Engine Oil Leak on bottom of cylinder head nearest driver

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Jimm391730
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Re: Engine Oil Leak on bottom of cylinder head nearest drive

Post by Jimm391730 »

Yup, it's been discussed, Jim L in fact has pointed out that our Pinz engine is designed to have a "small" degree of oil flow past the valve guides. This will result in Synthetic oil burning in the chamber leaving a really crappy residue
build up. That stuck in my head as a don't do ever.
OK, I agree that oil does not typically burn as clean as gasoline (with all the additives in the oil) but with all due respect to Jim L, most modern two stroke engines REQUIRE synthetic oil (specific to the application, not normal motor oil) to be mixed with the gasoline. I am not convinced that synthetic will burn any differently than dino oils. I went from a Pinz engine that burned a quart every 3-400 miles to a Jim L. rebuilt engine that consumes a quart every 1-2000 miles (and most of that is lost through leaks!). So the consumption through the valve guides should not be significant. I'm sure Jim has seen fouled plugs but I am very suspect that the root cause of fouling is due to synthetic oil.

However, my opinion isn't important. I appreciate Ron finding the link, so I know what I missed.
Jim M.
712W and 710M
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waterdog
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Re: Engine Oil Leak on bottom of cylinder head nearest drive

Post by waterdog »

i dont think its the valve cover gasket............i read somewhere about that kind of leak....and it was coming from somewhere else...
1985 710MS
1985 712MK
1988 PAJERO CAMEL SPECIAL 042/150
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Jimm391730
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Re: Engine Oil Leak on bottom of cylinder head nearest drive

Post by Jimm391730 »

Leaks can often be at the pushrod tube seal, but from the photos and to leak onto the exhaust manifold I agree that it is most likely the valve cover seal. The straight sides of the rectangular gasket get sucked inwards (I would think that the inside edge of the gasket swells, being in contact with oil and fumes, and if the ID of the gasket edge gets longer then it bows inward). This is a good reason to glue the gasket to the valve cover, plus this makes re-assembly and the occasional valve adjustment much easier.
Jim M.
712W and 710M
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rmel
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Re: Engine Oil Leak on bottom of cylinder head nearest drive

Post by rmel »

Two part reply :D

First, on engine oil, Jim, why don't flip over of Synthetic and report back after 5,000to 10,000 miles and let us know how that worked out :mrgreen:
I actually use aviation grade oil ratted for air cooled and is tuned for better heat transfer properties through an oil cooler. I'll stick with that :)

Leaks, man do I hate leaks. I too lose about 1 quart every 1,000 to 2,000 miles, and that ain't from burning it. In my case
it's behind Cylinder #3 and specifically the push rod housing gasket, there are a pair of push rod tubes that go into that housing, each with two
domed rubber grommet type gaskets and two more gaskets at the opposite end going into the head. A 3'rd tube at the bottom is the oil return, for
a compliance fit, the head end has a o-ring. If it's not the valve cover gasket it could be one of 6 washers or the housing gasket. Pray it's your valve
cover because if it's one of these other parts it's major surgery and not a DIY job less of course you know the tricks.

IF you already confirmed oil at the bottom of the vavle cover consider yourself a very lucky -- hopefully :wink:
Puller: 71' 710K 2.7L EFI aka Mozo
Follower: Sankey MK 3, 3/4 Tonne
Rescue Pinz: 73' 712MK

Driver: Ron // KO0Q
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bbolander
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Re: Engine Oil Leak on bottom of cylinder head nearest drive

Post by bbolander »

rmel wrote:Two part reply :D

First, on engine oil, Jim, why don't flip over of Synthetic and report back after 5,000to 10,000 miles and let us know how that worked out :mrgreen:
I actually use aviation grade oil ratted for air cooled and is tuned for better heat transfer properties through an oil cooler. I'll stick with that :)

Leaks, man do I hate leaks. I too lose about 1 quart every 1,000 to 2,000 miles, and that ain't from burning it. In my case
it's behind Cylinder #3 and specifically the push rod housing gasket, there are a pair of push rod tubes that go into that housing, each with two
domed rubber grommet type gaskets and two more gaskets at the opposite end going into the head. A 3'rd tube at the bottom is the oil return, for
a compliance fit, the head end has a o-ring. If it's not the valve cover gasket it could be one of 6 washers or the housing gasket. Pray it's your valve
cover because if it's one of these other parts it's major surgery and not a DIY job less of course you know the tricks.

IF you already confirmed oil at the bottom of the vavle cover consider yourself a very lucky -- hopefully :wink:
I have, I could see it really well. Nice clean film of oil on the bottom of the gasket and the nearby fins.
1971 Pinzgauer 710M, all stock including 245-16 Maloya tires, taken off and stored for show
BFG MT KM2 265/75R16's on Black SAV replacement rims on now
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rmel
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Re: Engine Oil Leak on bottom of cylinder head nearest drive

Post by rmel »

Good! Your lucky IMHO. Might want to consider adjusting the valves while your into replacing the gasket(s).
I may take some flack for this, but the seats are not as hardened as the ones in your 2001 Porsche 911 so
depending upon this rigs history, there may be some valve seat recession so an adjust might be in order.
A clue: as the car talk guys would say "if your tappets are quite, time to adjust your tappets" :lol:
Puller: 71' 710K 2.7L EFI aka Mozo
Follower: Sankey MK 3, 3/4 Tonne
Rescue Pinz: 73' 712MK

Driver: Ron // KO0Q
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Jimm391730
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Re: Engine Oil Leak on bottom of cylinder head nearest drive

Post by Jimm391730 »

Hi Ron, I actually started my Pinz ownership with synthetic (for a few thousand miles, perhaps) but the oil consumption rate caused me to change my tune: if I'm effectively replacing all the oil in less than 2,000 miles, why use an expensive oil that should last for a lot longer? But during that time I never had a fouling issue, even with the stock shielded plugs and weak ignition system (compared to the civi conversion that I used later). I've just never gone back to synthetic for cost reasons.

