I found a broken bolt or two on my rear exhaust manifold. I haven't inspected front manifold yet.........
I would appreciate some advice: How (in what ways) will an exhaust leak affect the performance of an '86 V6 2.8. What type of engines problems are associated with exhaust leaks

My question, I guess, is haow do I analyze this situation in order to determine if it is worth replacing the bolts. Is there some way to measure the amount of exhaust leak caused by the broken bolts?

Any advice appreciated

exhaust leak = possible FIRE!
exhaust leak = bad performance

A broken bolt won't cause a bad leak there are two to each port.

But ask your self WHY are they broke?

Be sure to check for cracks in the manifold

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98 3800SC GTP motor, 5sp.
custom hood,trunk,side scoops,IRM front spoiler

You might have a crack in the manifold. I was told that the engine could run either rich or lean with an exhaust leak (ie. cracked manifold). I have never heard that it was a fire hazard.

This is just what I have heard I have no proof for any of these statements so take them for what they are worth.

You might be wise to replace your exhaust manifolds and the studs holding them on. My advice is to use german studs (volkswagen). A mechanic I know personally says he works on german cars (BMW, Mercedes, VW) and hes never broken a stud hes taken out of a VW. I don't know where or what size to get them for the exhaust manifolds but they can be found and I recommend using them as they have less of a chance of breaking if you ever need to take them off again.

Replacing the bolts with studs is an excellent idea. If you cant find volkswagon try Rodney Dickmans set. The link is in the vendors page. I have them, good quality, fast service too.

Some one correct me if I am in error, from what I have read on the forum, the blown out exhaust gaskets cause burned valves.

Do a search on bolt extraction and also on manifold gaskets. Arm your self with plenty of 13mm sockets, wrenches, and ratchet wrenches.

Also be prepared for the worst. Some manifold jobs go well and other folks have difficulties.

We will be here for you, keep us posted, Ok?

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jetman
Silver 86 SE 2M6 4-speed, with "check wallet light"

If the leak is located such that air can be sucked into the exhaust stream, the oxygen in that air will cause the O2 sensor to supply a false lean reading to the ECM, which will in turn run the fuel up until the O2 is reading correctly at the sensor, regardless of how rich it will be in the cylinders.

JazzMan