Some of you may have read my earlier pleas for help when my engine suddenly would not start. I thought it was the FI but after following the advice of members I did a compression and leak down test and discovered Zero compression and 100% leakage on #2.
With a heavy heart I pulled the engine, the pictures say it all.
I had the heads rebuilt earlier this year and have not done more than 300 miles.

Some questions:
what else needs to be checked for damage?
I need some new heads does anyone have some ready to use heads for a 75 2.0?
I guess the piston is also unusable, if I get some aftermarket P&C can I just install them without replacing the bushings on the connecting rods?

I guess the summer will be over before the engine is fixed.

Aow that really sucks

Looks to me that you should get the valve seat replaced, buff out the dimple in the piston and get back on the road for the remaining three weeks of your summer....then do more extensive work later.

I would like to think that the piston is okay....but that's the optimist speaking

Any chance the piston could be cracked or any damage to the rod or crank?

If the piston was soft enough I guess it could absorb the worst of the impact without transferring that shock through the rest of the motor?

What a bummer, but at least you are going for it!

Good luck with the rebuild!

Oh no! That sucks beyond belief. I hope damage was minimal and is contained to just the head and piston top.

The pistons take a much worse pounding with each compression stroke than felt by that small ding. As long as timing, mixture, ..... thermostat,..... are all set correctly, you can just leave the P/C on, buff the top of the piston and get the heads done correctly. That problem if not initiated by some of the above wrong settings, is due to a bad valve job.

Spend the money and get them (do them both to avoid this problem again) done right. Here are the folks that know how and have worked with 914 heads and development of new heads for a very long time.

Hoffman%20Automotive%20Machine,%20Inc.%20-%20VW%20Type%204%20Heads.webarchive.

If link doesn't work, just look up "Hoffman automotive machine"

That doesn't look so bad. Head can be saved.

After 300 miles? That's a valve seat that wasn't installed correctly in the first place. And for it to happen on that cylinder just means the rest weren't far behind. Ditto on doing both heads.

I suggest going to where you had them done and dropping them on the counter asking WTF? The last mechanic that f'd up one of my vehicles paid half the bill for someone else to do it right.

When rebuilt was the seat replaced?

Seat looks odd, not only dropped, but also like it's broken.
I agree that both the head and piston may be savable.

The piston is good, just buff the top.
The head needs work. If the valve seats were replaced, then the guy who did them did a bad job. If they were not replaced, did anyone checked them before assembly? A failure in 300 miles means that the seat was not fixed good at assembly time.
If you need, I have a 2L head. I can send it to the local guy that did my heads and was top notch.

Some here have pretty good observation skills to assume the piston is okay ("It'll buff out"). The hit was toward the periphery of the piston and the impact could have affected the ring lands below it. Have you inspected the piston yet and the resultant ring side clearances? If affected, the ring might be seized and thus unable hold compression to spec. But I'll admit, removing a piston is yet another stage in engine disassembly.

You could also just repair the heads and reassemble, but perform a compression test on the bench to confirm all is okay.

MHO

The piston crown is designed to take much abuse. Shock waves and compound standing waves from pre-ignitiion. That is a small dent. I have seen MUCH, MCUH worse damage to piston crowns were seat went to shrapnel and embedded in piston crown. Piston and ring land still perfect.

Good advise though to take the barrel off and inspect the piston if for no other reason than it is easy at this point and will give peace of mind to confirm it is completely OK

NOTE: Cracks start at the surface, so the smoother the transitions are made when buffing the stronger the crown will remain.

IMHO

.......................unless the pins holding the rod to the piston was weakened and separates from the piston under some stress/overrev and then ?

The piston pin is THE most robust part of the entire engine other than perhaps the flywheel !

Here is a close up of the Piston. The damage is about 2mm deep at the deepest point.
Many have said that this will buff out. Is it just a case of smoothing the edges to the damaged area, what do members think is the piston usable?

If the lands are not damaged then blending the edges of the damaged area to reduce the chance of preignition is in order and by the looks of the pic it appears that it will be ok. No need to "buff it out" but blending yes

_Robert

Buff?
Nah,Pull the cylinders,check the rod for bending,rod bearings for damage,rod bolts for cracks,crank for damage.
A hole in the crankcase may result otherwise.

Send BOTH HEADS to Len at HAM. One intake seat came out; the others will be relatively soon. Don't ask how I know this.

--DD

Safe way: check everything
Fast way: leave the cylinder alone

The gouge in the Piston is nothing. Don't even think about that. You don't run high enough compression for it to matter. There is very likely no damage to the rest of the components. But realize that there is some risk to ignoring it.

Wasn't this already suggested ??

I've had worse looking pistons. I had about 70k miles on an 1835 T-1 motor that busted an exhaust seat - just checked the rings and replaced the heads. I sold the car when it 175k on the motor and it still ran great.

I agree, take the heads back to the shop that originally did the work - they might fix that Pro Bono

I gave one shop three chances at that. I finally used a different shop, and somehow or another the seats stopped dropping...

--DD

There is a chance the rod is now slightly bent. Skip checking that and you may end up doing the motor again.

Shipping a set back and forth will cost a fortune. No telling how customs are going to see it.

I didn't see where he stated where he had the heads done - just figured it was local to him

See post #1 mark.

I know my eyes have gotten worse over the years, Kev, but not that bad.

