My '95 SSE (N/A) has 130K miles. I've had for 5 years now and since then I've been adding sytnthetic 10W40 Engine Oil. Recently, I've noticed when it'* in idle at a light that the Oil Pressure has been dropping below the safety range. Under normal driving the pressure is at 50-60PSI but at idle ti averages 20-30PSI. I know it'* not normal to drop below the safety margin. Is it the Oil Pump, Sender?

My 95 used to do that. I think it was the sender that was just screwy.

What you're experiencing is not uncommon. Sounds like the sender is fine if it'* actually moving up and down with the engine RPMs.

why are you using 10W-40 isnt that a little heavy????? Im just asking that for intrest, a heavier oil would actiually increase your oil pressure...... do you ever get lefter noise form usng a heavier oil on startup?

nicky

Oil pressure is pretty responsive to temperature. Check the temperature the next time the pressure is low. With idle speed low and temperature high, oil pressure usually will fall in all but the tightest engines. As your bearings wear and develop clearance, you may want to consider a higher viscosity oil like 15W-40. I like Shell Rotella T.

I had an old Mercedes Benz repair manual that said you were OK as long as the engine developed 7 pounds of pressure for each 1000 rpm. But, I must say, I would be very worried to see my pressure drop to 10 psi or less at idle!

I've actually been putting 10W-30 in the winter and 10W-40 in the summer. I'll have my mechanic look at the Sender and look into using 15W-40.

err.. the 30 and 40 is viscocity @ operating temp ( well past warm ups ).

The only thing I can think as stated as to why you would run 40'* is bearing and piston seal issues ( gettin a lot of blow by ).

15W-40 would only be thicker during start up compared to 10w-40 ( not including brands base stock and oil additive used. )

Well.. as far as I know any oil pressure between 20-100 psi I wouldn't worry about.

I'm running close to 80 PSI on throttle and during warm ups and around 60 PSI on Idle after 25 miles or so during idle.
I'm using Esso XD-3 0w-30.. I've tried different brands of oil and grade and they're relatively the same reading according to the gauge.. and as far as I know.. those gauges are never accurate for any car

I gotta read more carefully before I speak. Thanks for correcting me, Drifter.

no prob.. everyone has their typo days.. me included

But it takes a bigger and more mature man to admit to it..

My mechanic is going to replace the sender unit and if that doesn't work the oil pump. Where'* the Sender Unit? Is it difficult or expensive to replace? What about the oil pump? I've heard it could be internal, difficult to replace and expensive. Is this true?