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post #1 of (permalink) Old 03-01-2003, 01:05 AM Thread Starter
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Very loud engine nouse

I own a '95 YJ with the 2.5L and lately there has been a very loud knocking sound coming from the bottom of the engine torwards the front of it. You can hear it all the time and is very fast, many times a second at idle. Only guess I've gotten from someone so far is the timing chain might be worn and hitting something. Could this be it? The guy did not sound too sure.
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post #2 of (permalink) Old 03-01-2003, 03:23 AM
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Re: Very loud engine nouse

1. Listen to see if it's
a. Coming from the front of the engien,
b. Bottom of the engine.
2. Sounds like a rod or main bearing.
3. A timing chain making noise like that would likely kill the engine timing.
4. With the engine running,
5. Pull one spark plug wire off, one cylinder at time.
6. If the noise goes away,
7. You've isolated the problem to that cylinder as
8. The load's been removed.
9. If the noise is still there... put the plug wire back on, and
9. Go on to the next cylinder.
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post #3 of (permalink) Old 03-01-2003, 07:22 AM
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Re: Very loud engine nouse

My 95 2.5L rio grande was doing almost the same thing. When it was cold I would get a nocking noise from the passenger side of the engine and would also sond like it is coming form under the engine. it would sound like someone knocking there knuckles up and down the engine and would go away when warmed up with just a slight noise then. I replaced the lifters in the #4 cylinder and the noise all went away with the exception of the other lifters which I plan an replacing. My engine has 104,000 and everything else is fine. I flushed the engine, dropped the oil pan and cleaned it all out. When I replace the other lifters I think I am going to replace the rocker arms and push rods to try and eliminate the rest of the valve train noise the best I can.

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post #4 of (permalink) Old 03-09-2003, 12:58 PM Thread Starter
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Re: Very loud engine nouse

Alright well the sound is coming from the bottom of the engine and also sounds like it is more to the rear than to the front of the engine. I pulled each spark plug wire at a time and the noise was still there for each time. (also got a good shock when trying to put one of the wires back on while it was running) Seems like the sound might be coming from the bottom of the oil pan or that other pan closer to the front of the jeep. Also, the noise is always constant. It doesn't go away when the engine warms up or anything like that. Any more ideas on what it might be or how to check it? thanks for the help so far
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post #5 of (permalink) Old 03-09-2003, 10:56 PM
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Re: Very loud engine nouse

one time i ran into a knocking noise that had everyone stumped we tryed a lot of diferent things and found out almost by accedent that we had put a small dent in the gaurd for the flywheel and it made a noise that sounded just like a collapsed lifter. another odd thing to check for is if you could have dented your oilpan just enough to cause it to come into contact with the crankshaft to make a tapping sound
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