1979-1993 & 94 Conv [Subscribe to Daily Digest] |
So here's how it is: I picked up a very nice '93 C900 convert, turbo. Body and top perfect, interior very good, 148K. Advertised as "overheated, needs head gasket". Previous owner's girlfriend had 'run it until it quit'. BAD
Well, I've worked on these cars some over the last 7 years, changed one from auto to 5-speed, changed four head gaskets(tho none from overheating), removed and replaced engines/transmissions etc. Got my own workplace with a lift, so this should be pretty straitforward. Got it home and set to work.
Compression test before anything done was 60-25-15-27(with the other three sparkplugs in place)[test done with starter only, of course, as it would not start] Removed the head, cleaned things up and put a steel strait edge on it, and looks like about .025" warp; not too surprised. Took it to my local machine shop and he says, after consulting his books, it can be milled and be within spec. Good. $40. Picked it up a day later and he says, "Oh, I had to go .006 under, but I think you are OK." Uh huh. We talked about a shim, but shim not available for this engine. Great. But just to be sure on the valve clearance, I would put the play dough on the piston face and cycle the engine with the old gasket and head bolted snug.
Did that and Wonderful! no valve marks in the play dough. Hooray! Put on
the new head gasket, intake and exhaust gaskets, hooked up enough to see if it would run. NOthing. Got good fuel pressure at the rail, got spark. Nada.
Cranking sound a little different from my other Saabs, but oh well. If fact, it sounds a lot like when I did the first compression test.
Tested compression again(other three plugs in place)and WORSE! 57-20-20-50
So...time to put the air on each cyl (watching the camshafts so both valves are closed) to see where the leakage is. Air readily heard escaping thru the intake manifold(listening at the throttle body). every cyl. Plus, testing again with the other plugs out, I can feel air coming out spark plug holes. Got to be thru the intake manifold. New headgasket is torqued to spec. And I cannot hear much out the exhaust side because the turbo is bolted up.Listing at the oil fill pipe, nothing heard.
So... A pretty kettle of fish.
NOw is this just a matter of very bad valves? Damaged from extreme overheating? Is this possible/likely?
Are there other sleepers here such that I should just trash the whole engine and look for a donor car? I do have several 2.1 non-turbo 16v heads available to me, but it looks like[from posts here] that it is necessary to change intake cam, intake manifold and throttle body.
Any advice would be appreciated.
posted by 96.243.8...
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