This can't be good....
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This can't be good....
Heard a knocking/rattling noise on light throttling at around 3000 rpms in my motor...took it to my mechanic, he listened to it and said its the crankshaft and bearings. does that sound about right?
Captain
Joined: Aug 2005
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From: Rose Hill, KS
RE: This can't be good....
A knock is sort of hard to just generalize like that. Depending on the exact sound of it, it is very possible that it is the crank. Could be other things though also. How many miles does the motor have on it?
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RE: This can't be good....
Motor has about 104,000 miles on it. The mechanic is pretty good, but wont touch a crankshaft....he hates dealin with it, lol. It sounds kinda like a rattling/pecking...it does it between 2000 and 3500 RPMs, loudest at 3000. You can hear it best when you give it light throttle at high RPMs...if you hammer down on it, you can barely hear it.
Don't know if this is related, but my oil pressure has been acting funny lately. It stays right below 40 and won't move with acceleration. Yesterday I pulled up to a stoplight and the oil pressure bottomed out at 0. I shut it down and restarted it and the pressure went back to right below 40. I checked the oil, it was only 1-1/2 quarts low, so i added a quart...still didnt change the sound any or the oil pressure.
Don't know if this is related, but my oil pressure has been acting funny lately. It stays right below 40 and won't move with acceleration. Yesterday I pulled up to a stoplight and the oil pressure bottomed out at 0. I shut it down and restarted it and the pressure went back to right below 40. I checked the oil, it was only 1-1/2 quarts low, so i added a quart...still didnt change the sound any or the oil pressure.
Captain
Joined: Aug 2005
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From: Rose Hill, KS
RE: This can't be good....
ORIGINAL: miknwv
Motor has about 104,000 miles on it. The mechanic is pretty good, but wont touch a crankshaft....he hates dealin with it, lol. It sounds kinda like a rattling/pecking...it does it between 2000 and 3500 RPMs, loudest at 3000. You can hear it best when you give it light throttle at high RPMs...if you hammer down on it, you can barely hear it.
Don't know if this is related, but my oil pressure has been acting funny lately. It stays right below 40 and won't move with acceleration. Yesterday I pulled up to a stoplight and the oil pressure bottomed out at 0. I shut it down and restarted it and the pressure went back to right below 40. I checked the oil, it was only 1-1/2 quarts low, so i added a quart...still didnt change the sound any or the oil pressure.
Motor has about 104,000 miles on it. The mechanic is pretty good, but wont touch a crankshaft....he hates dealin with it, lol. It sounds kinda like a rattling/pecking...it does it between 2000 and 3500 RPMs, loudest at 3000. You can hear it best when you give it light throttle at high RPMs...if you hammer down on it, you can barely hear it.
Don't know if this is related, but my oil pressure has been acting funny lately. It stays right below 40 and won't move with acceleration. Yesterday I pulled up to a stoplight and the oil pressure bottomed out at 0. I shut it down and restarted it and the pressure went back to right below 40. I checked the oil, it was only 1-1/2 quarts low, so i added a quart...still didnt change the sound any or the oil pressure.
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RE: This can't be good....
Yeah...I just got off the phone with several people, they've told me I'm better off buying a used factory motor and just replacing it. Any thoughts on where I can get a cheap one or what to look for, etc?
Captain
Joined: Aug 2005
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From: Rose Hill, KS
RE: This can't be good....
It just depends, are looking to stay stock with the motor or upgrade a little? There is probably a good engine rebuilder in your area if you are looking to stay stock. A crate motor is another option. I personally would rebuild it myself if my truck did that. So how much do you want to spend and what are you planning to do with your truck?
Legend
Joined: May 2005
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From: Central Oklahoma
RE: This can't be good....
Rebuild it. I am in the process of rebuilding my engine and I'm upgrading many items (brass core plugs, aluminum water pump, hi-flow oil pump) and I was able to stay standard. I am reusing the rods, pistons, cam, and crank. I did some porting and polishing on the heads (not the greatest, but better than nothing) and I'm going to be doing the intake mods. I bet my total outlay is less than the $1,300 I have thus far paid the builder. I am going to install a higher output alternator and a new radiator. You can check out the thread about my engine in my sigline.
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From: Massachusetts (Central)
RE: This can't be good....
If your losing oil and it is knocking/pinging. Check yout plenum gasket, if your not familiar with this its the pan at the bottom of the intake manifold and it is known to go bad on these generations, it happened to me. Take the air intake off and look down throught the butterflies in the throttlebody and see if you see and oil in the bottom of the intake, if you do the plenum gasket is blown, if it is blown do not wait too long to fix it. This problem caused a burnt valve for me, and after you fix it i would run a cleaner thought the engine to get the oil out, like Sea Foam.
Good Luck
Good Luck
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RE: This can't be good....
I just had the plenum replaced a month and a half ago. I've heard the motor ping with the "spark knock" and it's a totally different sound. This noise is directly proportional to teh amount of RPMs I'm running.
Legend
Joined: May 2005
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From: Central Oklahoma
RE: This can't be good....
I forgot to mention that I wonder if you either have a rod knocking or you have spun a bearing. I had a similar issue present itself on a 4.3L Chevy Blazer, where rod #4 snapped and *WHUMP* shut down the engine. It was not a pretty sight.