cold start valve &low oil pressure on 72 914 1.7

[bkbs22]

I know that a nonfunctional valve would cause poor idleing......could that in turn cause oil pressure to run low when the motor gets hot? Can someone disconnect their cold start valve at operating temperature and let me know what happens.

[jamcleod]

if you really mean the cold start valve, i don't think it can be connected to oil pressure in any way. the cold start is a fuel injection/gasoline supply item that only operates for a short (20ish seconds) when the engine is cold below a certain temp (around 50 F). don't regard these values as ones to be quoted. as the engine warms up, the oil will thin
(viscosity = f(temperature)) and oil pressure will drop. not sure exactly how the typeIV spring pistons work (enough to explain) but there are pressure relief pistons and temperature related pistons to re-route the oil flow. for example, if the oil is "cold", it bypasses the oil cooler.

DD will hopefully give a technically correct explanation.

the short is: no connection

PS: you don't mention what weight oil you are using. maybe you could use higher weight oil to increase pressure.

[Dave at Pelican Parts]

My CSV is permanently disconnected. It has no effect on the running of the car. As was mentioned, it only shoots some fuel into the intake manifold for a little time. What was not mentioned is that the only time it can do this is while the starter is cranking. (And that's only if the engine is "cold enough".)

If your idle RPM is very very low, like 500 RPM, that can easily turn the oil pressure light on when the oil gets warm and thins out.

If you use a light-weight motor oil (e.g., 5W30) in a 914, expect to see lower oil pressures than if you used a heavier oil (e.g., 20W50).

BKBS22, what kind of oil pressure are you seeing that you consider low? Under what circumstances?

--DD

[bkbs22]

Thanks Dave. Oil pressure is fine at start up, 60 to 70 psi. After idleing or driving for about 15 mins pressure drops to about 8 psi. I am using 20w50. Pressure does rise with rpm. 40 psi at 3000rpm.

[Dave at Pelican Parts]

That's not too bad, actually. You want 10 PSI per 1000 RPMs, and it sounds like you're getting that. Idle can be a little bit lower (note that spec idle RPM is 850 +- 50) and there is even a note in the owner's manual about the oil light flickering on when the engine is fully up to operating temps.

Unless this oil pressure is a recent change, I would be inclined to not worry about it.

--DD

[bkbs22]

Thanks again Dave. You have put my mind at ease,and I guess,I should also forget about the CSV not working. Time for me to just enjoy the car.