My 91 940T has an exhaust leak but I am not sure if it is from the manifold or the flange. I know it is rare to have a flange leak (where the turbo connects to the manifold) but this area has a white coating on it. The loud ticking or "tut tut" sounds like it is coming from the front of the manifold but the white on the flange looks like a good sign it may be coming from there. Studs are stripped on the manifold, so I am kind of hoping it's the flange.

Any opinions? Is the whitish color a sign of a leak or would it still be the manifold and not the flange?

Thanks

Have someone with a glove or rag plug the tailpipe while you watch the suspect areas. Pull the rag off periodically so that you don't build up too much pressure.

Charley

Connected a blower to the tailpipe and used soapy water to find the leaks. The Flange was leaking, as was #1 & #2 on the manifold gaskets. #1 stud was stripped beyond the point of normal removal. I'm not proud of it but I hi-temp welded the leaking areas (I paid $500 for the car and I would rather spend the money on a new engine/V8 swap than drop a lot of cash on the gasket removal on a 232k mile car). Most of the noise from the leak is gone now. No leaks were present either, so it worked. Looks like I may have a few other "tapping" issues.

I had to do something after rebuilding the entire front suspension and brakes etc. I hated to do it but my wife would have lost it on an expensive gasket job. This is my hobby car (4th Volvo). The interior and exterior is rough but the engine has been solid until this point. Lots of little electrical gremlins but overall a good car for the age/mileage.

If I had it to do again, I would have spent $1500 on a better 940. I am not giving up though. I am determined to keep it around for a long time. Hopefully I can drive it like this for a while until I can get a nice donor motor lined up. Next job to tackle is the low idle-500 rpm. I am sure the great minds on here can come up with something.

Thanks for all the great advice.

It's not at all rare for there to be a leak at the manifold-turbine housing interface. There's no gasket there, so it's hard to fix; it's also not usually much of a leak, especially after things warm up.
The ticking sound is probably from a head-manifold leak.

the whiteish color is good sign you are correct. if you dare on a cold engine stick your finger down there a feel for air coming out as it the engine just begins to run.

I am hoping to spend some time on it tomorrow afternoon. I'll update what I find out.

Thanks for the help and suggestions!

if the sight between the downpipe and the back of the turbo is the source of the leak have a helper wiggle the end of the tail pipe while YOU stare at the connection between the back of the turbo and downpipe. if you see play in this area after the helper wiggles all you need do it tighten the 3 nuts to eliminate the leak.