Quote:
Originally Posted by rbtoj
the car start to miss fire on one, and sometimes two cylinders at idle and up to about 4000 RPM. If I then proceed to turn it off for about 30 minutes or so it start right up and runs fine again.
Also, there is an accumulation of oil inside the intake manifold in the form of a 2mm deep puddle. I have no explanation for where it is coming from, as there is no blowby (the breather on the valve cover actually has a little suction).
Other symptoms include:
-Slight oil fouling of the plugs, but no blue smoke or blowby;
-Manifold vacuum pressure at idle of only 14inHg (no EGR or other smog devices);
I just did a dry and wet compression test with the following results (valves were adjusted only 3 days ago):
Cyl / dry / wet / difference
1 - 120 / 130 / 10
2 - 118 / 135 / 17
3 - 120 / 132 / 12
4 - 122 / 135 / 13
5 - 122 / 135 / 13
6 - 122 / 135 / 13
If I have ring or cylinder issues, shouldn't the difference between wet and dry be a lot higher then just the 13 psi average that I've got? Or am I looking at an engine rebuild?
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Although cylinder wall condition and ring seal would appear to be good, the odds are substantial that at least two intake valve guides are loose in the head. They are the source of the oil in the manifold, and will cause an air leak and/or hold intake valves slightly out of position on their seats until everything cools a bit and they return to their intended place.