About Rick O. Expertise Classic, aircooled (rear engine) 1949-1979 VW's, specializing in electrical problems, fuel injection, and Type 181 "The Thing".
NOTE: I have limited experience on water-cooled VWs (Rabbit, Golf, Jetta, etc...) but I am glad to help to the extent of my knowledge, due to the fact there are currently no other experts registered for these models.
Experience 15 years of aircooled VW ownership and maintenance.
Publications Wikipedia, VW Beetle
Education/Credentials Retired US military Electronics Tech/Master Training Specialist, Civilian Computer engineer.
Question QUESTION: Rick, hope you had good vacation, finally you are back I tryed to ask this question to other voluntier but they told me no experience on air cooled.
Any way do you remenber my problen in Ecuador with me Hans on no oil press on hot engine or after 180 o F. You said that the problem should be on the over pressure valve and the engine has two one big and other small. But my engine has only the big one near oil filter and is fine so the problem is not there. My engine crankase has only one overpress valve, it has a small hole in the place where the second should be machined or placed but the serial engine started with ED I beleaved is fuel injected where there is no second valve and no place for mechanical fuel pump. I got this engine 3/4 from Gex calf.
My car has this engine where I placed the original twin carb and a electrical fuel pump. So WHAT DO YOU THINK THE PROBLEM IS ?
I took the engine a part againg but I dont see any troble so far. I will sent the crankshaft to a diferent machine shop to chek it, hopping there is the problem on too loose oil gap on main bearings but really not sure.
Hans
ANSWER: Hello Hans,
Happy New Year! Hope your holidays were nice.
The ED is definitely a fuel injected case. Of course this is obvious since there is no mechanical fuel pump option. The second valve, which you do not have, is only to control oil pressure at high speeds.
I believe the problem is:
1) The pressure relief valve is stuck open, or the spring is too weak. This will cause the oil to never get to the oil cooler after warmup.
2) There is a blockage in the oil gallery leading to the oil cooler, or within the oil cooler itself. This will cause the same problem, no oil into the oil cooler.
- Rick
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QUESTION: Rick, happy new year to you as well.
I check the pressure relief valve, it if freely moving not jam and spring is ok. It is cutting oil press at 55 psi when engine is cold, but when oil passes 180 oF starts to decrese oil pressure to the point that when you acelerate over 3000 rpm oil reaches only to 40psi, does not get to 55 psi anymore so in other words the valve should be closed all the way but the oil pump cant reach to 55 psi anymore due to a loose of oil somewhere.oil pump is new and the old one was doing the same so the old oil pump should be good as well. I had the original spring on the oil relief valve before or just after the rebuilding of the engine ( after machining the crankshaft )i was cuuting the oil press at 80psi wich is way up forcing seals in the engine and gess what the same problem of the loose of oil press in hot engine that i have now. so the over press valve should be fine.
You second fact also checked. I made sure the oil lines in the entire block were free of blockage by blowing air with cleaning solvents ( gasoline ) with a pressure of 120 psi thru all part inside the block to make sure all pasages are clean so they are clean.
I also check the oil cooler gaskets thinking that when you thight nuts of oil cooler you could squease them cloosing the inside diameter of gaskets having poor pasage of oil. I place the original washers or spacers provided on gasket set ( german brand )to prevent these so oil should be passing with no problem to the oil cooler that is original VW. So WHERE ELSE COULD BE THE PROBLEM ?
I had another cuestion besides these oil problem. Can I place a camshaft ( 1800 cc engine) that belongs to an engine which has mechanical lifters ( not hydraulical )in a engine that has hydraulical set up. Are the camshaft diferent in the material thar are made or is the same part.?
Can I also instal a crankshaft from a 1800 cc that is heavier in weight and looks stronger than the original 2000cc, in a 2.0 cc engine.
I ask these cuestions because I have these parts used from my older engine where I know they were fine in that engine and I didnot have any trouble with oil pressure before. Do they will work fine on my 2.0 CC engine ? A heavier crankshaft will make the car move slower on hills and faster on highways. What do you think Rick?
Hans
Answer Hans,
Sorry for the delay, we are having snow storms and very cold temperatures in Montana.
Another possible reason for the oil pressure problem is a mismatched cam to oil pump. Your engine should have a four-rivet dished cam, with a 24mm or 26mm oil pump gear size.
The crankshaft swap should have no effect on the hydraulic valves, but the cam is different for hydraulic vs. solid lifters. However, I don't think it is a good solution to swap these parts around.
Another interesting point, if you had a dual relief case with two valves, the second valve (oil control valve) towards the front of the engine, is supposed to open at 42 PSI and 2500 RPM, which is about the same thing you are seeing. So are you sure you do not have a dual relief case? If you do, this pressure change would be normal.
