can someone please tell me what the oil pressure should be at idle in a 1990 twin turbo????

should be around 1bar for every 1000rpm, but you will probably find it goes to maybe 0.3bar when oil is nice and hot at idle

 

The stock gauge is pretty accurate but doesnt update itself very often (Most aftermarket update like 50+ times a second) so this is where the problem lies! As long as when your driving it reads a healthy amount (usually 3.5bar on motorway at 70 which will be around 2500rpm) and around 2bar in town driving is what i find if your cruising at 30mph

 

Hope this helps

If you do a search you will find the stock guage has a sender that fails every few years and reads low when hot yet high when cold. This is because it has a moving part that wears away the variable resistor surface in the part of its range that it is mostly in.

 

To convince yourself that it is not really at zero when idling just open the oil filler plug and look inside at the oil flooding over the cam lobes.

 

An engine with true zero oil pressure destroys itself very quickly.

Reads low when hot yet high when cold.

 

Well... thats because Oil is Thicker when cold thus more pressure to Pump it round and Thin when warm so Less pressure needed :mac1: Not due to a Faulty Sensor :)

 

But yes they are prone to failing as it may not have been changed so your Sensor is pushing 18+years old so well worth to change or get a new gauge and sender :)

Had the same low reading problem, just fitted a new OEM sender, problem solved, gauge reading noticeably higher all the time.

They are around £90 though! But worth changing for piece of mind.

Originally Posted by WillieO

Reads low when hot yet high when cold.

 

Well... thats because Oil is Thicker when cold thus more pressure to Pump it round and Thin when warm so Less pressure needed Not due to a Faulty Sensor

 

But yes they are prone to failing as it may not have been changed so your Sensor is pushing 18+years old so well worth to change or get a new gauge and sender

 

Re hot thin and cold thick - I kinda know that! I'm not quite that thick on engines.

 

And re age and wear on the sensor I know that too and mine has been changed a few years back and is going yet again.

 

The reason it reads properly and high when cold is because that part of the range the sensor operates on is unworn and the low end of the sensor range is worn so pressures less then 2 bar or 28psi can look like zero. That was the point I was making.

If you do a search you will find the stock guage has a sender that fails every few years and reads low when hot yet high when cold. This is because it has a moving part that wears away the variable resistor surface in the part of its range that it is mostly in.

 

To convince yourself that it is not really at zero when idling just open the oil filler plug and look inside at the oil flooding over the cam lobes.

 

An engine with true zero oil pressure destroys itself very quickly.

 

Exactly what he said - JeffTT explained it exactly like that when he replaced my old one last month! He dismantled one once to see how it worked;)

 

Well... thats because Oil is Thicker when cold thus more pressure to Pump it round and Thin when warm so Less pressure needed :mac1: Not due to a Faulty Sensor..................:)

 

True......

 

.......but when the engine is cold and the pressure is higher, the moving part inside the sender unit is not sitting on the variable resistor surface that is prone to wear! So when the engine is cold and the pressure is higher, the sender can read and report the pressure correctly. Once "normal" temp is reached and the pressure reaches the usual running level, the sender cannot read the pressure so it drops to zero-ish!!

 

The "normal" level is where the moving part spends most of its time; therefore that part wears quicker...

 

Richard:)