140/603.971 Turbos

[JMH]

After reading all the reply posts on this site to my previous posts about the dreaded 603.971 oil burnin' sob that I now own....... I heeded Hatterasguy's feedback to pull the crossover pipe from the turbo to the intake manifold. I did that this past Saturday.

Gee whiz, that thing was coated, bathed, caked with black tarry oil. I then pulled the rubber ductwork from the air filter to the turbo off. There was about a half teaspoon of oil on the bottom curve of the turbo air intake. As I looked into the turbo from above, it looked like the EGR was cooking the oil as it came up from the turbo and had a hardened oilcake surrounding the EGR entry to the turbo output.

So now I have a question, a theory and a statement......

Question:
Where would anyone recommend getting a turbo repair/rebuild kit for a DIY'er... or just a rebuilt turbo for reasonable $'s????

Theory:
At the increasing rate of oil burn, I suspect that at some point, the amount of oil coming into a given cylinder could be enough to create an engine-lock on the oil in the combustion chamber......that might not be compressible and thus "something's gotta give" a la the rods?

Statement:
My 603.971 starts right up even on colder mornings (lowest so far in the high 20's). When I bought it, it had about 2 bad glow plugs. Even then, it started right up. It has good acceleration from a deadstop or at highway cruise speeds. Except for the greyish plume left behind/the quantity of oil burned, it all seems good...... so maybe the Turbo's are the culprit on these much maligned engines.... there is too much that seems right. I also cannot correlate how the engine burning oil would be commensurate with the lower end of the engine going bad....... main and rod bearings don't burnoil do they?

Any feedback or answers anyone has are sure welcomed, especially where I can get those parts!

Thanks,
JMH

IIRC, most of these rod-benders bend the rods because the #1 cylinder (primarily) becomes ovaled due to the increased stroke of the engine and the weak connecting rod design, thus making it impossible for the rings to seal the cylinder. The combustion gasses escape into the crank case, and oily vapor starts to pour out of the crankcase vent (on top of the valve cover), which returns to the intake pre-turbo. This oily vapor then mixes with soot from the EGR and creates some nasty stuff inside of the intake manifold and crossover pipe. Oil also gets past the oil control ring due to the out of round cylinder(s), thus bending the offending rod(s) even more. It's really a vicious cycle.

I've read a few threads where owners of these engines have replaced a turbo to try and control the oil consumption, but to no avail.

Before you replace your turbo, do a compression test on the engine.

[JMH]

Thanks for the reply. I do not recall reading this before. However, I think that when I had it in the shop back in September or October 2004, they checked the piston travel when the head was off (had the head machined, valve guides replaced, hydraulic lifters replaced). All pistons crowned at the top of the block. When they put it back together, it spec'd on compression and the leak down test was okay. So maybe I'll be a lucky one and the turbo is the culprit. I forgot to mention also in earlier posts that when I pulled the rubber duct work off of the turbo, I looked in the rubber ducting to see if there was a large amount of oil or oil residue in the rubber ductwork. There was a nominal amount. That ductwork looks like a bellows of sorts so there is ample room inside of it to trap oil. There wasn't much there. So I think that it is the turbo but I am going to take it back to the shop tonight and let them look at it and tell me where I'm losing the oil....... it is so voluminous an amount that I have to believe that it is the suction of the turbo that is pulling it from around it's seals. I mean that crossover pipe is really got alot of oil residue in there.

I think I am going to try the jug test of the vent pipe to see if it filles the jug with oil at highway speed. That would be the only way to really diagnose this properly is if that jug gets filled with oil from running down the highway at higher RPM's.

Thanks for posting back.

JMH

[Hatterasguy]

I don't know much about the turbo's for these engines mine hasn't broken yet! But I know rebuilt turbo's run in the $700 range if that helps, better then a new bottom end but not cheap.

A while back their was a good thread on these engines and another member had a theory that the egr would drop crap into the cylinders and cause the rods to bend. You are on the same tack with the oil. However I don't think oil would do it, the engine would just burn it and if so much was dumped into just one cylinder for example that it would not, you would have a nice skip. A diesel engine will skip just like a gas engine with a bad plug, you will know if a cylinder is not firing.

