Exhaust leak-rough idle?
 

I've been experiencing some blown engine symptoms after running my car hard through 3rd gear last night. During the run I heard a grinding noise (not the tranny) and when I came to a stop I found that my car was idling funny. I'm on my original motor (1993 with approx. 93,000 miles). I had a pretty bad exhaust leak before the incident and now it seems to have gotten worse (or so it sounds).

I did a search last night on "blown engine symptoms" and did some reading but it looks like the car has symptoms for several different problems. I wouldn't say that the idle is drastically more rough than it's been before (it only fluctuates between the 700 RPM and 800 RPM markings when I press the brake, open/close windows, put it into gear...). It seems a little harder to get the car rolling from a stop but is fine once rolling.

I read on one previous post of a member hearing a grinding noise (twice) before noticing a rough idle. It also said somewhere on the thread about damaging the exhaust turbine. I do recall hearing a grinding noise twice also (about 2-4 seconds apart) - so maybe my turbos are gone instead of the engine.

The MAP sensor line is fine but I will admit that it has been a long while since I've changed my plugs. But will fouled plugs make that big of a difference in idling in that short of a timespan (two runs through 3rd gear in about five minutes)?

I am almost certain that it is not the LIM manifold gasket because I replaced the paper one with the metal one a couple of years ago.

I guess what I'm trying to get at is - will a bad exhaust leak (after the turbo) give off the symptoms of a blown engine? Does the car/engine get any louder after blowing?

I guess I'll have to do a compression check this weekend and change the plugs while I'm at it. Maybe it's time for a streetport - single turbo makeover? Even though part of me wants the engine to be blown, I'd rather not spend the money at this point in time.
Sorry for the long post, and thanks to anyone that took the time to read it.
Any help is appreciated.

---Jason