Internal motor problem? need help bad!
Thread Starter
Melting Slicks
Joined: Jan 2008
Posts: 2,065
Likes: 1
From: Jasper Texas
Internal motor problem? need help bad!
Well, today I was driving the vette and it started to not want to rev past 2K. It would shake real bad and the motor seemed to hit a wall. With no load, the motor revs to 6500 just fine.
With the car idling, the motor has a noticeable tap like lifters and it makes a nice pop through the intake when you snap the throttle.
Broken valve spring? or bad rocker arm?
With the car idling, the motor has a noticeable tap like lifters and it makes a nice pop through the intake when you snap the throttle.
Broken valve spring? or bad rocker arm?
Le Mans Master
Joined: Aug 2000
Posts: 8,838
Likes: 31
From: Australia
Mine was similar except I had a chuffing out the exhaust
Luckily the retainer was jammed on the valve and the broken spring wound inside itself so it was still operational at full travel but was not fulling valve back on the seat when closed.
Luckily the retainer was jammed on the valve and the broken spring wound inside itself so it was still operational at full travel but was not fulling valve back on the seat when closed.
Last edited by rodj; Oct 9, 2009 at 08:59 AM.
Thread Starter
Melting Slicks
Joined: Jan 2008
Posts: 2,065
Likes: 1
From: Jasper Texas
Car wont be driven again anytime soon....just bought a brand new....mustang....
Anyway, the motor was idling very bad at cold temps, once warmed up it was pretty smooth. I pulled the valve covers today and it all looks pretty tight under there. Some of the rockers are too tight, and one is a little loose, but nothing that would cause what I have experienced. Starting to think possibly a lifter or even the cam. Next step will be to do a compression check and turn the motor over by hand and watch the valve train. I'll keep y'all posted, but I'm a busy bee!
Anyway, the motor was idling very bad at cold temps, once warmed up it was pretty smooth. I pulled the valve covers today and it all looks pretty tight under there. Some of the rockers are too tight, and one is a little loose, but nothing that would cause what I have experienced. Starting to think possibly a lifter or even the cam. Next step will be to do a compression check and turn the motor over by hand and watch the valve train. I'll keep y'all posted, but I'm a busy bee!
Thread Starter
Melting Slicks
Joined: Jan 2008
Posts: 2,065
Likes: 1
From: Jasper Texas
No I havent done any lately. Its always ran rich, and doesnt smell any worse.
I'm pretty stumped, its just wierd that with no load the motor runs great other than the slight tappets noise, but under load over 2K the motor starts to shake badly and makes a high pitched metallic noise or the noise similar to a badly squeeling belt.
I'm pretty stumped, its just wierd that with no load the motor runs great other than the slight tappets noise, but under load over 2K the motor starts to shake badly and makes a high pitched metallic noise or the noise similar to a badly squeeling belt.
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Le Mans Master
Joined: May 2004
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From: Hellinois
Finalist 2020 C4 of the Year - Modified
spun bearing. Cord, you sure have rotten luck. You may not need to pull the pan to find out, drain the oil through a paint strainer and see what you find.
Melting Slicks
Joined: Aug 2008
Posts: 2,082
Likes: 50
From: Palmdale CA
Let's not forget about the ignition....did you hear tappit noise prior to this problem?
If you check your distributor TDC, and it's off, this could indicate a timing chain problem. Late valve/ignition timing will give you a week engine performance.
If you check your distributor TDC, and it's off, this could indicate a timing chain problem. Late valve/ignition timing will give you a week engine performance.
Corvette Enthusiast
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From: So. Cal.
2025 C7 of the Year Finalist- Unmodified
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new ride
How bout some pics of the new ride?
Corvette Mike
Corvette Mike
Thread Starter
Melting Slicks
Joined: Jan 2008
Posts: 2,065
Likes: 1
From: Jasper Texas
I fired it up yesterday and heard a loud popping sound. the motor backfired and shot a vacuum cap off right at my valve cover. Smoke was coming out of the intake manifold, really whitish and whispy smoke.
Melting Slicks
Joined: Aug 2008
Posts: 2,082
Likes: 50
From: Palmdale CA
I had a leaking intake manifold on a 3.1ltr a few years back, anti-freeze was leaking both "internal" & "externally", this caused my lifters to tap loudly, a new intake gasket, and oil change cured my problem...do you have a leaking intake?
I would move forward with a prelimanary Distributor ignition timing check.
I would move forward with a prelimanary Distributor ignition timing check.
Le Mans Master
Joined: Dec 2000
Posts: 7,839
Likes: 22
From: San Diego, Ca
The 3.1's were a different animal with multiple Bulletins about leaking intake gaskets (which took a "compression set" in GM speak allowing the engine to suck a boatload of oil). This sounds like a blown head gasket. Pull plugs and rotate the engine by hand; then see if coolant flows out of any of the holes.
Head will need milled which means both need to be milled. May be parting out, will update. 