Mystery sucking/swooshing sound- constant

[ac78]

Hey all-

I have a 78 2.0l hydr FI with a constant sucking/swooshing sound around #3 and #4. I did a compression test #1-124 #2-128 #3-104 #4-122. I have a good battle with vaccum last year so I know this is different. I was looking into adjusting valves since it hadn't been done in 12,000 miles. Just tonight, I was hand turning and when I got to #3 there was little resistance and then Hissss. It was not a fluke, I kind of rocked it back and forth hissed every time. Very slight hiss through #4 and normal on 1 &2. Seems to be below the top tin, toward the top of the cylinders. My hunch is that the motor is going to have to come out to resolve whatever the problem is. Only problem is I have never taken one out. I am up for the challenge though, with help from my Bentley, Muir and Chilton and Bug Me/Raby video. Also surprised #3 compression is that high with this big a leak.


What do think it could be? Head? Cylinder? open Valve?
Thanks for the help!
_________________
78 Westy 2.0l hydr. FI

VW Campmobile
For people who believe a family's
car should be it's castle !

[73kombi]

Was it just the intake "swoosh"?

Maybe intake gasket?

I like that noise....let's me know the cylinder is "in-taking" fuel....

Compression seems fine.

[ac78]

When hand cranking, it seems to come from the center of the cooling tin, forward and left of the dizzy. I just got back from using my vaccum tube stethoscope and that's as close as I can get. When you hand crank the others cylinders, there is a lot more pressure and no hiss.

I just took it out and heard some pinging when I mashed it. I forgot to mention that in my orginal post. (It's been a while since I've taken it out of the driveway, since I don't trust it right now.)

http://www.youtube.com/watch?v=t4Z7mgHBttw
I was trying different spots, it's more noticable in the last 15 seconds.

http://www.youtube.com/watch?v=3n3mOOFPovc
hand cranking
_________________
78 Westy 2.0l hydr. FI

VW Campmobile
For people who believe a family's
car should be it's castle !

[Jake Raby]

Head leak.
Probably another wonderful blown head gasket.
_________________
Jake Raby
Raby Engine Development
www.rabyenginedevelopment.com
"I've never given anyone Hell, I just told them the truth and they thought it was Hell"

[ac78]

This is just the motivation to fix a couple leaks too. If it is just the head gasket, do you think I could get away with just removing the gaskets and then reinstalling the head without the gasket? Also, probably a stupid question, but, should my compression come back up like the others?

I have read though the engine removal chapters several times in all my manuals and I am hung up on the support bar for the transmission. Bentley Chapter 5/Page 9/ figure 3-8 says support the end of the transmission that is farthest away from the engine. The picture doesn't look like the farthest point. When I look under the bus, it seems like it would need more support on the end that is closer to the engine. Am I just not understanding?

Thanks for your hlep!
_________________
78 Westy 2.0l hydr. FI

VW Campmobile
For people who believe a family's
car should be it's castle !

[Jake Raby]

Onve the combustion chambers begin to have a leak the surfaces of the head and cylinder are compromised. These must be checked and intervention performed.

I have seen heads melted at the sealing surface due to those stupid gaskets.

Don't expect to just bolt it back together.
_________________
Jake Raby
Raby Engine Development
www.rabyenginedevelopment.com
"I've never given anyone Hell, I just told them the truth and they thought it was Hell"

[ac78]

Thanks Jake! We'll see how bad it is once I get it into it.
_________________
78 Westy 2.0l hydr. FI

VW Campmobile
For people who believe a family's
car should be it's castle !

[USMCbug]

Would a leaking head gasket compromise compression? It looks like his compression was good unless its a very small leak at the head gasket. How about an exhaust leak?
_________________
72 Super Beetle
73 Standard Beetle
79 Baywindow Bus
65 Split Window Bus
79 Baywindow Bus
71 Super Beetle (current)

"When war does come, my advice is to draw the sword and throw away the
scabbard."
- General Thomas "Stonewall" Jackson

[Jake Raby]

It may not, especially if the compression checks were done without the butterfly at WOT
Thats because the chamber isn't being filled thoroughly enough to show the differential..
_________________
Jake Raby
Raby Engine Development
www.rabyenginedevelopment.com
"I've never given anyone Hell, I just told them the truth and they thought it was Hell"

[ac78]

I don't mean to sound stupid here, but what is the butterfly and the W in WOT- W... Operating Temperature? I did run the motor for about 15 minutes before the test. I don't mind doing it again to make sure it is done properly.
_________________
78 Westy 2.0l hydr. FI

VW Campmobile
For people who believe a family's
car should be it's castle !

[udidwht]

Wide Open Throttle = WOT

The butterfly is fully open when WOT.

[ac78]

Should I do another compression test with a brick on the accelerator ? or just keep preparing to pull the motor and test again after it's fixed?

I am feeling confident I do need to pull the motor to see what's going on, even if I may not have done the compression test properly(Although I did it based on Muir's book)
_________________
78 Westy 2.0l hydr. FI

VW Campmobile
For people who believe a family's
car should be it's castle !

