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> This can't be good., rocker movement - help diagnosing before tearing
iankarr
post Mar 26 2017, 09:25 AM
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Hi Guys,

So...my (new to me) 74 2.0 FI was idling great and running pretty well, except after warm it would occasionally experience a loss of power at about 3000K. Last weekend I took the dizzy out to clean and lube the plates. Also installed a pertronix and flame thrower coil. Started it up and ran like crap and uber rich. Then realized I forgot to connect the MPS hose. duh. Did that and it started up ok. It was late, so I left the car till this weekend to get the timing dialed in.

OK, so I start it today and hear this tapping racket and the engine feels like it's only running on 3 cylinders. Pulled plug wires one at a time, and it seems all are contributing.

Pulled the valve covers to see if that's where the racket was coming from and figured it was a good idea to make sure everything was properly adjusted anyway. Nothing LOOKS weird, but if I pull backwards on the #2 intake rocker, it will move about 1/4" towards me. Let it go and it returns back to contacting the valve stem. I know it isn't normal, but before I tear into things, I thought I'd check with the brain trust.Bent rod? Beginnings of dropped valve?

From what I can tell, the POs didn't drive this car much, so I wouldn't be surprised that all this new activity is exposing weaknesses....

Thanks!
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Tbrown4x4
post Mar 26 2017, 09:29 AM
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Which direction are you pulling it? Are you sliding it sideways on the pivot shaft, or are you rocking it away from the valve?

If the seat is receding, the clearance goes away. If the valve is bent the clearance increases (a lot).

If the seat falls out, it would probably hit the piston and could bend a rod. All guesses. Pictures would help of course.
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iankarr
post Mar 26 2017, 09:33 AM
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Away from the valve, towards me. None of the other rockers move more than 1/16 in that direction, so I suspect something is def different in #2 intake.... but dropped seats are usually exhaust, no? Could it be a stuck lifter? P

Here's a video...

http://www.youtube.com/watch?v=9YSRvb7qbWw


And a pic

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Krieger
post Mar 26 2017, 09:47 AM
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A long time ago I had a car with 2.0 heads that over time each of the the rocker shaft hold down studs pulled out one by one.
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r_towle
post Mar 26 2017, 10:53 AM
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Have you considered you may have hydraulic lifters?
Let it warm up, a lot.
When sitting for a long period all the oil will drain out of the lifter and it takes 5-10 minutes to fill them up so the noise level goes down.
If you have concerns, pull that rocker set, pull the rod and tube, get a magnet and pull the lifter to take a look. That can be done with the motor in place....some of them you cannot totally remove the tube but you done need to
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r_towle
post Mar 26 2017, 10:57 AM
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Btw, that head is way to clean....
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Tbrown4x4
post Mar 26 2017, 10:57 AM
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I was thinking hydraulic lifters too. There is a weak spring inside the lifter, and that might be what you're pushing against. What is the case code on the engine? Someone may have put a bus engine in it.
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stugray
post Mar 26 2017, 11:01 AM
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QUOTE(r_towle @ Mar 26 2017, 10:53 AM) *

....some of them you cannot totally remove the tube but you done need to


I used to believe that until DaveDarling straightened me out.

If you pop the tube loose and remove the outer seal, you can pull the tube out of the head towards the engine. They do not have to come out towards the outside of the car where some will hit the suspension ear before coming clear.
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Mikey914
post Mar 26 2017, 11:09 AM
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Well if you have 1/4" i would suspect that you at least need to adjust the valve clearance. Ans another member mentioned there coukd be an issue with the rocker mount. Id remove the rocker assembly and inspect the mout. If its ok assemble do a complete valve adjust and start it up.

Had a kind of simular situation with my sons car. Started making noise and lost power. Was running on 3 cylinders.

Turned out whoever installed the tube retainer spring didn't do it correctly and it rubbed on one push rod. It started wearing through until it actually cut in half. Leaving about 1/4" play. It wasn't evident right away. The mechanic he went to said dropped seat, so i helped him retrieve the car. When we got it home and disassembled that's what we found. Replaced the rod, did a valve adjust and drove it runnibg perfectly until he wrecked the car abound 20k later.
Hope this is what happened here as it was an easy fix
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r_towle
post Mar 26 2017, 11:22 AM
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QUOTE(Mikey914 @ Mar 26 2017, 01:09 PM) *

Well if you have 1/4" i would suspect that you at least need to adjust the valve clearance. Ans another member mentioned there coukd be an issue with the rocker mount. Id remove the rocker assembly and inspect the mout. If its ok assemble do a complete valve adjust and start it up.

