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Posted by: cuddyk Mar 26 2017, 09:25 AM

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!

Posted by: Tbrown4x4 Mar 26 2017, 09:29 AM

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.

Posted by: cuddyk Mar 26 2017, 09:33 AM

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

Posted by: Krieger Mar 26 2017, 09:47 AM

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.

Posted by: r_towle Mar 26 2017, 10:53 AM

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

Posted by: r_towle Mar 26 2017, 10:57 AM

Btw, that head is way to clean....

Posted by: Tbrown4x4 Mar 26 2017, 10:57 AM

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.

Posted by: stugray Mar 26 2017, 11:01 AM

QUOTE(r_towle @ Mar 26 2017, 10:53 AM)

Posted by: Mikey914 Mar 26 2017, 11:09 AM

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

Posted by: r_towle Mar 26 2017, 11:22 AM

QUOTE(Mikey914 @ Mar 26 2017, 01:09 PM)

Posted by: cuddyk Mar 26 2017, 11:28 AM

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!

Posted by: injunmort Mar 26 2017, 11:42 AM

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.

Posted by: Mark Henry Mar 26 2017, 12:16 PM

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.

Posted by: rgalla9146 Mar 26 2017, 12:16 PM

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 ?

Posted by: zipedadoo Mar 26 2017, 12:40 PM

What if the cam lobe was gone for that valve? Probably wouldn't spring back like that though...

Posted by: cuddyk Mar 26 2017, 12:54 PM

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!

Posted by: Tbrown4x4 Mar 26 2017, 01:08 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?

Posted by: cuddyk Mar 26 2017, 01:21 PM

QUOTE(Tbrown4x4 @ Mar 26 2017, 03:08 PM)

Posted by: Tbrown4x4 Mar 26 2017, 01:32 PM

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.

Posted by: rgalla9146 Mar 26 2017, 02:28 PM

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.

Posted by: cuddyk Mar 26 2017, 03:46 PM

Just checked the #2 exhaust lifter with the boroscope (cause I have every tool known to man. My garage looks like China.) it's also hydraulic.

The pushrods are magnetic,so I assume they're chromoly. But they look normal sized. I thought hydraulic rods were fatter? Could this be another episode in the adventures of DAPO???

Here's a pic of the #2 rocker assembly, but the rest look like this too. My yellow car had a McMark-built 2056, which had some pretty big differences...so I don't know what's "normal" for a "stock" 2.0. But I have read that spring rings like the ones on this rocker assembly are usually paired with hydraulic lifters...is that correct?

Now that the hydraulic cat is out of the bag, I def want to switch back over to solid. Problem is I don't know if the cam was changed and/or if it will work with solid.

Any suggestions on how to change it are appreciated... Will start another thread with specifics.

Thanks!

Posted by: rgalla9146 Mar 26 2017, 05:04 PM

QUOTE(cuddyk @ Mar 26 2017, 05:46 PM)

Posted by: r_towle Mar 26 2017, 05:16 PM

It could be fine if you let the oil get warm and fill up all the lifters again. No damage will happen, just lots of noise till the valves get warm.
If you want to check the cam, pull the oil pump and look for rivets instead of bolts where the cam is fastened to the cam gear. Stock is rivets.

Posted by: cgnj Mar 26 2017, 05:25 PM

CrMO for sure, Cam any ones guess. I"d go to solid lifter. Or is that injecting another problem?

Posted by: cuddyk Mar 26 2017, 07:03 PM

Thanks guys. Doing some research on conversion to solid now...

Posted by: Mark Henry Mar 27 2017, 12:03 AM

You absolutely have to change the cam to go to solid lifters.

Looking at the pushrods and lifter I can tell you I'm 99.9 % sure that it's an aftermarket hydraulic setup.
The .01 % is it could be a stock VW hydraulic cam with aftermarket lifters and PR's.

The solid steel spacer on the rocker shaft are stock VW hydraulic, keep them.
With the correct number of rocker shaft flat (thick) washers you can use them for T4 performance with 911 swivel feet, big cam, etc. Don't use the thin wave washers like in the pic for this, as they will break.
In fact I prefer steel spacers and consider the aftermarket aluminum spacers as cheap crap, because they wear too fast.

QUOTE(cgnj @ Mar 26 2017, 07:25 PM)

Posted by: Tbrown4x4 Mar 27 2017, 04:36 AM

I was more worried about new lifters on an old cam. I totally forgot about the different lobe profiles. I guess deep down I was hoping he didn't have to split the engine.

Posted by: cuddyk Mar 27 2017, 07:27 AM

Much appreciated, World.

If this is a cam change job, I'll probably drive it as-is this summer and do the surgery next winter. The car did drive great with the exception of the occasional hesitation at 3K. Hopefully the dizzy cleaning took care of that. And it's still the original case, so I guess I got that going for me. Which is nice.

Posted by: cuddyk Apr 1 2017, 11:22 AM

Just a quick update...

Turns out the rough running was due to a bad spark plug cable (old school NGK with cracked shield). The pertronix is rock solid and the noisy hydraulic lifter pumped up with oil and quieted down after about 5 minutes of driving. All great now. Nice to know I don't have to split the case right at the beginning of the season.

Thanks again to the great engine forensic detectives!