My truck just recently started to knock well I wouldnt really say a knock its not detonating or anything, Im pretty sure its my lifters making noise, it only happens on cold starts and goes away after about 30 seconds of running if I turn it on,on a cold morning and dont give it gas,just let it idle for a little I dont hear them making noise and then its good to go, but if i turn it on, on a cold morning and dont let it warm up a few seconds then i hear it making noise now this is my question could it be a lifter problem were I need to replace all the lifters as a reliable source told me that this is common on those engines and all the lifters would need to be replaced OR I also looked up on ALL DATA a TSB that says the seal between the oil pump and the oil pump pickup screen gets cut on these engines which causes oil aeration and thus a lifter knocking sound only on cold starts? How can I confirm which one of these is the problem if any of these is the problem?
2007-12-17 14:49:14 · 3 answers · asked by Anonymous in Cars & Transportation ➔ Car Makes ➔ Chevrolet
heres a hint it was due for an oil change and after I changed to the oil I noticed it knocked a little less on cold starts but only for a couple days after about a week or two it started knocking like it usually does on cold starts, it dosent knock on warm starts wether the engine is cold and its warm outside or the engine is warm and its cold outside. Would a compression check tell me wether it was one of my lifters that was bad?
2007-12-17 14:53:33 · update #1
There have been some problems with aftermarket oil filters on Chevy engines in the past.The problem is the factory oil filters work better and have a anti drain back valve built into the filter.Aftermarket filters don't.Please use the factory oil filter and 5w30 motor oil the factory recommends and see if your problem goes away.Best of luck with you truck.
2007-12-17 15:18:54 · answer #1 · answered by HyperGforce 7 · 2⤊ 0⤋
This sounds like a classic case of "piston slap." Piston slap comes from a little excess clearance on the piston skirts. As the pistons warm up the clearance is reduced and the oil is able to lubricate normally with no noise. I would suggest the sythetic oils because they have better cold flow.
2007-12-19 02:49:15 · answer #2 · answered by ? 1 · 0⤊ 0⤋
sounds like you have piston knock. you would have to replace the pistons to repais nosie. i would doubt the oil pump seal is ripped or you would intermielty loose oil pressure
2007-12-18 11:49:34 · answer #3 · answered by Dan 6 · 0⤊ 0⤋