Mystery oil leak into top end rebuild

[ac78]

I put new AMC heads(non-HAM) on a couple years ago but have been plagued with an oil leak that was coming for the 3/4 side. I have been replaying when i torqued the heads because at the time, i wasnt convinced my torque wrench was calibrated properly. I have been wondering if I had a loose head. I did install new pushrod tubes with viton seals. I have been having to replace my valve cover gaskets too frequently. On a long trip last year I even had oil come through the fan shroud up by the coil where I started to suspect my oil cooler gaskets blew and the fan was blowing oil in places it shouldn't be.

I just got it on the stand today and mostly undressed. My flywheel was dry as a bone so I expected to find oil all over the oil cooler, but nothing there either. I don't have the fan shroud off yet because I ran out of weekend... I'll get some pics up of my progress next weekend.

I did want to ask 1 question. Is a leak down test on a cold engine worthless? I figured it's still good for the valves but not sure about the rings.

Thanks for your help!

The silver lining is that since I have it this far torn down, I'll go ahead and replace the heads with my HAM heads I've been sitting around for just such an occasion..
_________________
78 Westy 2.0l hydr. FI

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

[aeromech]

If your heads were loose you’d hear it before seeing oil. Gallery plugs can leak. Oil pressure switches often leak. You should have use UV dye and. Black light before you pulled the engine.
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[ac78]

[aeromech]

I assume you can run it on your stand?
_________________
Lead Mechanic: San Diego Air and Space Museum
Licensed Airframe and Powerplant Mechanic
Licensed Pilot (Single engine Land)
Boeing 727,737-200-300-400,757,767
Airbus A319,320,321
DC9/MD80
BAe146
Fokker F28/F100
VW type 1 1962,63,65,69,72
VW Type 2 1971 (3 ea.) 1978, 1969
VW Jetta
VW Passat
Capable of leaping tall buildings in a single bound

[SGKent]

you mentioned valve cover gaskets frequently. The newer ones are thinner, while old stock are hard and less pliable. Put the covers on each head with the seals off and see if they rock. If they do the covers are tweaked. That was the cause of why mine were leaking. Tweak them back until they don't rock.
_________________
“Most people don’t know what they’re doing, and a lot of them are really good at it.” - George Carlin

[aeromech]

I believe high breather pressure can cause valve covers to leak
_________________
Lead Mechanic: San Diego Air and Space Museum
Licensed Airframe and Powerplant Mechanic
Licensed Pilot (Single engine Land)
Boeing 727,737-200-300-400,757,767
Airbus A319,320,321
DC9/MD80
BAe146
Fokker F28/F100
VW type 1 1962,63,65,69,72
VW Type 2 1971 (3 ea.) 1978, 1969
VW Jetta
VW Passat
Capable of leaping tall buildings in a single bound

[ac78]

[Spike0180]

[ac78]

sorry, just found me original thread...Finally got some time to tear down a bit today. I've had been experiencing a pretty good oil leak and an oil light flicker on long drives. I'm interested in your feed back on my cold leak down results and pics from when I removed the heads.

I removed the rockers and the cold leak down gauge results are as follows:
#1- 100lbs- 100lbs
#2- 100lbs- 98lbs
#3- 100lbs- 100lbs
#4- 100lbs- 98lbs

That made me feel pretty good until I removed the heads. #3 and #1 had some oil in the cylinder. The pushrod tubes seemed clean. The oil cooler didn't look like the culprit. The clutch side of the flywheel looked good but It sure looked like the block side could have been slinging oil through the hole up onto the heads. Based on the oil in the cylinder, It looks like I have an issue with the rings. What do you all think?

_________________
78 Westy 2.0l hydr. FI

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

[timvw7476]

Could that oil in the cylinders come from being shifted around after
removal? Thinking a welch plug may be ready to let go on the flywheel side.

[71whitewesty]

I’m not sure on the oil but your thermostat looks shot.
_________________
71 Westy 1600 DP, all stock Bus 1
1970's Snow Trac 1600 SP (sold 12/2016)
1968 Tucker sno cat, sold 2021
1969 Tucker Sno cat 542
2017 VW Alltrac
71 tin top stock 1600 DP (project but runs)
Twin 71 White Westy, Bus 2, that I pulled from a 15 year slumber in a dry eastern WA field in 2015.
1966 Sundial Camper "Boomer"

[Wildthings]

Excess blowby and an old hard o-ring on the distributor can get you oil on top of the block. I think you have excess blowby no matter what, though. It looks like the cylinders were honed very recently so I wonder if the compression rings were installed upside down or something??? Pull the cylinders off so that you can run a hone through them and seal the base of the cylinder to the block with high temperature silicone or other goo. Buy new rings and a rebuild gasket set and the two crankshaft seals. Do check your galley plugs carefully and peen around them if this hasn't been done before. This is not needed if the press in plugs have been replaced with threaded plugs.

Check for how much side to side movement the valve stems have in their respective guides.

[ac78]

[ac78]

[SGKent]

my eyes say that there is a ridge on the cylinder so that means wear. The heads are warped. To my eyes that say the engine is getting tired. The pistons don't show problems with oil control so it might be from the guides. If the piston rings were worn, the oil washing over the rings would leave a clean area around the outside of the pistons (unless you are using a non-detergent oil). Go back and look over the photos for what I am describing.

_________________
“Most people don’t know what they’re doing, and a lot of them are really good at it.” - George Carlin

[rastomas]

I believe #3 and #4 cylinders are marked wrong.
_________________
"It's not 'You are what you eat', it's 'You are what you don't SHIT". Wavy Gravy.


'74 Westy

[71whitewesty]

[rastomas]

Yes, they're correct. Momentarilly photo-dyslexic.
My bad.
_________________
"It's not 'You are what you eat', it's 'You are what you don't SHIT". Wavy Gravy.


'74 Westy

[ac78]

[Wildthings]