, which causes the excessive fuel in the oil. The pumps are usually ok, unless it’s had a previous upgrade and they didn’t replace the seal. The original seal can get dislodged when replaced.

[jimmy156]

MDMA . said:

Was it showing a fault code? MK5 and MK6 GTI’s normally suffer from a faulty/open injector, which causes the excessive fuel in the oil. The pumps are usually ok, unless it’s had a previous upgrade and they didn’t replace the seal. The original seal can get dislodged when replaced.

Yes two, one for low boost pressure and one for being rich on bank 1 (presumably 1of1!)

I am aware of injector issues on golfs, but I am assuming the garage know more than me. They did mention that it could also be the injectors, but they thought the HPFP more likely.

[anonymous-user]

OP,

Do you have breakdown insurance?

[TarquinMX5]

jimmy156 said:

Garage opinion was “don’t drive too far but it should be okay” but it’s not their car is it

I tend to keep my cars a while, and just about to spend a bunch doing the HPFP, so will be keeping for a while longer

Dont want to do an oil change to dump it again after the fix. The oil is only a few weeks old anyway.

'Should' be okay? That sounds like a guess.

Without knowing the dilution figures it can be nothing more than guesswork and it's impossible for anybody on here to know whether any long-term damage might be caused. If it was mine, I wouldn't drive it.

Ask the garage if they're prepared to support their 'advice' with the offer of a written guarantee to replace the engine with a brand-new one should there be any problems in the next five years if you follow their advice . I wonder what they'd say?

[Twolane]

You won't be doing the cat converter any favours either