OM603 Exhaust Gasket Leak
 

I occasionally smelled diesel exhaust when stopped and idling. I figured I should investigate.

I pressurized the system, sprayed it with soapy water, and found this:

https://i.imgur.com/QbH1vKVl.jpeg

Ok, so I’ll need a manifold gasket at least. What else do I need to know?

I assume the whole turbo and entire manifold needs to come off. What else? What parts should be replaced when it’s all apart? What hardware like studs and nuts need to be replaced?

Thanks!!

When the manifold is off and put a precision straight edge on it to check to see that it is not warped. If it something really obvious a less precision flat area would be a carpenter's level long enough metal surface to span the manifold flat surfaces.

More of a pain to do is to clean the surfaces on the head and the manifold and bolt it back on with no gasket and see if you can get the thinnest feeler gauge you have anywhere through any gaps.

Good idea, thanks!

All the accordions and whatnot are leak free. I know the turbo exhaust flange is able to be removed because I recently had it off to replace the flex section of the exhaust pipe (which is all leak free too).

What’s the deal with the studs? Steel studs into an aluminum head…. And as I understand it, there aren’t many threads in there. What’s the best way to get the guts off? A splitter? Right angle impact? Should I be concerned?

If I’m not mistaken, the whole turbo and everything needs to come off. So the. I need drain pipe gaskets, right? None of my 60x engines leak oil from the turbo. I had a 617 that did once from the drain gasket. Does the 603 engine drain tube leak in the middle like a 617? Anything else I should do while the manifold is off and turbo is out? Maybe some sort of turbo rebuild? Is it a T3 on the 3.5L 603?

Thanks!

I only have experience on w 617.952. On that the studs into the iron head onyx had like 4 threads on them. The nuts are copper.

I have no idea on yours.

I had the turbo off and on mine a couple times and reused the same oring that makes the seal in the center of the pipe. never had any leaks. Last time I put it all back together with a new gasket on the drain flange just for good luck.
Some of the best money I’ve spent was on a turbo rebuild from G pop shop. Really remarkable was the improvement in turbo performance.