Engine knocking when started

[mistersean86]

I have a 93 s10 with the 4.3L. there is about 127000 on her and she runs like a champ. However when I start it up the engine makes the loudest frikkin knocking noise. it gets even louder when I put it in reverse and press the brakes. She doesnt seem like its loosing alot of power when its making this noise. And when it warms up it does not make this noise at all, only when it is cold. since it doesnt seem to affect the performance at all I dont know if I should worry about it. But its loud so If anyone knows what I should look for please let me know. I hope Igave enough info. Thanks.

[DelCoch]

Try using a NAPA oil filter. They have a valve to keep the oil from draining out of the filter when the engine is off and sitting overnight. Sounds like this is your problem.

[JaVeRo]

I had a 91 that had 90k miles on it that would knock for a few seconds on cold mornings. It did that from the first winter I had it and I bought it new. One day it started knocking when warm and didn't quit. With my brothers help we pulled the motor and tore it down. The only thing we found was where one valve had been hitting the top of the piston.

Our conclusion was that one of the valve guides was too tight. A good motor man could probably tell the difference between a rod knocking and a valve hitting the piston but we couldn't. I had the motor rebuilt since it was already out but I probably could have pulled the heads and had a valve job done and fixed it. I guess I will never know for sure.

James

[molehole]

You might want to check your belt tensioner. It can make some nasty noises when it starts going bad.

[mistersean86]

well its about due for an oil change so ill try out a NAPA filter and while im under there ill check the belt tensioner. ill post back with the results.

[BlazerLT]

Originally Posted by mistersean86

well its about due for an oil change so ill try out a NAPA filter and while im under there ill check the belt tensioner. ill post back with the results.

Lemme guess, Fram oil filter right?

Also, let the engine warm up for 2 minutes before you drive it when it has been sitting for a long time.

Also, what oil are you using?

[someguy000001]

Originally Posted by molehole

You might want to check your belt tensioner. It can make some nasty noises when it starts going bad.

You beat me to it.

I've had some cold weather light tapping for the last couple of years (for ~15 seconds or so at startup) that I was certain was lifter noise but I recently replaced the belt tensioner pulley and I haven't had it since.

[BlazerLT]

Nah guys, let's not lose focus here, he has lifter noise and high oil pressure.

[mistersean86]

according to the oil pressure guage the pressure is fine. im changing the oil on tues. and i know mechanic thats been in the game forever im gonna have him take a look at it.

[BlazerLT]

The oil pressure gauge on the dash you mean?

You have to be more clear about what you are saying.

[NHRA]

check your cooling fan, mine started makeing a hell of a noise
after i replace the transmission mount
turned out to be the fan hitting the shourd...only when it was cold
went away after it warmed up

[mistersean86]

yeah im sorry. the oil gauge on the dash. i know you cant depend on them to much. well anyways the truck is at the shop right now ill be picking it up in a few hours i left it there over night so they could witness the knocking first hand. so i should have an answer in a little bit.

[mbliss_00]

Originally Posted by mistersean86

yeah im sorry. the oil gauge on the dash. i know you cant depend on them to much. well anyways the truck is at the shop right now ill be picking it up in a few hours i left it there over night so they could witness the knocking first hand. so i should have an answer in a little bit.

Any new updates to this problem? My 98 just started this the other day...

[BlazerLT]

Originally Posted by mbliss_00

Any new updates to this problem? My 98 just started this the other day...

What oil filter are you using?