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Help - Lifter Noise or exhaust leak?
Posted:
26 Sep 2005 0:13
by Rizrtse
OK...bummed out today. Need some opinions. I have a classic lifter noise on the passenger side of the valve cover. The car ran fine last week and heard nothing. Started the car up a bit cold today and heard a pronounced tick, tick noise from under the hood near the valve cover. I had a similar noise on the other side a year ago and found it to be an exhaust blow-by on the gasket. I have a rebuilt, stock, 383/4 bbl RTSE as some of you know. Completely rebuilt 1500 miles ago and in #1 condition until this setback today. The noise mellowed slightly when it warmed up but it is still there. Oil pressure on the stock gauge looked like it always has...good. I have the stock manifolds on the car. When the other side started ticking I had the manifold milled to assure a good fit with the new felpro gasket. What are the odds it happened on the other side? If I go to headers now what are the absolute best fit for this 383 with power everything? If it isnt the manifold it must be a lifter right? These are hydraulic correct? Not adjus
table - what cause this noise. Thanks friends. Steve
Posted:
26 Sep 2005 7:30
by dave-r
Chances are (even without the previous history of this problem) that it is the exhaust gasket.
You can sometimes get a sticky lifter that will go clack clack clack. Usually taking the lifter apart and cleaning it cures this.
I would start with looking at the exhaust gasket though.
Posted:
26 Sep 2005 10:43
by Rizrtse
Any header advice?
Posted:
26 Sep 2005 10:59
by dave-r
Rizrtse wrote:Any header advice?
Check it with a straight edge. Cast iron manifolds should be straight. Check for cracks though.
Steel headers leak like mad very easily and need very good soft metal gaskets. They never seal as well as the original iron type.
Posted:
26 Sep 2005 13:26
by zogg
Definatly what Dave says, make sure you get gaskets specifically made for headers and not exhaust manifolds, there is a difference to how long and well they seal. I got Felpro header performance ones on at mo.
There also seems to be some evidence that you can use a smear of RTV silicone sealent, but I would only use that if the gasket dosent seal the joint very well.
Surprising how a header leak can sound like a noisey lifter - caught me out a couple of times
Posted:
26 Sep 2005 15:42
by Follicly Challenged
Just some thoughts;
For diagnostics, can you change the "tick" sound by pulling various plug wires on that bank ? have the video camera on so we can watch the "dance" LOL, seriously though, it may be a way to verify an exhaust leak, or rocker tick which probably won't change.
If it is an exhaust leak, and you're re-using a stock "straight" manifold, try coating the gasket with "never-seize high temp." on both sides during installation, to extend gasket life.
This will allow the manifold to move around during it's thermal expansion cycle from hot to cold. The learning curve here is to remember that stock exhaust manifolds run at much higher temps than the head which is cooled by the engine cooling system, therefore expansion and contraction is far greater which "grinds" back and forth on the gasket causing eventual failure. This is why many people experience success by applying silicone, it acts to allow movement and maintain the seal.
Factory manifolds were installed with either a thin tin gasket, or, (ready for this), on some models, manifold direct to head, but either way, application of "never seize" for above reason. Believe it or not, they sealed. What warps or "tweaks" the manifolds is lack of their ability to move around @ temp. Ah, 60's engineering, gotta love it, find out what something don't like, then it was easy to go the other way to make it happy ! Detroit "wonder metal " LOL
Good luck with it, hope I haven't confused any issues with the trivia.
Posted:
26 Sep 2005 16:03
by zogg
the original 340 gaskets (maybe others) thin were pressed steel with the plug heat shields moulded all in one piece - cool. I think they are being remanufactured now.
The manifold direct to head isnt as strange as it sounds, Rover V8s didnt have them from new and dont seem to suffer any problems because of it.
Posted:
26 Sep 2005 21:14
by dave-r
Yeah but the Rover (Buick?) 3500cc engine was all alloy. I would guess it expanded more in tune with the exhaust manifolds. Plus the manifold being harder would bed into the head better?
Posted:
27 Sep 2005 0:38
by Rizrtse
Somebody suggested the copper gaskets insted of the felpro. ????
Posted:
27 Sep 2005 7:28
by dave-r
The copper or aluminium soft metal gaskets are really good. A must for steel headers but check they will fit on standard cast manifolds.
Posted:
27 Sep 2005 15:54
by zogg
The Felpro ones are somesort of metallic and carbon make up, not sure what though
Posted:
04 Oct 2005 1:26
by Rizrtse
And the result....exhaust leak! Manifold bolts loosened up just a tad and boom - 2 rip burn-throughs on the gasket. Replaced with felpro.
Posted:
04 Oct 2005 7:36
by dave-r
Don't like to say I told you so but.......