Turbo oil leak?

[tref]

Gentlefolk,

Took the Turbo out this morning, and noticed oil presure was down a little... after stopping for petrol after five miles, smoke could be seen out of the back of the car. I stopped and had a look, and the smoke was from under the bonnet, not out of the exhaust. So... I guessed I had an oil leak, probably onto the turbo or its associated pipes where it was burning off. I turned round and have put the car away until I can look at it.

So... there were drips of oil on the drive way on the left hand side of the car. Oil pressure is down by about 1 - 1.5 Bar. So I am assuming I have a high pressure side oil leak. As far as I can think, the only thing on that side of the engine likely to leak oil is the turbo feed. I would assume the turbo oil return should not cause the drop in oil pressure.

I am guessing I will have to take the inlet manifold off as a minimum to get to it, how-ever, first, does any-one have any other ideas what it could be? and assuming it is the Turbo oil feed, anything any-one can think of that I should know?

1986 220 '44 Turbo by the way. A red one.

Best regards,

Tref.

 

[robwright]

Yes mate to get to the turbo the inlet manifold will have to come off. Not a job for the faint hearted. Actually having said that there is nothing complicated it's just very involved and can be a bit daunting when you see that half of your engine has migrated from the engine bay to the workshop floor. I did a turbo swap. There were quite a few complications though and it ended up taking me 6 days on and off. []

 

[TTM]

It shouldn't be necessary to remove the turbo if it's the oil feed line, however if the turbo has to come out then it's easy to take it off with the exhaust pipe on.
The two lower bolts that hold it onto the engine mount are easily accessible from below with the right tools.

 

[tref]

I guess the big question for me at the moment is where the oil feed pipe is... and if it is possible to get to it from under the car without removing the inlet manifold... Otherwise it is off to get some new inlet manifold gaskets and make up some blanking plates to keep crap out once the manifold is removed.

 

[robwright]

Actually if memory serves me correct mate the turbo bolts directly onto it's own oil feed on the engine and seals with an o ring. The oil return is via a 21mm (or could be bigger) banjo connector on the side of the turbo. If you ask me the chances of it being either of those are quite remote especially the feed line. The return lines is a steel pipe IIRC. Could be wrong I have slept since changing the turbo and am trying to blank the experience from my mind.

 

[TTM]

The oil feed pipe to the turbo can be seen somehow behind the thermo probe for the turbo cooling pump. It's a braided hose.
Two bolts hold it onto the turbo center section. It might be possible to remove these two bolts, but you would be extremely talented if you managed to remove the other side that connects to the balance shaft housing, without taking off the intake manifold! To make things worse the supporting brackets for the intake manifold on the turbo side are linked with a heatshield that just covers the bolt of the oil feed line.

 

[tref]

ORIGINAL: robwright

Actually if memory serves me correct mate the turbo bolts directly onto it's own oil feed on the engine...

That... was my worst nightmare (and I haven't slept on it yet!)

 

[tref]

ORIGINAL: TTM

Two bolts hold it onto the turbo center section. It might be possible to remove these two bolts, but you would be extremely talented if you managed to remove the other side that connects to the balance shaft housing, without taking off the intake manifold! To make things worse the supporting brackets for the intake manifold on the turbo side are linked with a heatshield that just covers the bolt of the oil feed line.

Hmmm... sounds like taking the manifold makes sense then. I am currently wondering if I can take the inlet manifold off, and crank the engine sufficiently to build up oil pressure and see exactly where it is leaking, given I suspect that all traces will have burnt off (given the amount of smoke generated!)

 

[robwright]

There is a diagram of the oil feed and return lines here on clark's. The oil feed is bolted directly onto the balance shaft housing.

http://www.clarks-garage.com/pdf-manual/lube-11.pdf

 

[TTM]

You can build oil pressure without starting the engine. Either remove the DME relay or plug off the line from the ignition coil to the distributor while you crank it.

 

[tref]

OK... I now have the inlet manifold off... and I'm not finding what I expected!

 

[tref]

OK... Now I know that I have successfully loaded the image!

What I assume to be the oil feed to the turbo is quite clear... and clean. I was expecting to see it dripping with oil. I am assuming it is the one bolted to the top of the turbo, with a braided secion, and then wends its way to the balance shaft housing the other side of the heat shield.
The pipe out the back of the turbo has obviously seen lots of oil - and it has puddled on the flange - so it does at least look like an external leak. There would also appear to be a fair bit of oil on the throttle body underside.
Unfortunately I haven't been able to build up sufficient oil pressure cranking the engine to show up the leak, and it doesn't obviously look like this feed pipe...
Any suggestions?
Oh... the oil filler tube is covered in oil too, but that looks like it has been there for some time.

Tref.

 

[TTM]

I'd say turbo seals are leaking exagerately + some bolts holding the turbo assembly on the exhaust pipes have got loose, letting oil out.

What grade of oil are you using and what is the mileage on the turbo?
Anything thinner than 15W50 on a high mile turbo is a big no-no in my opnion.

Clean the area with brake cleaner, top up the oil level, drive with no boost at all for a good hundred miles and check again if oil is dripping again.

 

[tref]

Would you not expect smoke from the exhaust if that were the case? there was no smoke from the exhaust. The car, and presumably the turbo is now up to 120k miles. As soon as I saw the problem I drove home off boost anyway, and still it was leaking oil.

Thanks for the suggestion of the brake cleaner - that is good for that type of thing is it?

I'm currently wondering if that section of the turbo get hot enough that no oil staining occurs, and tempted to take to oil pipe off and pressure test it before putting it all back together with new copper washers and gaskets...

Still any other suggestions gratefully received!

 

[TTM]

Cleaned an oil sump inside & out yesterday with brake cleaner, came out like new.

 

[944Turbo]

Is there an o ring on the dipstick? there is a pattern of oil around it on the brake master heat shield, and if there is any boost induced blowby on the rings the crankcase will pressurise forcing oil out of dipstick tube - I usually leave the filler cap relatively loose so any pressure can escape there - I also have a catch tank with a feed back into the inlet path.

Tony

 

[robwright]

Tony could you post a piccy of your catch tank arrangement. It is something I am very interested in doing on my turbo.

 

[tref]

Funnily enough, I thought the dipstick tube was loose when I undid it from the inlet manifold, and that was something I was going to look at, how-ever, I don't think it would explain the drop in oil pressure would it?

 

[sulzeruk]

The other thing that can happen Tref is leaky injectors as well. If the car has been running a bit rough, you can also be getting fuel dilution which would also thin the oil. Well worth having a smell of the oil and see if there is petrol in it. Also, see if the level has risen. I have seen this twice before in turbos so well worth a check!
Alasdair

 

[944Turbo]

ORIGINAL: robwright

Tony could you post a piccy of your catch tank arrangement.  It is something I am very interested in doing on my turbo.

It is hidden behind the PU just in front of the passenger side wheel arch liner with an access hole (with a bung) through the batwing to empty it. I do have some pics somewhere, catch tank is from Jon Mitchell and I was going to write up a document for installation - there is a handy bracket to mount it and the pipes just go where the standard ones do. I was not overly happy with my pipe run however as the headlight mech catches it occasionally. Also with standard airbox snorkel it is very tight to get pipes through to this location.
Tony