Still not seeing where the heads were reconditioned

The heads were rebuilt locally in Gothenburg Sweden. I asked if they knew about air cooled motors and they assured me they knew what they were doing obviously they didn't.
The shop is closed (summer holiday) until August. I will return both heads and see what they say. Even if they agree to replace the valve seats (4 were replaced on the rebuild) I don't have any confidence in their work. I got hold of some used heads from a member and they are on there way from the US. These heads should be ok to get the car running for whats left of the summer
You guys have it good your side of the pond, parts are readily available and machine shop costs although not cheap are a lot more reasonable than Sweden.
Unluckily for me the dollar has gone through the roof so imported parts are getting expensive plus theres 25% import duty on the part cost plus the shipping costs. I hate lying to the wife when she asks me how much this engine rebuilt has cost.

Agree with taking them back for a refund, but NOT work/rework. If the person repacked parachutes, would you go back ? Not likely. Get as much money back as you can.

The used heads you have coming have many advantages to yours reworked (by anyone) as many have already suggested. I want to add my 2 cents:

The used heads have already been thermal cycled many, many times and are still OK (assumption here) based on the seller and you agreeing they are "good heads". So, the chances of a seat failure are unlikely if all other aspects of your engine running are as they should be. This option for you seems like the best based on the information you provided to the Board.

Here is my 2 cents: Remove the valve keepers and spring(s) from each of the four exhaust valves prior to installing. Push the exhaust valve open with your finger about what the cam would when installed. Then, rock the valve face perpendicular to the valve shaft back and fourth, then move your fingers 90 degrees and repeat. If the valve rocks about 3 mm to each side, you need guides and will most likely have smoke when you lift as the intakes will also be worn only not as much. Installing Silcon Bronze guides and hand lapping the valves (your self) will buy you some time with the used heads. If the rocking of the valves is less than the above, you are good for many, many carefree miles.

Spend the time enjoying your used heads saving to have your original heads done up right by the folks I and several others have recommend as the heads are the key to the 2.0 engine long life and performance. Spend the money on heads as the stock bottom end is nearly bullet proof when taken care of.

Hope this helps. CJ

I pulled the head for #3/4 this afternoon and got more bad news. The intake valve seat on #3 had dropped. The piston has hit the intake valve and broken the rocker arm.





I found a Rocker arm for a type IV it has the same part # can anyone say if its the correct part for a 2.0 76?

Help much appreciated as I am beginning to get a little disheartened

Crap ! In this case, the push rod is almost for sure bent. It usually pays the price for the rocker, but not in this case ! You must check the push rod too.

You really need to have a chat with your head guy....

When did you last adjust the valves? Did you have a big gap on the valves that broke?
If the seat dropped, I would expect the valve to remain down and hit the piston but what caused the valve to not open at all or go up when the camshaft lobe was closing it and brake the rocker?
Is your camshaft correctly aligned to the crankshaft?
What camshaft do you have?
Can you push open the valve that broke the rocker?

RE: rocker arm - there are 2 types: 8mm and 10mm diameter. You want the 10mm for the 2.0L. I'm not sure what size is the one you found. Those are available used and you could also use a 8mm one if you get the right adjuster for it.

**EDIT** that is the correct 10mm size for your 2L.

I see your point. I am running a stock cam. Perhaps the rocker failure and the seat failure are not connected? Everything was aligned and the valves adjusted to spec.
Anyone got any ideas?

Interesting that you didn't see low compression & leakage for cyl #3 as well during your initial testing.

Were the heads assembled when you received them? ... or did you reassemble them?

Wondering what the 2 valve stems and guides look like ?

While 2.0L heads do flow better, they also have a history of dropping seats.

Did you notice high engine temperatures anytime during that 300 miles?

I did not do a compression/leak down on # 3, I pulled the engine after seeing the result for #2
The engine never ran hot and the heads were delivered assembled. I do not want to dismantle the heads to examine the vale guides etc before I return them to the shop.

Can you push open the valves that broke/bent the valve train?

When you say push open do you mean by hand or with the use of a tool?

Heres what it looked like when I removed the valve cover, to quote another member "people like carnage"

If the seat begins to drop (from your pic lets call it 10mm) then the valve cannot move all the way back to where the rocker was set for lash.

So now instead of .006 valve lash you now have 10mm valve lash.
The rocker will bang around in there as the seat drops until the pushrod jumped out of the cup.
Not surprising that the rocker arm would take a beating.

That makes sense. Thanks

Makes me wonder what the shop did wrong that the seats would drop like that.

Don't know enough about the process. Hope you find a shop that can get it back together for you.


Dave

The shop that rebuilt my heads opened today after their summer holidays so I paid them a visit taking the heads, each with one dropped intake valve seat.
According to the shop it was either the timing that was out or over revving the engine that caused the seats to drop. In other words it was not due to a bad workmanship, it was apparently my own fault.
Things got a bit heated on there part when I stood my ground and declared it was down to them.

What do members think could timing or over revving cause the seats to drop? I never revved the engine over 3500 and I was careful to set the timing to spec.

No, the shop owner is a lying liar.

Some shops have no idea how much interferance fit is required for new seats,or for that matter how to remove them correctly,appears to be the case here,sorry to see this,what solution have you reached with them?

I would say to post the name of the shop.....but given it is in Sweden, I am pretty sure he won't be receiving any work from the U.S. and I am pretty sure you got the club members of in Sweden filled in to prevent any future such incidents.

I hope you can get it repaired and running for a reasonable price.

I don't see any signs of massive overheating on those heads. I suggest to get a second opinion.

Either that, or too clueless (and refusing to admit it) to be working on aircooled engines.

--DD

You did nothing wrong. They fucked up and won't admit it. Keep pushing them.