Oil in Intake manifold

[IRLGW]

I got a phone call this evening from a fellow 80series (97vx) owner somewhat distressed that his turbo had blown. Apparently he was driving along when the engine began revving out so he tried turning off the ignition but then had to stall it to stop. Worried that the traffic behind where going to pile into the back he looked in the rearview mirror only to see that the smoke cloud was so dense that the traffic had actually stopped becuase of zero visibility the mortification unfortunatley didn't stop there as he had to be towed home by a renualt van

The truck only has about 150k and he keeps it in pretty well serviced. This sounded surprising so I got him to get his mechanic to strip it out and inspect the fan. Reports came back that the turbo was actually fine but there was a lot of oil in the intake side of the inlet manifold.

I haven't spoken to the mechanic himself yet but he was having trouble understanding how the oil was in the manifold but didn't appear to have come from the turbo unit.

My first thought were perhaps something to do with the egr valve. I don't know if he is referring to the crossover pipe from the turbo or the actual intake manifold.

other than a damaged turbo seal is there anywhere else for the oil to enter the system or any other ideas....

 

[Towpack]

I can think of only 2 ways oil can get into the intake tract. Via the turbo and via the engine breather. The EGR valve lets exhaust gases in to mix with the intake air for emmission purposes. All turbo diesels will put some oil into the intake via the breather but not enough to cause the engine to run on unless it's suffering serious blow-by which would give other symptoms. IMO the only way enough oil could suddenly enter the intake in enough quantity to cause the engine to run on it is via a blown turbo seal. I would imagine it's possible to get a blown turbo oil seal without the turbo itself suffering catastrophic faliure so I would be sceptical of the mechanic's diagnosis that the turbo is sound. JMO

 

[IRLGW]

Thanks Towpack,

the mechanic rang me today but is adamant that the oil did not come from the turbo.... Apparently when he removed the egr there was a substantial amount of oil lying in that part of the manifold. For arguments sake, if oil didn't come through the turbo then is there another way that it could arrive here in large quantity? I also read on a post somewhere on an 80 series forum that a leaking front seal in the IP could cause the engine to run on as well but it wasn't conclusive- does anyone with exp of the IP know if this is a possibility?

 

[joinerman]

Yes the front seal went on my IP, fuel then leaked into the timing chest & down into the sump hence mixing with the oil, i was lucky & happened to check the oil level & it was about two inches higher than it should be, investigations tracked the problem down to the seal, as i say i was lucky & had no damage.

 

[Towpack]

Oil vapour/mist from the engine breather enters the inlet tract just after the air filter and is sucked through the turbo, blown through the inlet manifold and into the engine. This oil can collect at the EGR valve assemblies, especially if they have been blocked off, as they are sat slightly lower than the main air manifold that crosses over the top of the engine but, personally, I still don't see how this could be enough to make the engine run on. Running the engine with the breather pipe disconnected and fed into a container of some sort would eliminate the breather as the source.
Fuel getting into the sump from a leaking IP seal would obviously dilute and thin the oil, possibly to the extent where much more oil would be forced out through the engine breather system? A noticeable drop in oil pressure would be another symptom of this situation I would have thought.

 

[OG.]

Check the oil level. If its not high then it pretty much must be the turbo.

 

[IRLGW]

The 'oil' in the egr valve was reportedly very thin although the said oil level was reported to be just a bit below normal. The other factor is that the truck has been run on veg/kero for around two years so perhaps it could have caused damage to the IP seals. I spoke to the owner again last night and he said it had been running very lumpy for the last week or so. Thinking thatthe veg could be blocking the injectors the owner put about 40l of red in the tank and it was running on red when this happened....

Out of curiosity can the ip seal and turbo seal be replaced by a normal mechanic or do they require specialist tools? Also wondered if anyone had used the turbos that are going on ebay for £220-£250?

 

[joinerman]

Yes the seal can be done by a " normal mechanic " You will need a puller to remove a drive gear in the timing chest but my boy who's a " normal mechanic " simply made one up, the seal is around the size of a two pence piece & was less than a fiver but it's advisable to replace any gaskets & other seals while your in the timing chest.

 

[karl webster]

I heard bad reports regarding the cheap turbos on ebay. I would buy a genuine econd had one or hve the one you have reconed. That isnt pushing any parts glen just heard a couple of stories about them not lasting long at all.

 

[IRLGW]

I agree totally Karl but wanted to ask the question in case it came down to budget for the chap. He relies on the truck for work so if it was necessary for a quick cheap fix then it would or would not have been an option. I think it would fix your turbo quick but ultimately could wreck the engine I guess. The chap is extremely grateful for all the advice and I think his option is really to recon the turbo and IP seals while the opportunity has presented its-self...

 

[IRLGW]

Upon further inspection the mechanic is now convinced that the turbo was the problem and the seals have gone....therefore the owner wishes to recon the turbo so are there any recommended places to go or people to see re getting a cruiser turbo reconditioned? has anyone had, or heard of this problem before and what is the likely cost of a recon?

cheers

 

[OG.]

Turbo seal failure is not uncommon (had one fail on my Volvo car last year and on a previous car a few years back).
Try 'The Turbo Centre' near Wakefield.
http://www.turbocentreuk.co.uk/