Hello Buick fans, as the title says, the 455 in my G.S. has loud lifter noise, noticeable more so when driving around town with the windows rolled up. Last year I did a re-fresh on engine, and added t/a heads from Mike Weiss, new rocker assemblies, and 288-94h cam from t/a perf. Engine has speed pro forged pistons at 0 deck, performer intake, q-jet, and headers. Engine seems to run well, idle is good, and engine seems to make good power, however noise drives me nuts. I have had the valve covers off three times with engine idling and every thing seems to be working fine, no up and down movement on pushrods on valves that were closed. Lifter pre-load is set correctly. Engine has less than 1500 miles since re-fresh. Any one else have a issue like this? Could I have contaminated lifters on start up if block was not perfectly clean? I am ready to pull intake and replace lifters. Also brake in oil when drained was rather dark, and drain plug magnet had some iron residue. Thanks for any and all responses. Al
No it is not pinging, I am familiar with the sound. Timing is set at 20* at idle, 34* total mechanical with about 10* from vacuum can on ported vacuum source.
Exhaust noise? Leak at the headers? Windows up=louder noise points that way.... Can many times sound like a lifter. Loose plug can also cause this
The title of your thread is lifter noise under load. That made me think of ping. If you are sure it isn't pinging, then it may be valve noise, but there is no reason it would appear under load only. Aluminum heads grow more when hot, so they frequently need more lifter preload then iron. Is the noise at idle as well? Could also be the lifter itself. I have a roller cam, and I recently switched from the Morel lifters to the Johnson roller lifters. It made a big difference. What kind of lifters are you using?
Thanks for the reply Larry, what I mean by under load is cruising at a steady speed, say 2500 r.p.m. When I accelerate modestly not so noticeable. Idle is more a rocker arm sound not the same noise. Lifters came with cam from t/a.
Sounds like classic front cam bearing issue to me, .... though the lifter noise would be more prominent on the left side. Larry
Engine has t/a dual groove cam bearings, plus a small channel cut in top of first cam journal connecting both oil galleys ( done many years ago )
Is it more noticeable after the engine is warmed up? Mine is totally quiet until about 180 degrees then the lash adjustment seems a little loose. Like Larry says the aluminum heads grow a little when hot. Bob H.
Pull some plugs and Post up a few pictures of them before your able to see the inside of your block from the outside! Aluminum heads will grow in height some .006" to .008" from what I have seen when up to temp.
exhaust manifold leak is the first thing that popped into my brain. I have been known to be wrong from time to time though..... keep us posted.
So I drove car today with vacuum advance disconnected, noise still there. After driving it some more maybe it is only one or two lifters hammering away. Possibly stuck lifter or cam lobe issue? Will take some more investigating with valve covers off and engine idling and hose to my ear to try and isolate noise. However garage door opener just quit, so that's a priority right now.
The way you use the word "hammering" is consistent with detonation. Here's a backyard procedure I'd throw together to test this. I know your advance at idle is 20*. Set it at 10* for starters and retest for the noise. If the noise is still there then retard it to the point that the engine is barely idling. Now go out and test it to see if it is making the same noise. If it is, then your problem is not detonation.
Something we missed. If a lifter is jammed / stuck or the preload is too less, then you always have the tick noise. Whats your oil pressure? If you don't have enough pressure, the hydraulic tappets won't inflate properly. At more throttle the crank is pushed out stronger from the bearing which will increase the clearance and result in an additional oil pressure drop.
Hi Rob, oil pressure at idle in park after driving on freeway is 22 psi. On freeway at 3000 rpm it is 55 psi.