Help diagnose motor noise

[CDN OpelNut]

I drove the 2.4 stroker GT to a show about an hour away today. No issues with drivability, but the motor has developed a tick or knock that I don't like to hear.

It seems to be at the rear of the motor. I've attached a video of the noise. The car has hydraulic lifters which I thought shouldn't tap.

Any ideas are welcome. I have to pull the valve cover off tomorrow to check it over and re-torque the head. Anything in particular I should look for other than obvious issues.

Knock knock, who's there

[yellaopelgt]

collapsed lifter perhaps? Little more info might help as well, does it do it when you start it cold or is it a heat progressive noise?Smoke at start up etc...ect...
Joe

[wrench459]

Sounds like you're on the right track.
Valve train noise
raised rocker stud
broken valve spring
lash cap missing
Flattened cam lobe just for starters.

[CDN OpelNut]

Well it's a bit weird.....

I pulled the valve cover off and the #4 exhaust rocker arm was flopping around loose. I figured I didn't set it right.

When I pulled the lifter out to check it, it won't compress at all - even with a 9" c-clamp. I pulled another lifter from #2 and same story. The piston is not completely seized as it will spin, but won't depress. So basically my hydraulic lifters are solid.

These lifters soaked in oil for a week and were all pumped prior to going in the car.

[OriginalOpelGTOwner]

Seems to me the lifter is collapsed therefore you cannot compress the piston anymore. Take one apart.

[biglefti]

I tried to open the FSM on the left side of the home page to read the lifter setting procedure for the opel, but wasn't able to. Back in the 60's I used to set the lifters on my Chevy 283 engine by letting them rattle, tightening the adjuster until they became quiet, then going one full turn more a 1/4 turn at a time letting the engine smooth out before taking the next 1/4 turn. If your lifters are fully extended (pumped up), I don't think you can do any damage if you tighten them until the ticking goes away. However, if they are fully compressed and you adjusted them until the ticking goes away and then they happen to pump up, something bad might happen. Bent valve, or damaged piston. I'm sure you are aware of all this, but something to think about before jumping in.

[CDN OpelNut]

I got the lifters back into the C-clamp and and cranked until all the oil came out of the lifter. After that, I could compress the piston by hand. I guess once the lifter is full of oil it is just really hard to compress. It seemed too hard to me initially as I knew I could move them when I put then in originally.

I'll reinstall them to spec and see if it reoccurs. Thanks for the ideas so far.

Can anyone confirm that a primed lifter can't be compressed with finger pressure?

[jeff denton]

I've never had a hydraulic lifter collapse, maybe since every performance engine I've ever had was equipped with solid lifters. But I'd have to guess that if a lifter was collapsed, you could visibly see the plunger sitting lower than the retainer.
I like solid lifters. What can go wrong, as long as you know how to adjust them? What you set is what you get.
I know there are such things as really good, high quality, dependable hydraulic lifters. But is there such a thing as such that fit the Opel? I don't know, I never thought about using them.
Is there any chance the lifters are okay, but your adjusting nut was loose and backed off? Now this I have plenty of experience with. My GT won't go ten laps without this happening if I don't have them double nutted.

[CDN OpelNut]

Originally Posted by jeff denton Is there any chance the lifters are okay, but your adjusting nut was loose and backed off? Now this I have plenty of experience with. My GT won't go ten laps without this happening if I don't have them double nutted.

This is what I'm thinking. I'm going to stick them back in....

[jeff denton]

Yeah. Give it a try. If your setup has room for double nutting, try it. It worked beautifully for me, the alternative is poly-locks. I think my method is detailed here somewhere, but if you can't find it, I could always repeat it!

[Tru-Craft]

I agree with Jeff, double nutting works great.
I have also fixed loose nuts by re-crushing the self locking crimp. Even tried center punching the top threads of the nuts.
New ones is another option.
I have polylocks on my roller rockers now, that is also an option.
Check the cam lobe, lifter and rocker for wear/damage.
Probably just a loosened up rocker nut.
The lifter should not "easily"compress when pumped up.
Lyle

[grslightng02]

In the last 4 days I cleaned out my Solex and got my car driveable for the first time. Yesterday I took the car to get the oil and filter changed and just after that my car started making the EXACT same noise from the back of the motor near the firewall.

I dropped in on my mechanic and with him just listening to it he said it sounded like a lifter as well. I asked him if this is something serious, where I should not be driving the car at all, he said the car is still driveable, but to get it fixed soon would be good.

Glad to find out I'm not the only one out there with this problem.

[yellaopelgt]

Originally Posted by CDN OpelNut I got the lifters back into the C-clamp and and cranked until all the oil came out of the lifter. After that, I could compress the piston by hand. I guess once the lifter is full of oil it is just really hard to compress. It seemed too hard to me initially as I knew I could move them when I put then in originally. I'll reinstall them to spec and see if it reoccurs. Thanks for the ideas so far. Can anyone confirm that a primed lifter can't be compressed with finger pressure?

When I put my lifters in, I soaked them for a few days in oil and then pumped them up under the oil until I didnt have any more air bubbles. At this point, they became VERY difficult to pump with finger pressure. So, I think when full or primed, they have very little"give".
HTH
Joe

[CDN OpelNut]

re-installing seems to have done the trick. Now, if I could only learn not to touch those Compufire leads

BTW - anyone with Compufire have a good way to find TDC on #2 and #3. With the dizzy all rotated and advanced, I have to rely on eyeballing the lifter low point.

[jordan]

I take it you are using a new camshaft? Did you have the lifters refinished?
I prefer the the dial indicator method to determine tdc, you can buy dial indicators relatively cheap as there is no need for extreme precision.

[CDN OpelNut]

Originally Posted by jordan I take it you are using a new camshaft? Did you have the lifters refinished? I prefer the the dial indicator method to determine tdc, you can buy dial indicators relatively cheap as there is no need for extreme precision.

The cam is new, as are all the valve train components. The lifter looks fine.

I have a dial indicator so I'll try that method. Thanks

[2 Fast 4 U]

Originally Posted by CDN OpelNut BTW - anyone with Compufire have a good way to find TDC on #2 and #3. With the dizzy all rotated and advanced, I have to rely on eyeballing the lifter low point.

If the Compufire uses the rotor just turn the rotor in the position of the #2 and #3 you'll know for sure that they are at TDC [take the diz cap off ]

[jeff denton]

Can't you use the ball on the flywheel and the pointer in the bellhousing area of the block?
Did you build an engine with no perfect TDC mark for future reference? Bet you'll never do that again, huh?

[CDN OpelNut]

Originally Posted by jeff denton Can't you use the ball on the flywheel and the pointer in the bellhousing area of the block? Did you build an engine with no perfect TDC mark for future reference? Bet you'll never do that again, huh?

I can use that for #1, but the problem I've got with the Compufire is that you have to rotate the dizzy one firing position to account for firing order difference of the VW, and then I had to move it alot more just to get the initial advance to where the car would run. The dizzyshaft notch doesn't have any meaning any more, so #2 & #3 are a bit tough.

[jeff denton]

I don't understand what you're trying to do, but if you need to find TDC of #2 and 3, try my flywheel tooth counting procedure.