While you are at it clean the intake manifold out, Oldsouth figured out how to get rid of the egr on the newer 603's. If you bolt the crossover to the manifold they will sit perfectly upside down. Then fill them with kerosene and let it sit for a day or so.

[Brian Carlton]

Originally Posted by JMH

I think I am going to try the jug test of the vent pipe to see if it filles the jug with oil at highway speed. That would be the only way to really diagnose this properly is if that jug gets filled with oil from running down the highway at higher RPM's.

First, you already had a thread going about this. Why start another? Thread continuity on what was previously discussed and what was performed is vital to the success of the forum.

Second, the aforementioned test was suggested in the other thread. Without that test, you cannot determine if the oil in the turbo is due to the oil seals leaking or is simply oil from crankcase blowby. That test will tell you.
My recommendation is to leave the jug in place for at least 1000 miles. You must compare the amount of oil in the jug to previous data for oil consumption. If the amount in the jug closely matches the oil consumption, then you are wasting your time rebuilding the turbo.

[JMH]

Not sure about thread continuity. If I erred, my apologies. Hard to keep it straight late at night after a long day at the salt mine.

I pulled the vent tube off of the intake ducting and put it in an empty bottled water bottle (clear plastic). After running it in stop and go traffic, flooring it and then traveling at highway speeds for about 20-25 miles, there was hardly any oil residue in the plastic bottle. If I have to leave it on there for 1,000 miles, I don't know if I can stand it. The fumes in the engine compartment from that vent tube are pretty strong........ and enter the passenger compartment even with recirculate air in the "on" position.

I burned about 1-2 quarts after traveling 400 miles this week. I dunno but it is sure starting to sound like a turbo to me.

JMH

[Brian Carlton]

See if you can stand it for 400 miles. If you burn another 1-2 quarts, then the turbo seals are then highly suspect.

While you are at it...break that EGR if you haven't already...

I mean..."adjust it".

[rdanz]

Originally Posted by Brandon314159

While you are at it...break that EGR if you haven't already...

I mean..."adjust it".

"Adjusting or Breaking" the EGR in a 603 is not the same asin a 5 cylinder diesel.

Causes a huge loss in performance in the 603 and can even damage the engine.

[Hatterasguy]

Bah where do you get your info? In Europe no 603 ever came with an egr they are a US spec only thing. On the older 603's it is very simple put a nice plate between the egr and crossover, the sooner you do this the better egr's are horrible for these. However on the newer 3.5 603's you cannot do that it is a little more complicated. But Oldsouth figured it out do a search on his posts.

[rdanz]

Originally Posted by Hatterasguy

Bah where do you get your info? In Europe no 603 ever came with an egr they are a US spec only thing. On the older 603's it is very simple put a nice plate between the egr and crossover, the sooner you do this the better egr's are horrible for these. However on the newer 3.5 603's you cannot do that it is a little more complicated. But Oldsouth figured it out do a search on his posts.

1992 300D EGR req. Most Knowledgable Tech
Ask old south if his cars performance improved after his "expensive"egr disconnect?
This is not a simple fix like the 5 cylinder egr's
You need to change things like wastegate and other stuff.
I rather just clean out my manifold every few months.
If it ain't broke don't fix it.

[Hatterasguy]

Well taking a manifold off of a 603 isn't as simple as a 606. So cleaning it every few months can be a pita.

Also on the 3L 603's it is as simple as the 617's, just block the stupid valve. Have you ever seen the thick black tar these things feed into these engines? My valves looked like crap good riddence. MB only put these stupid things on for the US market CA probably.

[rwthomas1]

Ask old south if his cars performance improved after his "expensive"egr disconnect?

Well the first thing to do is read the correct post not one with a bunch of opinions and heresay.... Read this one: Success - I did it!

Yes, not as easy as a 617 but not all that hard either. Sorry but the "leave it stock" mentality is BS when the Euro versions of the same car don't have the damned EGR on them. Removing a manifold to clean out crap is not a solution. Even the new TDI's are having issues with this but thankfully you can buy software and turn down the EGR duty cycle to minimize it. RT

[rdanz]

As far as me removing my manifold . Its the best solution for me being my engine is still under warranty. And messing with the EGR would void that.