[Rusty O'Toole]

You need to take the head off immediately. Driving will only make it worse. At this point you know that you have leaky head gaskets. But you also know you caught it early, before the sealing surfaces got burned real bad.

It may be possible to fix it without too much trouble. The only way to know for sure is to take the head off. If it gets real bad you will have to replace the cylinders and head.

[SGKent]

Check to be sure all the spark plugs are the correct tighness then do a leak down test if you want to know before tearing it down, however all the likely candidates excepty a loose spark plug will require the head(s) come off.

blown cylinder head to cylinder
cracked head
burned valve
loose valve seat
_________________
“Most people don’t know what they’re doing, and a lot of them are really good at it.” - George Carlin

[ac78]

I have to admit I was intimidated by the task. Well, I finally summoned the courage to drop the motor. Yes it's been a year and a half, better late than never! Thank you Ratwell for your 20 step procedure!

You kinda start grinning at the first sign of seperation. After another 30 minutes of wiggling and jacking, words just couldn't describe how I felt when it was completely out!

http://78vwwesty.shutterfly.com/pictures#n_5

Now I have alot more to discuss:
I managed to break the 1st fin on both cylinders.
The cylinders were pretty oily and a decent pool at the bottom.
There is a hole in the #3 head.( Found my swoosh!)
There was a spacer on the head, but what is the stuff on the bottom of the cylinder? Is that what's left over from the original paper gasket?

I have $850 budgeted. Is that realistic for an overhaul?
Head- I was hoping it was okay, but sending for rebuild, if needed. Now that there's a hole, is it junk and need new?
Pistons and clyinders??
Rings without new pistons
Used cylinders?
Other seals etc that are easy to get to now.
The only other thing I was going to do was the FI hose kit from German Supply.

Thanks for your help?
_________________
78 Westy 2.0l hydr. FI

VW Campmobile
For people who believe a family's
car should be it's castle !

[Wildthings]

The hole in your head is interesting as the seat doesn't appear burned through. I wonder if there were a thin spot in the casting? Your need to check ring land clearances on your pistons and see how much wear there is at the top of the ring travel on your cylinders.

[SGKent]

interesting. Color does not show lean, oil burning is a little there but acceptable still, no sign of physical object on piston, no sign of detonation, valve seat is seperating but not dropped. Maybe a crack in the casting that allowed leakage around the seat or a bubble in the casting that failed. Maybe someone welded it and the weld had bubbles in the work. I would replace the one head, redo both at RIMCO or Headflow Masters - don't know if I would trust welding the bad one in case there are more flaws in the casting, and consider new cylinders, pistons and rings since you broke the fins. Always a shame to have an engine down so far and not go all the way thru it but $800 won't go very far on a T4. Rebuilding a set of heads is about $1000 and a set of mahle pistons and cylinders will cost about $350 - $400. Gasket set is $70 or thereabouts. That assumes you don't find anything else wrong.
_________________
“Most people don’t know what they’re doing, and a lot of them are really good at it.” - George Carlin

[ac78]

I had some questions about the TSB for the 2.0L after reviewing the heads and cylinders(pictures):

No. 2 Eliminate aluminum seal 021 101 341A between cylinder and cylinder head. Is this the aluminum shim that I took out of the bottom should not be there, correct?

Any ideas on what the flakey material is at the bottom of the cylinder? Is that residue from the original paper gasket?
No. 3 Eliminate paper gasket 021 101 341A between foot of cylinder and crankcase.

No. 4 Install 1.6mm aluminum shim 071 101 341, with adhesive D 000 400 at foot of cylinder to compensate for removed paper gasket and aluminum seal. Where do you get this adhesive?
_________________
78 Westy 2.0l hydr. FI

VW Campmobile
For people who believe a family's
car should be it's castle !

[ac78]

After thinking about this hole, it dawned on me that 3 years ago I took the camper in for service, oil change overall checkup etc. They told me I had a loose stud for the exhaust manifold. I knew that, but didn't think it was that bad. I went ahead and said yes to having them fix it because they were a shop and had access to all the tools, right? They ended up having to "Drill out" the stud. I have now learned they used a little too much shoulder. The blew through into the head, that's why the puncture is jagged by the valve. If it had come from the inside, the hole would be smooth.

I believe the stud was stopping most of the air, but was leaking out the other hole that was on the outside of the manifold. That's why my compression was still decent. What do you guys think? I added some new pics of my findings.

http://78vwwesty.shutterfly.com/pictures

Can anyone tell me if this head would fall under the Headflow Masters $325 rebuild? Or am I screwed and have to get a new one? Any of you have leads on cheap a rebuildable 2.0 L head?
_________________
78 Westy 2.0l hydr. FI

VW Campmobile
For people who believe a family's
car should be it's castle !

[SGKent]

you would have to send the head to Adrian or RIMCO and ask them if they could fix it. That valve seat is starting to fail also - look at the gap on the right vs left.
_________________
“Most people don’t know what they’re doing, and a lot of them are really good at it.” - George Carlin