I just finished installing my power steering and at an idle I hear a knocking sound? What Are some of the things I can try before I think of the worst? It sounds like a rattle not a ping. A random sound knock. It has High compression. Initial timing is set at 14, not sure advance. I haven't put octane boost in the last 2 tanks. Rockers seem ok? Oil pressure is 50psi cold and 20 warm idle 40 crusing. Any help would be great.
Knocking???Sound need help!
mnm99
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I just finished installing my power steering and at an idle I hear a knocking sound? What Are some of the things I can try before I think of the worst? It sounds like a rattle not a ping. A random sound knock. It has High compression. Initial timing is set at 14, not sure advance. I haven't put octane boost in the last 2 tanks. Rockers seem ok? Oil pressure is 50psi cold and 20 warm idle 40 crusing. Any help would be great.
The compression is prob 10 or 11to1. I've been using 92 octane. I was going to try 1/2 gallon of Xylene when I got home. I bought the car and the guy before me added 1 bottle of octane boost per 15 gal. I filled the tank 2 times since and never put it in. I'm hoping thats what it is. Could this be a detonation? at idle? I always thought that would come on with a load.
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238 Posts
If you have a mechanical fuel pump, it can make noise. I wouldn't expect detonation at idle with 14º initial. That's fairly conservative timing. Do you know what cam is in it. 10:1 to 11:1 is a pretty large range, can you narrow it down?
I have an electric BG fuel system so mechanical is out. The cam is a comp cam 248/251 duration and 481/510 lift, thats all I know about that. Sportsman II heads 72cc decked, ported ect..., I was told from the last owner the heads were like 11.5-1, but the pistons were TRW flat top 9.75-1???? Thanks
Make sure all the pulleys are bolted down tight. I had one that was a tiny bit loose once, and when there was belt tension on it, it would pull away from the mounting face and slap back, over and over. This made a disturbing knocking noise that was tricky to find!
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chris
chris
Well I pulled wires off one at a time and I still hear it. I didn't hear it when it was cold! My oil pressure drops to about 15 at idle 900rpm and goes to around 40 driving (fast). Could it be a main bearing? I hear it as it revs too?
MMM; I think it's time to stop driving the car 'til you get this sorted out. Does it have an aftermarket oil pan and matching pickup, such as Moroso? If so, it could be a loose pickup, if locktite wasn't used to attach the tube bracket. A simple test to diagnose a loose pickup is to remove your oil filler cap on your valve cover, or the valve cover if necessary, and look for bubbles in the return oil coming off the rockers(with engine running, of course). If you see bubbles, you're sucking air, and the pickup is loose.
It sounds like your oil pressure is a bit low. I would expect at least 25 psi at 900 rpm idle, and 50+ at high speed driving! If you have no knock when cold, you probably have a bad rod bearing, or several( if not a loose pickup)! About the only solution is to tear down the engine and inspect it for problems, or have a competent machine shop do it for you.
Steve
It sounds like your oil pressure is a bit low. I would expect at least 25 psi at 900 rpm idle, and 50+ at high speed driving! If you have no knock when cold, you probably have a bad rod bearing, or several( if not a loose pickup)! About the only solution is to tear down the engine and inspect it for problems, or have a competent machine shop do it for you.
Steve
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