Hey guys, i recently did my oil change and noticed there was a small amount of milky oil on top of the pan (maybe a tennis ball size) and the rest of the oil was clean, the oil cap and dipstick were also clean. I noticed i had to fill up the radiator but i dont know if it was always missing coolant or if it happened recently. There was thick white smoke when i was giving it throttle. I did a compression test and got 175 psi in each cylinder. I had to unbolt the upper intake manifold to get to cylinder number 6. I tought maybe the headgasket as gone bad only recently, which would explain the little amount of milky oil and the high compression. So i decided to do a leak down test with a custom tool (https://www.youtube.com/watch?v=7UcOn8OEt0Y).
I did test on number 1, align last left notch of crank pulley with water pump arrow on top of the pulley and did the test (at cold). The air was rushing through the intake manifold port so i guess i have bad timing or bad valves but it's weird because the compression test was fine. I also noticed prestone was leaking from the rear passenger side hose of the upper intake manifold (i had to cut them to remove the plenum, i think its IACV and AAC). Now i'm waiting to do the other cylinders. I would like to know if i got the good way to find TDC and if it is normal to have good compression and a bad headgsket. I also think it might be the intake manifold to head gasket??
what you guys think
Last edited by gogogsr; 11-27-2012 at 12:45 PM.
Pressure was set on 50 psi on the left gauge, after plugging to the hose pressure drop to 40 and the right gauge reading was:
cyl : 31 =22%
cyl2: 36 =10%
cyl3: 35 =12%
cyl4: 35 =12%
cyl5: 35 =12%
cyl6: 32 =20%
I did notice a crackle sound on cylinder 4 and 6, kind of a metal gasket crushing. No bubbles in rad, no intake leak, no exhaust leak, just crankcase blow by, which considering the truck has 200,000 km on it seems fair. Remember that the compression was 170 across the board.
I'm thinking it could be the intake manifold lower gasket, what you guys think??
what do you think of this hypothesis: Intake manifold is leaking from its water port directly into the runner, which then drop into the combustion chamber, hence the white smoke. Some of it pass through the rings hence contamining the oil just a bit.
What you think???
no leak in radiator when doing leak down test, no lost of pressure when doing cooling system pressure test, truck runs good, compression is good. Is there another test i can do to try to find the culprit of burning coolant?
thanks guys, i'm this close to bringing it to the garage if i annot pin point the problem
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