After repair car sounds like a diesel at low rpm
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Joined: Feb 2019
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After repair car sounds like a diesel at low rpm
Ok guys need some help. A little background into it... I have a 99z24 Cav, one day the car crapped out on me. I had multiple misfires and no power. The engine also shook back and forth really badly about 2-3 inches both ways. I believe the fuel pressure regulator caused the original problem and it snowballed from there. I replaced the regulator, a vacuum line, intake resonator seal, fuel filter, spark plugs, and coil boots . This still didn’t fix anything. I gave the car to my mechanic and it gave him a lot of trouble. One of the first things he and I noticed is the cat was glowing red. He cut it off and replaced it because it was clogged. He replaced both coil packs, coil pack housing because it was cracked, and ignition module. The car still ran terrible, he ended up having to retime the cams as one or both (not sure) had jumped timing. He messed with it some more and while messing with it, it burned up the new coil packs. Somehow at some point the cams jumped timing again. Therefore he replaced the coil packs and timing tensioner. The car is running smooth now except it sounds like a Diesel engine. It never sounded like this before. I have plenty of power and smooth idle. Noise seems to go away with more rpm. I can feel the clacking when holding a screwdriver on the engine. I feel like it’s coming from more of the timing cover area but can’t be sure. Do these engines have VCT? I don’t know much about these cars. Any ideas?
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No. A quick check on Wikipedia says the LD9 engine does not use variable valve timing, nor any Cavalier. If you haven't checked for diagnostic faults that's usually the best place to start. Sounds like you've done everything but the injectors. It's a 20 year old engine now so you might be looking at a top end rebuild at least.
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Well not that it makes much difference but the car only has 86k original miles. Like I said the car runs and drives like normal but it has a loud tick/clacking sound. I don’t think injectors are a problem. Also there aren’t any codes as the original problem seems to be fixed.
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I’m going to try and pull the valve cover this weekend. I did drive the car to work yesterday. The noise only seems to come after the car is warmed up. Think the oil pressure is low, causing a lack of pressure on the tensioner? Could I just use a little thicker oil?
