So my car just didn't feel right,slugish but not back firing or really running rough.
But not right....
Its 2.0 d jet

I pulled plugs and the last cylinder came up 40 psi low.....plugs looked good.
While doing compression test i noticed whoooooshing noise???
Did quick valve check and they seem ok.

I also noticed a exhaust leak sound while driving it but saw no sign of one?
Car sat 7 days w\o drive start and seemed to come out no where?
It used to rip!!!! Now not so much:(


Any help greatly is appreciated!!!!!!!
Thanks

Hole in the piston? You said you checked the valves or I'd guess a dropped seat...

Sounds like its pushing air out head gasket?

Hole in piston would b dead hole?
No compression.

unless it was a broken ring...

if your certain the fitting is making a good seal on the pressure guage..
sounds like you need to drop the motor

Wasn't there a thread awhile back where someone had a similar problem? It turned out to be a plug or something that actually goes into the combustion chamber had popped out.

good point George...

Scott, does this motor have late 75/76 heads on it?
it could be a blown air injection port
but they make a HECK of a racket on a running motor... you couldn't miss it if the motor was running. Loud

thanks for reply!
it runs just sounds like old bug while runing...
And it kinda runs on 3 cylinders when u start it cold until warm up?Which it didn't
do b4.
it's killing me I can't see where whoooosh is coming from.

I am still poking around

It's like blown head gasket?
Any body no what these cars run 4 head gasket?
I have never been in one of these motors but I think my time is coming.
Head gaskets go on these motors?
Thanks!

now that I think it through... the blown air injector wouldn't effect compression

so if your compression is down it has to be either:
a head gasket, valve, piston, ring, or other head damage.

the gaskets are metal rings, seperate for each cylinder
there is an ongoing debate about gaskets though

you would need to pull the motor for any of the above
once you strip the tin work off, you will easily see if the valve gasket is leaking and burning away your head material

depending on the mileage and rest of the condition... you can pull one head, fix the problem in that cylinder and reassemble

sometimes though this leads to rebuilding the whole thing once your in there....

Small squeaking whoosh is the head gasket, big whoosh see above....and hell of a racket whoosh is a blown spark plug.

Thanks buddy!!
I'll pprobably drop motor tomorrow. And post back.
120 ish psi on other 3 so I'll hope for best.

What's this picture of Mcmark???

Thank you!!!!

First pic is the head gasket area, on this head the gasket leak was ignored and the leak turned the combustion into a blow torch, cutting the head.

I'm, leaning towards a blown gasket because you can get 40psi, which suggests it's a "smaller" leak.

I get 80 psi stone cold on bad cylinder and 120 on others.
I think it has flat top euro spec pistons.

Thanks for your input!!!!!!!

If anyone has any advice for doing head gaskets "tips" I'd love to hear them.

Any recommendations on what head gasket to get and where to get the head gasket would b cool
too.

Should any other gaskets be replaced?
Should I buy engine reseal kit off ebay?

Thanks

Get a leakdown tester (aka. differential pressure tester) and perform a leakdown. You'll find out real quick where the problem is.

Air in crankcase - rings, piston, cylinder, head gasket
Air in exhaust - exhaust valve burnt, broke or adjusted to tight ( )
Air in intake - intake valve burnt, broke or adjusted to tight

I'd say get it dropped and disassembled far enough to see what's going on before ordering any parts.

Sorry for the quick hijack guys... Hey Brant, since I've never worked on a car with the later heads and the injector ports.. why wouldn't one of them being open, or patent, cause a loss in compression? They do lead directly to the combustion chamber, no? I agree that it's probably not the case here, as it would be a complete loss of compression as opposed to the OP's 40 psi difference. I do recall that in the other thread the person who posted it said that he could see visible exhaust flames escaping from the air port. Thanks for educating me buddy

they actually don't lead into the combustion chamber...
they inject air into the exhaust port right after the exhaust valve.
so they make a hell of a racket when they blow out....
but they wouldn't effect compression since its after the hot gasses have left the combustion chamber

brant

Aha! That makes sense! Thanks.

Well looks like a bad valve\valve seat....

It pukes air from combustion chamber into intake around valve seat.
Anyone ever see this b4?

Looking for good head shop in Denver Colorado.




Thanks to Ross for helping last night!!!!!

Is it a 1.7?
common issue.

He said it is a 2.0 Djet.

My '74 2.0 has what I believe to be a dropped seat as well. I still need to pull the motor to confirm.

GA case 2.0
Not sure what heads.

So do i replace valve recut seat and role on ?
120 psi on other cylinders......

Thanks

Dropped valve seat? I dont understand how valve seat can drop.
Looks like its not sealing?

Either way its got to go to head shop right?

Off to head shop.

He's saying 175.00 replace seat......

I just want to make sure its clear, the leak is DEFINITELY coming from in between the valve and the seat, where it should seal normally.

It looks as if it just isn't closing all the way (and the leak only seems to be coming from one side of the valve) Is that what a dropped seat looks like? Or could it be just a bent valve?

Not a VW head but this is a dropped valve seat

Ok, seat is definitely still in the head at least.

Seat is rocking\loose head guy said.
Replacing that loose valve seat and complete valve job on the rest them.
Hopefully back on road next weekend.

Thanks for the help!

The seat can be sitting in the head but still be dropped and when you take the valve out the seat falls right out. Usually this condition you see banging marks around the seat.

Lucky for me the seat just loose.

I've had three dropped intake valve seats on a 2.0 motor. One was just like that--the seat had obviously jumped out of the head, and been pushed back in again by the valve. The aluminum around the seat was fairly chewed up.

(The other two had come out and stayed out, though.)

Not all of these happened at once.

--DD

So u think I should have all the seats replaced?

Yes, have both heads done. Not only that, but spilt the case and have the rear 4 oil galley plugs tapped and plugged as well as the 2 in front above the oil filter console. atleast the engine will be reliable from now on. Easy for me to say since I'm not doing the work or paying for it, huh?

That might put me over budget but...........
I drive this car a lot so it might b worth it!!!!

Thanks everyone for advice! !!!!!!
I really appreciate it .