So I can say that I've used synthetic in the Pinz with no ill effects, at least in my vehicle.
Jim M.
712W and 710M
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bbolander
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Re: Engine Oil Leak on bottom of cylinder head nearest drive

Post by bbolander »

rmel wrote:Good! Your lucky IMHO. Might want to consider adjusting the valves while your into replacing the gasket(s).
I may take some flack for this, but the seats are not as hardened as the ones in your 2001 Porsche 911 so
depending upon this rigs history, there may be some valve seat recession so an adjust might be in order.
A clue: as the car talk guys would say "if your tappets are quite, time to adjust your tappets" :lol:
That's a definite plan we had. Makes sense to do it when the covers are off.
1971 Pinzgauer 710M, all stock including 245-16 Maloya tires, taken off and stored for show
BFG MT KM2 265/75R16's on Black SAV replacement rims on now
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bbolander
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Re: Engine Oil Leak on bottom of cylinder head nearest drive

Post by bbolander »

Update. I cleaned off the #4 exhaust flange studs and then ran the engine and watched. The main oil leak is coming from the exhaust flange stud on the right in the picture. I can hear and see puffs of an exhaust gas leak near the stud on the left side.

I'll see if I can tighten the stud nuts to stop it.

I have new exhaust gaskets. Any tricks or problems to deal with in replacing them.

Why would so much oil be getting into the combustion chamber?

The picture is with the engine running after having cleaned the oil from the studs before starting the Pinz.
IMG_1272 running copy.jpg
IMG_1272 running copy.jpg (383.14 KiB) Viewed 6024 times
1971 Pinzgauer 710M, all stock including 245-16 Maloya tires, taken off and stored for show
BFG MT KM2 265/75R16's on Black SAV replacement rims on now
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rmel
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Re: Engine Oil Leak on bottom of cylinder head nearest drive

Post by rmel »

I would not recommend tightening the exhaust stud to stop a oil leak.
Oil should not be there in the first place. If it's coming from the combustion
chamber then it may be from a leaky intake valve guide, but you should see
blue smoke in the exhaust, and it would have to be pretty bad to also see it leaking.
Perhaps more likely from the exhaust valve guide, that would leak directly into the
exhaust port. This may be due to a plugged return oil pipe, you may want to remove
the valve cover and make sure the Oil return tube is not blocked causing excessive
amounts of oil at the top of the head -- potentially leaking more past the valve guides
than normal.

The other thing I can think of is a leak in one of the top push-rod tubes at the
head/cylinder or bottom return oil tube. But I don't see any indication of that in your
PIX as oil would be running down a bit closer to the block, further away from that
exhaust stud -- but then again oil is sneaky. Sii if there is any indication of oil on the
fins of cylinder #4.

Might try pulling the plugs on #3 and #4 and looking at what the plugs look like and
do a compression test while your at it.
Puller: 71' 710K 2.7L EFI aka Mozo
Follower: Sankey MK 3, 3/4 Tonne
Rescue Pinz: 73' 712MK

Driver: Ron // KO0Q
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rmel
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Re: Engine Oil Leak on bottom of cylinder head nearest drive

Post by rmel »

I cleaned up my previous posting with some corrections.
Puller: 71' 710K 2.7L EFI aka Mozo
Follower: Sankey MK 3, 3/4 Tonne
Rescue Pinz: 73' 712MK

Driver: Ron // KO0Q
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bbolander
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Re: Engine Oil Leak on bottom of cylinder head nearest drive

Post by bbolander »

I noticed when I've been doing all the looking at the leak, that I have the rubber valve cover gaskets! I believe I see a little seep at the bottom on #4 where it looks like there is a little chunk out of it. The other three look perfectly dry. I'll be replacing them with the cork and Permatex Aviation sealant on the cover when I remove any. I'm sure my previous Owner didn't put them in and he had it for 4 years and only drove 100 miles.
1971 Pinzgauer 710M, all stock including 245-16 Maloya tires, taken off and stored for show
BFG MT KM2 265/75R16's on Black SAV replacement rims on now
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rmel
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Re: Engine Oil Leak on bottom of cylinder head nearest drive

Post by rmel »

When you get those puppies off, check the oil return pipes, and the general degree of crud under the
cover -- it should be pretty darn clean, but if not might be a contributor in plugging things up.
Puller: 71' 710K 2.7L EFI aka Mozo
Follower: Sankey MK 3, 3/4 Tonne
Rescue Pinz: 73' 712MK

Driver: Ron // KO0Q
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audiocontr
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Re: Engine Oil Leak on bottom of cylinder head nearest drive

Post by audiocontr »

no sealant. Its not required. Mine are simply placed on and tightened up. They work just fine
1973 712m
1968 Haflinger
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Jimm391730
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Re: Engine Oil Leak on bottom of cylinder head nearest drive

Post by Jimm391730 »

no sealant. Its not required. Mine are simply placed on and tightened up. They work just fine
True, but a bit of sealant to adhere them to the valve covers makes any FUTURE removal and replacement much easier.
Jim M.
712W and 710M
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