Hi, everybody.
Situation:
'97 Magnum 318 ... been losing oil lately ... no visible external leaks
... no really tell-tale signs from the exhaust pipe (after sitting overnight,
on startup, will blow out a bit of soot and lots of moisture vapour ...
running headers) ... running a 180F tstat ... no loss in coolant ... low
mileage
... weekend drag racing this season ... running 5W30 synthetic ... am
running rich
and switching back to stock tstat in this colder weather. I did a
compression test
and cyclinder 4 is off ... FSM says crank over 3 times and compression
pressure should
be 100 psi. Most of the loss comes after fairly brisk highway driving.
Results are (bracketed are plug condition):
1 152 (wet: oil) 2 150 (dry: aok)
3 150 (wet: oil) 4 130 (dry: aok)
5 150 (black) 6 145 (wet then dried out: gas)
7 145 (dry: aok) 8 150 (wet: oil)
I'm running the MP Magnum R/T cam which may account for the high numbers.
Also, ran compressed air through cylinder 4 and listened through a rubber
hose ... did not detect sound of leakage. Also, put oil in cyclinder 4 and
did a compression re-read. Removed rad during compression testing and
no bubbles in the rad coolant.
This leads me to conclude that rings are aok and maybe valve seals (or some
other valvetrain components) are the problem but I'm puzzled about cyclinder 4
compression reading. Any ideas at all? Thanks very much.
Bob. Southern Ontario, Canada.
'97 Dakota CC Sport, FR, 5.2L, 3.55 SG, auto.
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