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Showing content with the highest reputation on 12/30/2021 in Posts

  1. Schurkey

    A high mileage LQ1 thread

    Inspect the head gaskets closely. There's a weak-spot on the cylinder heads near #1 and #6, the heads distort, and the head gasket pops. When it does, it tends to scuff the iron block. I had a shop cut .015 from the heads to clean them up. http://hbassociates.us/Lumina_Head_Gasket_02.jpg http://hbassociates.us/Lumina_Head_Gasket_03.jpg Verify the timing chain and the plastic guides. Everyone talks about the timing belt, but if the engine is apart anyway, you'd better have a look at the chain and it's tensioner. The exhaust valves get beaten-up pretty badly. The seats are hardened inserts; and they seem to hold up very well--but the exhaust valves look terrible. Intake valves and seats seem to hold up pretty well, as do the guides--but have the machine shop check everything. I ground my exhaust valves about .003--.005 and they cleaned-up nicely. Intakes cleaned-up at .001. Fresh-ground, and untouched used exhaust valves: http://hbassociates.us/Lumina_Valves_01.jpg A '95 engine may--or may not--have the updated camshaft/lifter oiling update. There was a service bulletin about that, with a parts "kit" that was long-ago discontinued. The only thing in the parts kit that was "special" was the new, slightly-thinner thrust plates for the camshafts. The other parts were gaskets, set screws, cup plugs--stuff you could source outside of GM. You could have your existing thrust plates shaved by your favorite machine shop. They need to make them a few thousandths thinner. If your soft plugs at the end of the camshaft are solid, you should perform the update. If the soft plugs have a small hole in the center, the update has already been done. http://hbassociates.us/Lumina_Cam_Bulletin_001.JPG http://hbassociates.us/Lumina_Cam_Bulletin_011.JPG
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