Oil Pressure And Bouncey Revs

[Paul Smith 0]

Hi

 

 

Since I have rebuilt the head on the 1989 1.6 GTI she pulls really well but is having a few little quirks and just after some help really.

 

firstly when she is cold the oil pressure is nice and high and she stays around here until i sit in traffic then the oil pressure drops to about half way and jumps back up nicely when accelerating just wondered if this is normal? Also also when she is warm and I am driving at say 70 mph and drop the clutch maybe to a round about or some thing it drops quickly to about a quarter then moves back to normal which is strange?

 

Secondly the revs bounce when driving if I pull up to a junction or round about they drop about 500 rpm lower than idle meaning I am having to idle her at about 1400 RPM just to tick over how can this be cured or is it normal?

 

Thirdly when she is hot and again puling up to something when i bring the clutch in the revs drop and pressure drops but they drop at the same rate and speed, coinsidental?

 

Any questions please ask

 

Thanks

 

Paul

[Anthony 1,003]

Given that the oil pump is driven from the crank, higher engine speed means the oil pump turns faster, and thus higher oil pressure (until the pressure is high enough that it reaches the limit of the oil pressure relief valve).

 

As for the revs going up and down, do a search on "hunting" and you'll find plenty of information on it - usually it's the result of poor setup, a faulty AFM, or excessive gunge built up in the throttle body etc.