When I had my exhaust system replaced = last year, my mechanic removed the original studs in the heads, put in helicoils and = new studs to hold the pipes to the heads. When I had problems with the = nuts falling off the left rear studs, the studs were replaced with 8 mm = bolts. Yesterday, I heard the familiar click-click from the engine. When = I went to tighten up the bolts, the bolts would not tighten. It felt like = the helicoils were turning.

What should I advise my mechanic to = do? I have an '84 with 1.9L engine. Could be original heads, but I am = not interested in doing a head job at this time.