1989 saab 900 turbo
6 Answers
Does it make the noise when going round corners? Turn in a tight circle left then right, if you hear knocking then the likely culprit is the CV on the outside of the turn.
Can you describe it the sound more? Is it on the top of the engine? It may just be the timing chain.
it happens as soon as i turn the car on and rev it it sounds like its from the front top of the engine
It's probably either the timing chain rubbing against the dried out rubber buffer pad on the inside of the valve cover (you can unbolt the valve cover and look... it's easy and you won't mess anything up..), or your valves themselves are making the noise. My SPG has a slight valve noise. It's not that big a deal. I also doubt it's your CV joints. 2 websites that have good tech. forums are www.saablink.net and www.saabcentral.com I'm on both. (DanF.)
Is it 16 valve engine? Then it might be one of the hydraulic valve lifters, they often make that kind of sound. You can get a new set of lifters for about 100$ from ebay. If the engine is 8 valve, then the valves just need some adjustment(with some shimms).