Tappet noise?

[Don W.]

OK, I know you all are not here to hear it but I've got a noise on cold start-up that sounds like a loose tappet, It slowly goes away as the engine warms until it's gone by 150* or so. Trouble is, it's slowly getting worse. Wasn't there at all, say, 6 months ago. Doesn't sound heavy enough to be a piston. Engine doesn't use any oil to speak of. Maybe a qt between changes and it takes awhile to get there. Truck does race most weeks. Quite sure it's never been over reved, at least by me and I've had it 4+ years. Never had the valve covers off. Engine runs well otherwise.

Oil was Mobile 1, now Royal Purple. Pan was off last winter and was clean.

Thoughts?

TIA

 

[jbone]

Re: Tappet noise?

this may be a completely stupid reply but here it goes.... I dont think we have tappets do we? I thought ours were rollers :dunno:

 

[SY2455]

Re: Tappet noise?

this may be a completely stupid reply but here it goes.... I dont think we have tappets do we? I thought ours were rollers :dunno:

Yes, We have tappets. They are of the Hyd Roller type. Don have you eliminated the noise from the fuel injectors?

 

[jbone]

Re: Tappet noise?

Yes, We have tappets. They are of the Hyd Roller type. Don have you eliminated the noise from the fuel injectors?

learn something new everyday. Thanks!!

 

[Don W.]

Re: Tappet noise?

Sorry, tappets are old school. Sometimes hard for us old guys to change our lingo.:rotf:

Anyhow, a more accurate description would be rocker noise. Quite sure it's not the inj's. They sound like a miniature machine gun, can only hear them at idle. This noise is best described as a loose rocker. You can hear it in the cab. Like I said it slowly quiets down as the engine warms. Thinking I'm prolly gonna have to pull the covers and check the rocker preload but why would it loosen? Do I have a cam-follower/tappet/lifter:lol: going bad?

 

[SY2455]

Re: Tappet noise?

When you pull the cover check the rocker arm stud. Might be pulling out out the head. Don't ask how I know.

 

[Don W.]

Re: Tappet noise?

When you pull the cover check the rocker arm stud. Might be pulling out out the head. Don't ask how I know.

Ya I know. Didn't want to mention that. Bad luck....

 

[SY2455]

Re: Tappet noise?

Sorry, tappets are old school. Sometimes hard for us old guys to change our lingo.:rotf:

Hey, who you calling old. The way I see it - You don't have time to be old if you own one of these trucks.:rotf: :tup:

 

[sbwrench]

Re: Tappet noise?

Hi Don,
Al here. Met you at Infineon the other week. Did the noise occur after you switched oils? A difference in the additive package in the oils, ie: more or less detergent, can break up loose built up deposits and cause a marginal lifter to start making noises. Might be as simple as readjusting the lifter preload.Royal Purple is really good stuff. We did some development with it in the early 90"s but it's awfully thin compared to comparable grades of other brands.

You're not old, just experienced

 

[Don W.]

Re: Tappet noise?

Thanks for the kind comments regarding age. That truck -is- keeping me young. And yes, Al, I do remember you. Really appreciate you stopping by. And yes, it did occur when I switched to Royal Purple. Will take a look. Very busy next few weeks (daughter getting married) but will report when I can.

Thanks all, :tup:

 

[1madgumby]

Re: Tappet noise?

what you are hear is piston slap, it is normal, most all 4.3's have it, GM did not want to spend the money coating all the pictons to get rid of that noise. mine has it, nothing to worrie about. how many miles do you have on it.?

AJ.

 

[gkrcr882]

Re: Tappet noise?

I would hope it's not piston slap. Piston slap can lead to cracked/broken skirts, not a good thing.

 

[Don W.]

Re: Tappet noise?

64,440 miles. I've been around engines a long time. This sounds like a loose rocker. Not to say it couldn't be piston slap since I know stranger sounds have come from engines, it's just not my first guess. No racing for two weeks so maybe I can find the time to pull the rockers. Gaskets need changing anyway.

I thought coating pistons was to reduce friction not "fix" piston slap? Zillions of engines were built without coated pistons and no slap.