QuestionQUESTION: I have a westfalia-bus 1978 twin carb. The engine was rebuild main bearings in engine are 0.25mm new oil pump, new oil cooler(standard vw)no oil leaks. I have VDO gages that shows oil temp, oil press, head temp. After 30min running engine the temp reaches 180 oF and starts loosing oil press and the temp rises more and more and pass 250 oF until the idiot light turs on. You have to stop the engine to cool down. I think that the hole problem is the lose of oil pressure that no longer flows to the cooler. The cuestion is where could be the reason? If I put a second oil cooler it will be no help if no oil go thru the second oil cooler kit. This problem didn´t have before engine rebulding except when oil had more than 3000 miles and climbing high hills in ecuador over 3000 meters over sea level where you over demand the engine, but when oil was recently changed no problems of overheating even if you over demand the engine. Now the problem is running the car with new oil in it, on higway or streets, after 30 min of driving.
What do you think the problem is located? The second oil cooler will fix the problem by keeping the temp. below 180 o F in a way to have more than 40 psi at 2500 rpm ? One thing that I forgot, If you let the engine running on idle speed for more than an hour the problem is the same.Why lose oil press.?
Hans
ANSWER: Hans,
I believe the problem is one or both oil pressure relief valves are not working correctly. There is a possibility the springs are incorrect; they are different sizes and different tensions. The front is longer and stronger, the rear is smaller and weaker. Another possibility is one of the valve plungers may be stuck open (not fully inserted) perhaps due to a warped port or other obstruction.
- Rick
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QUESTION: Rick,
On my engine there is only one relief or cut off valve and is located near oil filter. It has only one spring and a small piston that works freely. I change the spring because it was cutting of pressure at 80 psi, now it is doing its job at 55 psi I could find a softer spring to place it at 42 Psi which is the correct reliefed pressure acording to Chiltons repair manual. But this valve controls over pressure to prevent damage to the engine. My problem is poor pressure on hot engine. When was 80 psi the problem was the same no good press over 180 oF
I also replaced all hydraulic lifters when rebuinding engine and they are working good you can hear them for 2 seconds when you crank the engine in the morning and they silence when oil pressure build up.
I had to sent the crankshaft to the machine shop when rebuilding the engine because it had scratches do to poor maintenance, my brother had the car before and he wasn´t good on oil changes. It was fixed by taking .25mm of it. and I placed new .25mm main bearings ( mexican)
One cuestion that is on my mind. Do you think is possible that on the machine shop didn´t do a good job on the crankshaft and the gap for oil lubrication on main bearing is incorrect or too loose. Making it to loose oil press only when oil is more liquid at warm temperature. I ask this cuestion to another machine shop and they told me that when messurements are too loose there is no pressure at all, not even on cold engine. What do you think about that? By the way what is the correct gap for oil lube on bearings?
Do you think that a second oil kit will fix the problem by keeping or forcing the engine not to pass 180 o F in order to have good oil press in the engine? Or should I stay trying to find where is the oil press dropping.
I know I ask too many cuestions but the car is worhless because you can´t drive it for more than 15 miles and the engine is overheating. Head temperature stays at 250 oF which is the same temperature that before rebuilding the engine. Problem is located on poor oil press after 180 O F of oil temperature. You could see on VDO gauges how the pressure drops and the temp of oil increses rapidly until you end up on 5psi on idle at 260 o F and the idiot light turns on.... you have to stop engine before it blows up.
Hans
ANSWER: Hans,
Well, you obviously have a non-original setup. The engine code you have determines the specs. What is yours? Below are the possibilities (except Mexican):
Volkswagen Type 1
Code: Year: Engine:
4 1960 1200
5 1961 1200
6 1962 1200
7 1963 1200
8 1964 1200
9 1965 1200
FO 1966 1300
HO/TO 1967 1500
H5 1968-1969 1500
B6 1970 1600 (dual relief, single-port)
AE 1971-1972 1600 (dual-port)
AH 1973-1974 1600 (8mm head studs w/ case savers)
AJ 1975-1979 1600 (fuel-injected)
Volkswagen Type 2
Code: Year: Engine:
Numerals 1961-1963 1200 (see Type 1 listings)
O 1964 1500 (no cam bearings)
H 1965 1500
HO 1966-1967 1500 (no crossmember holes)
B5 1968-1969 1600 (single relief)
AE 1971 1600 (with crossmember holes)
CB 1972-1973 1700 (dual carb, manual trans)
CD 1973 1700 (dual carb, auto trans)
AW 1973-1974 1800 (dual carb)
AW 1975 1800 (fuel-injected)
ED 1975 2000
GD 1976-1979 2000 ('79 has Vanagon heads)
GE 1979 2000 (California only, Vanagon heads)
CV 1980-1983 2000 (Vanagon -- unique case and heads)
Volkswagen Type 3
Code: Year: Engine:
O 1963-1965 1500 (no cam bearings)
TO 1966-1967 1500
UO 1968-1969 1600 (fuel-injected)
UO 1970 1600 (dual-relief)
U5 1971-1973 1600 (7.7:1 compression)
X 1972 1600 (7.3:1 compression)
Volkswagen Type 4
Code: Year: Engine:
W 1971 1700
EA 1972-1974 1700
EB 1973 1700 (California only)
EC 1974 1700
Porsche 914
Code: Year: Engine:
W 1970-1971 1700 (8.2:1 compression, D-Jetronic)
EA 1972-1973 1700
EB 1973 1700 (7.3:1 compression)
EC 1974 1800 (CA-only, 7.3:1 comp, L-Jetronic)
AN 1800 (8.6:1 comp, D-Jetronic)
GA 1973-1974 2000 (7.6:1 comp, 3 intake studs)
GB 2000 (8.0:1 comp)
VO 1700 (Euro-only, magnesium)
1800 (Euro-only, magnesium)
2000 (Euro-only, magnesium)
Replacement Cases
(Never supplied in new cars -- only sold over the counter. All are
dual-relief with 10mm oil passages).
Code: Year: Engine:
F1 1300/1600
F2 1300/1600
DO 40-hp part if last digit is "X"
D1 Sometimes a 40-hp part
AB 1966-1979 1600
AD 1600
AK 1967-1974 1500/1600
AM 1600
AS Sometimes listed as Super Beetle orig. case
for '73-on.
- Rick
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QUESTION: Rick, you where right my engine has a second cut off valve on the righ just above the valve tubes. I never imagine that screw was it, it looked like one of the asembling screw for the crankcase. I will check this cut off valve tomorrow to see if its jamed or dirty. I will make sure it will move freely. I hope that will be the problem, if not I will write you againg.
By the way my original engine was 1800 twin carb 1975 model mechanical fuel pump, if I´m not mistaking was serial AP. Now I changed to 2000 Hydraulic lifters purchased on GEX calf.wich was rebuilded thereand I imported to Ecuador. Now I use and electrical fuel pump because I beleved this engine was fuel injected but anyway both engines has dual oil pressure cut off valve.
Thanks, I let you kow what happens
Hans
AnswerHans,
Check the relief valve spring sizes closely. I gave you the wrong description before: make sure the front valve (towards the transmission) has the short spring, specifically 26mm (1-1/16 inch). The rear spring is longer 39mm (1-9/16 inch). If these are mistakenly swapped in the wrong position, the rear valve will open too soon, which would bypass the oil cooler and therefore cause an over-heating condition.
Rick
