1979-1993 & 94 Conv [Subscribe to Daily Digest] |
Saabs use an oil channeling system under the valve cover. These brass channels use elbow shaped and "T" shaped plastic fittings with rubber washers that age and either break free or pull out. They are used to hold in the afore mentioned series of brass straws that feed oil to the valves and lifters. It is a STUPID design (low grade plastic INSIDE an engine!). When these plastic fittings break or pull free the valves have no oil cussion or bleeddown effect and slap the head and sound like a machine gun. As oil warms it more easily flows around this channeling system and seeps into valve lifters and cusions the machine gun sound slightly. I had this problem, and the fix was cheap and easy for what sounds exactly like your problem. Get these plastic fittings and replace the old ones after making sure the brass "straws" are free of dirt and gunk and all the tiny holes are open and free, and any old broken plastic is pulled free from the engine holes where they used to fit. Before pulling out the old stuff, inspect and even take a Polaroid picture or 2 to make sure you get the new ones in right. They are right on top of the engine, so Stevie Wonder and Ray Charles could not even miss them. ALSO, inspect the setup to see that this is indeed the problem as I am not a soothsayer. This fix takes 45 minutes with no power ratchets and 10 with. If you are already going to look at the timing chain, this adds only and extra 5 minutes at the most!
I agree that timing chain is important to evaluate, but the noise is frequently not what you have described. I just swapped a new engine into my SAAB, but not before I replaced the timing chain and tensioner outright even though the old ones looked fine. That is how important they are. It is just that I do not feel that this is YOUR problem, as I had EXACTLY your symptoms in my old SAAB and my mechanic and SAAB Guru without hesitation told me these plastic bits were the culprits and he turned out to be correct. I now have diagnosed others with the same problem and have been correct, completing the circle.
Shall I begin to sing "The Circle of Life"?
posted by 172.135.2...
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