Pretty sure I have diesel contamination in my oil. To be honest I haven't checked the level for a few thousand miles until just now and it's well above the high line. It was definitely at the correct level before.

 

My DPF regen has been upset lately after it got interrupted a couple of times and as a result it's been doing regens way too often which I probably will need to take it to dealer to sort out somehow. I suspect it's related, I seem to remember reading something along these lines on here about it?

You need to do a long hard extended run to burn it off. 

To "snowathlete" - You are absolutely right. A lot of "DPF"-Regenerations can (but some times - do not) add the Diesel in the Motor Oil. Change the Motor Oil as soon as possible. Do you have the "Eco Software" Update, installed on the car "ECU"? How many Kilometers do you travel between two "DPF"-Regenerations? In the City or Highway?

 

To "Shaunieboy" - What does it mean: Long/Hard/Extended? Please, give the example..

Edited 2 April, 20197 yr by tuningmania

Get the oil up to a high operating temperature (90 - 105 for our diesels) for an extended period of time and the diesel will evaporate off. How long depends on the amount of diesel in there. Obviously if you're a serious amount above the max line you're definitely best off changing oil but if it's a few mm caused by multiple failed regens over a short period of time, do some long hard driving and it will burn off. 

 

Watch this;

 

 

Diesel has a boiling point above 180 *C - getting the engine oil hot isn't going to cause diesel dissolved in it to boil off.

 

If the oil level is significantly above normal due to fuel dilution you need to do an oil change.

1 minute ago, chimaera said:

Diesel has a boiling point above 180 *C - getting the engine oil hot isn't going to cause diesel dissolved in it to boil off.

 

If the oil level is significantly above normal due to fuel dilution you need to do an oil change.

Does it need to be boiling to evaporate off though? I've no qualifications in science but water starts to evaporate much below its boiling point so is diesel different?

 

Not to doubt your logic but John is a pretty respected channel and he is himself an engineer. I would happily stand to be corrected though.

 

 

A small amount might evaporate off under the right conditions: your point on water is correct. Strictly speaking, the boiling point is the temperature/pressure point at which the substance cannot exist as a liquid and all of it will evaporate off.

 

Below the boiling point, evaporation can occur, depending on a few factors. Temperature is one, high means more evaporation. The other is how much of the substance is present in the gas phase: on a very humid day, water won't evaporate off nearly as quickly as it would on a dry day because there's a lot more water vapour in the atmosphere. Likewise, in the crank case of a car engine, there's already a lot of oil and fuel vapour in there so it'll act against the fuel trying to evaporate out of the oil.

 

So, it's possible for fuel to evaporate off from the oil under sustained high temperature running, but I'd question the wisdom of running an engine with diluted lubricating oil hard enough for long enough to get rid of the fuel. An oil change is not terribly expensive for the peace of mind it brings.

 

This of course doesn't solve the OP's problem of fuel getting into the oil in the first place. Either they modify their driving style/patterns to allow the car to finish regeneration most of the time, or maybe it's time to look at whether a diesel car is the best option for them. VAG DPF gets good reviews around here and would help to plan drives around a potential regen.

 

A word of caution, Skoda have issued a technical bulletin to dealers about this issue: basically if a car comes in with a dead DPF and evidence of fuel dilution of the oil there's no goodwill on offer and the owner will be on the hook for the full cost of any repairs. If the orange DPF warning light comes on, it's time to go for a long hard-ish drive to let it regen; waiting until the red one comes on will be expensive.

Clearly the car needs a run to ensure the DPF is regenerated - however I think it needs an oil change NOW. Diesel is a poor lubricator and you could firstly destroy the turbo, next the cam shaft (especially the PD lobes) followed by the engine. Diesel doesn't really evaporate under normal engine running conditions.

 

The 2.0 pd has a poor DPF implementation.

 

The other potential issue, especially if the turbo is starting to fail or engine is worn, is engine run-away (aka boom) if the engine starts to run on the diesel in the sump.

Edited 2 April, 20197 yr by bigjohn

At how many places do oil and diesel paths meet to swap bodily fluids?

 

 

 

 

On 02/04/2019 at 21:37, bigjohn said:

if the engine starts to run on the diesel in the sump.

 

Isnt it oil getting into the intake that causes scavenging?

1 hour ago, lichfielddriver said:

 

Isnt it oil getting into the intake that causes scavenging?

 

Yes - after the sump oil been poluted with diesel and then injected back into the intake via turbo seals.

 

If engine is really worn then it can run oil(&diesel) blowing back up past the rings (Zafira diesels well know for this!)

 

The Superb I 2.0 pd 8v diesel had a very poor DPF implementation and had oil pump/balance module drive issues.

 

On the Superb I none of the 1.9pd's had DPFs or the balance module. Some of the 1.9's fitted to the mkII did have DPfs though- I think just the 1.9 Greenline.

 

 

Edited 16 April, 20197 yr by bigjohn

Runaway happens because the turbo seals have failed and allow the oil supply to the bearings to enter the intake tract. Overfilled engine oil, or oil that has been contaminated with diesel won't cause it.

You need to change the oil now, as in the next few days, or stop using the car.

 

I had this issue, a leaky injector was diluting the engine oil with diesel, increasing the oil level above the max line on the dipstick.

 

The turbo failed very, very shortly afterwards. It relies on good quality oil for its lubrication. Skoda changed the turbo, without properly fixing the leak, which then quickly killed the second turbo.

 

Google 'bore wash' too.

 

It's takes an awful lot of failed DPF regens to notice an increase in the engine oil level, you should have seen the orange DPF long before now if this issue is purely down to an inoperative DPF. There is no red DPF light. You'll get the orange DPF light, which if not cleared will be followed by the DPF light plus engine management light (EML) and limp-home mode.

 

Don't ignore this issue, it needs attention sooner rather than later.

23 minutes ago, chimaera said:

Runaway happens because the turbo seals have failed and allow the oil supply to the bearings to enter the intake tract. Overfilled engine oil, or oil that has been contaminated with diesel won't cause it.

 

Depends on how much oil mists - contamination with diesel seems to make it worse. It may also be the fact that diesel contamination eventually destroys the turbo bearings and then damages the seals. Most bad ones I've seen have had diesel contamination. On some cars it is becasue the engine sump has become way overfilled because of the diesel topup!

Edited 16 April, 20197 yr by bigjohn

2 minutes ago, silver1011 said:

 

 

Google 'bore wash' too.

 

 

 

Indeed diesel is a poor lubricator.

 

 

 

Non-turbo diesels dont runaway then?

On 17/04/2019 at 13:40, lichfielddriver said:

Non-turbo diesels dont runaway then?

 

I can't remember the last time I saw a non turbo diesel - possibly a friends Ibiza 1.9 sdi

 

 

45 minutes ago, bigjohn said:

 

I can't remember the last time I saw a non turbo diesel - possibly a friends Ibiza 1.9 sdi

 

 

 

About 10000 2.5di transits? 

1 hour ago, lichfielddriver said:

 

About 10000 2.5di transits? 

 

Not for the likes of me 

Edited 18 April, 20197 yr by bigjohn

 

On 16/04/2019 at 22:03, bigjohn said:

 

Indeed diesel is a poor lubricator.

 

 

 

 

It will of given the engine a good clean from the inside though