geezel

My engine is nice and quiet whan cold, the first 5 minutes or so. When warm there is a lot of valve clatter. The valve lash is adjusted properly (zero lash plus 1/2 turn adjusted with engine running). What component is actually making the noise? Is there anything I can or should do?

joeveto

How many miles are on your car? I had a valve clatter I could not remove. Turns out, I had a bad lifter. And a bad cam...

geezel

I've got 70k miles on the car plus new cam and lifters. It's not just a valve or two, the whole system appears to be noisy.


[Modified by geezel, 2:31 PM 3/11/2004]

UDLUV12

Geezel,
If I were you, I think I would have to revisit the valves, and make sure your adjustments are true.
Perhaps if you can give us the sequence you used to adjust the valves to begin with?
What grade of oil are you using? Same oil as before new cam and lifters added? How long ago was cam and lifters added? Usually, if valves are out of sequence, you can feel it in the pedal. Have you felt any lose of pedal response? What year Vette?


[Modified by UDLUV12, 6:17 PM 3/11/2004]

geezel

I tried several times with engine not runnig using generally accepted adjustment procedures. I think I always got them too tight due to trouble finding zero lash. Performance improved drastically after adjusting with engine running. Always the clatter no matter which method.
I,ve ran both 5W-30 and 10W-30 oil, doesn't seem to matter which.
I'm quite sure the cam & distruibuter are installed correctly and not part of the problem.
Throttle response is great. It's an '86.

CFI-EFI

Did you change rocker arms? Or heads? Just a cam and lifters?

RACE ON!!!

geezel

Crane Gold 1.5 non self-aligning (I've got guide bars) New valve springs also per TPIS reccomendations when I purchased the cam from them. No head work.

CFI-EFI

What are "guide bars"? Push rod guide plates? Where from? Stock iron heads? Any work done to the heads? I'm trying to help, here. I have an idea or two, but I need to know what you've put this together with.

RACE ON!!!

UDLUV12

Geezel,
It sounds as if you are doing all the right things. Has me stumped.

Perhaps a call to TPiS...since you got the cam and lifters from them.

They work on these combinations often, and should be able to offer a solution.

geezel

Sorry.. Guide "plates" is correct. Aluminum heads which were stock whan I began as far as I can tell.

CFI-EFI

geezel IM'ed me and told me he is gone until Monday.

My concern was that he had more than one method of rocker arm alignment employed with this combination. It doesn't appear that way, now. Thsi IS puzzling. We'll work on it next week.

RACE ON!!!

olman

Check the drippers in the valve covers...May need grinding down

geezel

They're allready ground off.

CFI-EFI

We have pretty well hashed over the valve train and everything seems to be in order. Quiet cold. Noisy warmed up. Right? Is the cam and rocker arms the only thing you did in this operation? Your discription of the adjustment, sounds fine. What happens to the oil pressure between "quiet" and "noisy"? It seems as though you have a drastic drop in pressure, warmed up.

RACE ON!!!

PS. After it goes noisy and you shut it off. Is it quiet again, cold, until it re-warms up?


[Modified by CFI-EFI, 10:02 AM 3/15/2004]

geezel

I replaced lifters, springs and timing chain also (all TPIS stuff). It sure sounds like clatter is from above at rocker area, not lifters. Always quiet when cold. Noisy when warm or hot, even after shut-off & restart. I don't think oil pressure is an issue but I'll check in the next couple of hours.
Any chance the Crane roller rockers have gone south for some reason?

olman

Did you grind enough off? Something has to be "growing" a little bit with the heat causing the noise. I'd call TPIS and ask them too. Is it all the lifters or just one or two?

geezel

I believe most all the valves are contributing to the clatter. TPIS doesn't have any insights. They say if the oil pressur is good and the valves are adjusted properly, I'm good to go, it could just be the "nature of the set-up".

JAKE

Light weight oil, like 10W30 contributes to valve train noise.

Valve train is quiet when oil is cold; telling me the oil viscosity is high and is quieting valve train noise.

Valve train becomes noisey when engine has warmed up; telling me oil viscosity is lower resulting in more noise.

The different between the two conditions is temperature affecting oil viscosity.

Try a load of 15W50 Mobil 1 or Pennzoil GT 20W50 or Valvoline VR1 20W50; you'll notice the diifference.

Jake

geezel

Probably a great idea. Is the higher viscosity oil ok whan the Owner's Manual reccomends 5W-30?
Oil pressure is good (I think) 60-65 PSI cold idle, 40-45 PSI warm idle, 54-55 PSI warm cruising.


[Modified by geezel, 5:24 PM 3/16/2004]