4.2 Oil pressure at hot idle
Discussion
The oil pressure on my 4.2 worries me - at cold idle it is about 40 on the guage, however once the engine has warmed up it drops to 20. After a long run this creeps down as low as 10-15! Above idle it picks up very quicly so by 1500 rpm it is back up above 40.It has behaved like this since I have had the car and I assumed this was normal untill I read of much higher idle pressures on here recently.
I have just done an oil change - Silkolene Pro R 10W50 a new filter and replaced both the pressure relief valve spring and plunger - none of which has made the slightest difference.
Am I right to worry or should I accept that its normal for my engine - it is running beautifully apart from the pressure concern.
I have just done an oil change - Silkolene Pro R 10W50 a new filter and replaced both the pressure relief valve spring and plunger - none of which has made the slightest difference.
Am I right to worry or should I accept that its normal for my engine - it is running beautifully apart from the pressure concern.
Thanks for all the feedback chaps!
Off idle the pressure is very healthy, hot or cold - over 60 + at 3k rpm.
I noticed the 10psi mention in the handook, which is why I havn't been too worried.
I changed the relief spring the prvious time I changed that the oil too and the pressure behaved exactly the same way, so unless the original and both replacements were all duds I dont think its the spring, which is why this time I replaced the valve plunger as well.
Point taken about the revs, mine does tend to idle a little low when hot which is probably contributing to things.
I am not sure what to do apart from have another go at cleaning out the valve body, next time I change the oil and replace the spring again. trackcar do you know if you can still get uprated springs by any chance?
Off idle the pressure is very healthy, hot or cold - over 60 + at 3k rpm.
I noticed the 10psi mention in the handook, which is why I havn't been too worried.
I changed the relief spring the prvious time I changed that the oil too and the pressure behaved exactly the same way, so unless the original and both replacements were all duds I dont think its the spring, which is why this time I replaced the valve plunger as well.
Point taken about the revs, mine does tend to idle a little low when hot which is probably contributing to things.
I am not sure what to do apart from have another go at cleaning out the valve body, next time I change the oil and replace the spring again. trackcar do you know if you can still get uprated springs by any chance?
I dont think there was any uprated springs as such for pressure, there was an alternative spring that didn't snap as often but as far as I recall it wasnt intended to up the pressure over an otherwise std old style spring, just stop the drop off happening as the spring took a set or snapped.
If youre still struggling for pressure youve got to assume either your pump or bottom end are worn.
If youre still struggling for pressure youve got to assume either your pump or bottom end are worn.
BLUETHUNDER said:
Tanguero said:
Thanks for the info trackcar, I guess the idle pressure will just gradualy deteriorate until I have to have a rebuild. Like I said - pressure is fine at anything above idle so I think I can live with it untill that time comes.
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