EDIT: Thread was "How can I tell if my aircooled has a cracked head?"

Hi there. I'v been searching the forum, but haven't found the answer to my question.

I believe my van may have a cracked head but I'm not sure.

It has been off the road for maybe 8 months now due to a sudden loss of power and this nasty squeak-squeak-squeak, which sounds close to a clunk-clunk-clunk when the engine runs a little faster. If I can get it started that is.

The engine turns fine with a spanner. No sign of the squeak when being hand turned.

I just pulled off the left carb (the sound was coming from that side) to check for metal filings. Nothing.
There is no trace of metal in the pressure equalisation tube either.

The spark plugs are uncontaminated. No filings or oil.

The valve clearances are spot on still too. So it is less likely that it is a stuffed valve seat.

There is compression on 3 (not sure how much. Used finger), Couldn't test 4. Fingers too short.

Okay people. What do I do next? Is there anything else I can check to diagnose the problem before I pull the head off?

I'll be removing the head without dropping out the engine. I don't have the equipment or manpower to get the engine out or in by myself.

So, What now?


[Edited on 25/4/2005 by General_Failure]

[Edited on 25/4/2005 by General_Failure]

are you sure the head isnt loose ie pulled head stud

Unfortunately, the thought of a pulled stud or studs has occured to me too. I guess the easiest way to check that would be with a torque wrench. If my motor did do a stud pull, how can I fix it? Preferably without removing the motor. I should be able to get the head and cylinders off without removing the engine...I think.

Is there any blood? last time I had a cracked head there was blood:duh

Just an addition to that. Shortly before the engine stuffed up, I had to rebuild the topend on both sides because of a dropped valve seat. While I was at it I replaced a head, 2 pistons, most of the rings (2nd compression rings in the kit were all out of tolerance. Wouldn't fit in the ring grooves), cylinder base gaskets, head gaskets, inlet and exhaust manifold gaskets.
When I did up the left side (3&4), I did feel a little bit of doubt about the studs. They tightened to spec, but it took a little too long for my liking. EDIT: replaced 1 or 2 barrels too. Don't remember exactly.

I hate to ask, but what about helicoils? Case savers need the engine dismantled to drill out the stud holes, don't they?

EDIT: Waaait a sec. Wouldn't the valve clearances be out if I pulled studs?
I admit. It sounds like pulled studs. Crud.

Was reading in another thread about self tapping studs. Is it worth it. And if so, where would I get them?

[Edited on 25/4/2005 by General_Failure]

Sure, I'm replying to my self. Anyway....

Where can I get self tapping studs? ...Surely someone knows. Anyone?
Google's given me nothing useful.

every shop should have self tapping studs. try mick motors or other big name shop, they have everything.

i had an old beetle with a pulled stud which i didnt work out was a pulled stud intill i'd taken off the rocker gear & tightened for the thrid time (i blame mum and drugs in the 60s). couple of tapping studs and it torqued down fine (although i didnt cane it afterward). i sold it to some dude as a baja project a coupla thou km later...

So they are fairly common then...

If I use them, my only option later on would be case savers, wouldn't it?

The van's engine has never liked me. Bloody 1800. Dunno how many roadside repairs I've done. People wonder why I carry 2 large toolboxes and a mass of spares...

As long as it's tapped properly, it should stay together on the slightly brutal side of normal use, right?? Basically the occasional knock it back a gear and floor it to overtake. And towing/heavy load. Never did get a chance to see if I fixed the overheating prob either. Got 60km after my rebuild before it carked it again.

Thanks for your help so far everyone.

A stupid question. when I get the symptoms, does it mean all the studs are pulled? And is it possible to rescrew the studs into the case successfully ever?

if your motor is a tpye 4 i doubt very much that you have a pulled head stud ...ive never seen one in 25years...if the prob is occuring on the 3/4 bank the chances are the head gasket is blown..that is the thin metal gasket between the barrel and head...this a common prob with high mileage type 4 and reco cyl heads.if that bank has run lean..chances are the brake booster sleeve is perished at the balance and sucking secondary air..this in turn leans ot 3/4 cylinder which runs very hot and starts to blow the head gasket..the tell tail sign is the signing budgie at idle..it may have damaged the piston skirt and barrel due to the servere overheat therefore a more metallic noise is emmitted.....what fuel have you been running ? what is the compression ratio as some 1800's had 412 pistons fitted with a dome on top to increase hp therefore dangerous compression ratio...is it driven on open roads alot..invest in a air fuel meter to avoid lean out at higer cruise speeds..dont thrash a air cooled engine at high abient temps its like trying to jog in a sauna..keep your compression ratio low ie between 7-8:1 is a safe bet for kombis..cheers dsk member

hey, rhddlxbd. Your knowledge brings me enlightenment.

I thought those bloody 412 pistons were work-alikes! I just figured it was a redesign (or an earier design). I used them as replacements.

I can tell you, the vacuum lines, including the booster line are fine. ages ago I had trouble with the brake booster L-sleeves. Werent perished, just stretched. a couple of hose clamps did the trick.

when outside temp is high, i usually kept speed below 80. Did the same when towing or moving heavy loads.

the problem occurred instantly and catastrophically. Lost power a few hundred meters before home. coasted there pretty much.
After that it could barely move under its own power. I could just get it rolling on flat ground. This was to get it into the shipping container because it died a few days before moving interstate.

Because LRP was unavailable where I was, I was running PULP and that valve lubricant stuff. Oddly enough though. I saw 2 other cars die after getting fuel from that particular servo.

It was driven on open roads all the time. Originally up and down the blue mountains and great divide, and then along flat-as-a-pancake QLD. Now it _would_ be city traffic, if it were running.

I didn't know I could use an air fuel meter on it! where can I get one?

Going to try to get a compression gauge in the next few days to test.

Still worried about pulled studs though. There's always a first time. I'll be checking them with a torque wrench in the next few days.

Thanks again!