1997 chev 5.0

[ratmn218]

88000 miles, sometimes after sitting overnight when startup it clacks im guessing a lifter, put half can of seafoam in it. my question is how many miles do i run before draining out oil?? it also is going through antifreeze,but i think that is a diferent problem.no water in oil and no big plumes of white smoke out the exaust????????????replaced intake gasket 1 time already.

[Jeremy airjer W]

half a can for 50 to 100 miles + or -. What we do in the shop with lifter noises is add half a can and let it run in the shop until the nose stops. Then change the oil, and add the other half to the new oil.

Did you notice it more when it got cold. Does it go away right away or does it take a while to stop. Would you say it is a definite tick or is it more of a hollow clack?

[ratmn218]

doesnt always do it, just sometimes after sitting overnight.to me it sounds like a lifter?when started and clicking it has good oil pressure,usually quiets down after 10 -15 seconds,then not a click to be heard.temp doesnt seem to effect it?i always change oil and filter every 3000 miles, ran seafoam in it about 1500 miles ago for a couple hundered miles then changed oil. seemed to do the trick, till lately now clacking occasionally.

[Macgyver55]

 Originally Posted By: airjer

Did you notice it more when it got cold. Does it go away right away or does it take a while to stop. Would you say it is a definite tick or is it more of a hollow clack?

I think I know where you are going with that question....

piston slap maybe? We have several units at work that have been doing it for years with no problems, but it is a bit annoying.

[ratmn218]

we have a fleet of 15 chev trucks here at work, and some do have the piston slap, so i know what that sounds like, this isnt piston slap. are these trucks known for bad lifters?this morning i started truck and timed clicking noise, 20 seconds with good oil pressure.so how long do i dare run with seafoam in oil?200 miles?full oil change 3000?

[Jeremy airjer W]

With the engine warm add 1/2 a can let it run or drive it for 10 to 15 minutes then change the oil. Add the other half to the fresh oil and drive it until your next oil change. If that doesn't take care of it than a more extensive repair may be in your future!

[wallyeye]

This sounds like a classic case of "Cold Start Knock" I had a 96 silverado that had the same simptoms. Do a search on the web for GM CSR or GM cold start knock and check it out. GM had a piston clearance issue or something like that. Once the pistons warm up enough they expand and the rattle goes away. Hope this helps.

[chickeywing]

Chevy lifters can be testy. Have you recently switched oil or filter brands? I had a Beretta that I tried running an oil 'made for today's high revving engines'. Terrible lifter clack at cold start. No noise after I went back to my old brand.

TC

[ratmn218]

wish some of you guys lived near hermantown, so you could stop and listen to this thing,seems like after changing oil, get about 1000 miles with no noise then starts making noise? maybe just seems that way?