Load baring knock.

I also posted this in the SVT forum but it's not as viewed so I wanted to post it here also.

So, I'm pulling into my apartment complex in my 97 Cobra. I speed up a little to get to the speed bump and when I reach 2000rpm I hear a knock. WTF? I find out after driving around to better hear it that it only knocks between 2000 and 4000rpm.

First thing I did was check the oil, it was a quart low, I topped it off. Knock still there. I changed my oil from 5w30 to 10w40 both full synthetic. No help.

I don't have any loss of power or anything except that knock. Most people are telling me that it's the crankshaft bearings. Is their an EASY way I can tell if this is the problem? I don't really know what I'm doing and I'm not ripping apart the engine.

If this is the problem about how much would this cost to fix?

*sigh* I miss my car.

BurningRubber said:

I beleive one way to check is to unclip a fuel injector (or coil pack, but unplugging the injector wont allow unused fuel to puddle in the cylinder) from its electrical harness one at a time and listen to see if the noise is still present or if it is less noticable.

If it quiets down due to there being much less of a load on that cylinder, then you are on your way to pinpointing which cylinder/cylinders may be the problem.


Someone correct me if I am wrong.

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Someone told me about doing that but I don't know enough about it. They said take a plug one at a time off of the coil pack and ground it to the block and start it to see if the sound goes away or changes. But once again, I'm not trying to die.

twogts4us said:

Running thicker oil won't help the issue, actually it hurts it.

This sounds like you are describing detonation. What octane are you running?

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How's the thicker oil hurting it?

I'm running 93, I tried putting a booster in there also thinking it was bad gas when it first started.