1991 740 turbo+ problem(s). I have approx. 189K on the OD and a week ago or so I started hearing what sounded like an exhaust leak. I check the manifold, downpipe and couldn't find anything that felt like a leak. I did have the head gasket replaced 55K miles ago. This car has always run strong except for this situation. I'm at loss where to look next so I throwing this out to the group to see if we can find an answer....or should I just consider the red dragon DOA! Thanks in advance for your help.
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Gee, DOA for an exhaust leak? You are a cruel master!

First, are you sure it's an exhaust leak? What are the symptoms, just a sound? What part of the car is it coming from? Front, back (muffler)? Generally not a hard problem to solve...

 

It sounds like an exhaust leak!! ....It's coming from the right front area of the motor... at high idle it seems to disappear..driving under load feels like its missing on a cylinder... replaced the plugs and wires last weekend and problem persists... a vacuum leak would not be that loud in my experience...all suggestions welcome...

 

Keep in mind, turbo cars run both negative and positive pressure through the vac hoses. They're hard on 'em...especially with the extra heat from the turbo. That having been said, check the center and rear portion of the turbo itself. Also, where the downpipe attaches to the turbo. Exhaust leaks make the tailpipe mixture lean, the O2 gets fooled and tells the ecu to richen up the mixture so need to find it.

 

I'll check it out this weekend. thanks. report back on what I find.