Had a kind of simular situation with my sons car. Started making noise and lost power. Was running on 3 cylinders.

Turned out whoever installed the tube retainer spring didn't do it correctly and it rubbed on one push rod. It started wearing through until it actually cut in half. Leaving about 1/4" play. It wasn't evident right away. The mechanic he went to said dropped seat, so i helped him retrieve the car. When we got it home and disassembled that's what we found. Replaced the rod, did a valve adjust and drove it runnibg perfectly until he wrecked the car abound 20k later.
Hope this is what happened here as it was an easy fix

Kids....
Rocket killed his first after restoration....
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iankarr
post Mar 26 2017, 11:28 AM
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Thanks guys.

Unfortunately this car came with no records. But I do know the engine matches the COA. whats weird about this is that the rocker has the same amount of free play when pulled back regardless of where the engine is rotated. Will pull the rocker assembly and rod and report back!
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injunmort
post Mar 26 2017, 11:42 AM
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mine made a similar intermittent racket. the engine to bar bar mounts were loose as was the fan on the hub. tightend up and no more noise. i was convinced it was a rod bearing. took the engine out and discovered the true culprit.
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Mark Henry
post Mar 26 2017, 12:16 PM
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Springing back like that is odd and I'm wondering hydraulic as well.
Pull that rocker (any rocker) and get a push rod out, if hydraulic bus the first clue will be the PR will be steel and shorter than a stock aluminum PR, but fatter than aftermarket PR's.
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rgalla9146
post Mar 26 2017, 12:16 PM
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There is no spring in a 2.0 lifter.
As has been suggested, maybe someone put hydraulics in ?
Do the engine VIN numbers have the same font and appearance as other GA engines ?
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zipedadoo
post Mar 26 2017, 12:40 PM
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What if the cam lobe was gone for that valve? Probably wouldn't spring back like that though...
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iankarr
post Mar 26 2017, 12:54 PM
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Engine code stamp looks normal. And it appears the motor hasn't been dropped or worked on in a very long time.

I pulled the rocker assembly and the seat and setup looks perfect. Although the adjuster nuts were incredibly tight. I mean like insanely. Had to put the assembly in a vice to crack the nuts. Clearance was zero lash before removal, which leads me to believe there may be chromoly pushrods in here?

I pulled the #2 intake pushrod (pic below) and it appears fine and true. Any way to tell if it's chromoly?

When I put the rod back in, I feel it sitting in the cup as it should. Pushing on it definitely feels "springy". If I have to pull the tube and lifter I will...but I'd like to make that a last resort since there are no leaks now, and with things being undisturbed for so long, I'm not sure what might become dislodged. Also I don't know if there's any sealant in there that would be a b***h to clean without dropping the engine. But like I said...I will if I have to.

I'm going try to and contact the last long-term owner. I have his name and city. My yellow car had amazing records so it was easy to figure things out. This is like archaeology. Car-chaeology!
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Tbrown4x4
post Mar 26 2017, 01:08 PM
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You're this deep. I would pull the tube and fish out the lifter.

If some one put hydraulic lifters in our solid lifter engine, is there an oil gallery to feed them?
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iankarr
post Mar 26 2017, 01:21 PM
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QUOTE(Tbrown4x4 @ Mar 26 2017, 03:08 PM) *

You're this deep. I would pull the tube and fish out the lifter.

If some one put hydraulic lifters in our solid lifter engine, is there an oil gallery to feed them?


Of course you're right...It's always better to just rip the bandaid off and get it over with...

A picture says a thousand words. The question is...now what? switch to solid?

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Tbrown4x4
post Mar 26 2017, 01:32 PM
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I would switch to solid myself. I don't have a lot of Type 4 experience, but the hydraulics pump up at higher revs. That could be your power loss at higher RPMs.
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rgalla9146
post Mar 26 2017, 02:28 PM
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Maybe it's just that one ?.....best to check .... remove all rocker shafts and pushrods (as many as possible easily) not the return tubes just yet.
Buy or borrow a boroscope and check each lifter.
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