pwb

Hi, after i did a seafoam and cleaned the engine the oil pressure is low? When the engien is cold the pressure is 3/4, after some time its 1/2 and on 1/4 when idle. after 1 hour its on 1/4 all the time, but it goes up to 1/2 when the rpm is on 2.500 and higher.
Its part syntetic oil, is this normal, should i go for 100% dino oil?
The picture is after a 15 min drive and then idle.
Its maybe 1000 km after last oil change and the oil still looks like new.

Creature85

Did you seafoam then change your oil or did you change your oil then seafoam? If it's the latter it could be some junk that the seafoam knocked loose is getting caught up in something.

pwb

seafoam in oil, then oil change, and then another oil change.

dave1123

JMHO, if the pressure goes up above idle and it's not knocking AT idle, I wouldn't be too concerned about it. Those 4-liter's are hard to break.

CrazyMacaw

Maybe the seafoam knocked some crap loose and it's partially clogged the oil pressure sending unit. Might try cleaning or replacing it.

pwb

If i should buy a new sensor, whats the best to buy?

kennzz05

youre probably fine 13 psi at idle is normal and acceptable
using this guide as a referance (below) it looks like you are about 21psi now looking at youre gauge i used 1.5 as the number i plugged in

http://www.convertunits.com/from/bar/to/psi

dave1123

Are you using the same oil that you were using before? I've been using the recommended 5W30 Synthetic in my 2000 WJ with 148K miles on her and thought maybe I'd try using 10W30 Syn because of the mileage. My pressure went up about 10 psi across the board at any different rpm or temp. That proved to me that she wasn't as worn as I thought she was. I'm going back to the 5W30 for the winter because cold startup pressure now is about 65 or 70 psi. My engine is the 4 liter I6.

It's possible your pump is worn and not delivering the VOLUME necessary to hold pressure around the bearing's leakage path, that is, the edges where crud builds up. You may also have cleaned out the valve lifters enough to speed leakdown on the off duty part of their cycles.

All this assumes the oil pressure sensor is working properly.

pwb

Its the same oil. I have new lifters and pushrod. The pressure is "normal high" when the oil is cold. After 30min the pressure go down when idle. But if it could be as low as 13PSI on idle i think its ok?

dave1123

As I mentioned in another post, I drove my company's old Chevy delivery pickup with 10 psi idle pressure for 2 years, waiting for it to blow up on the road. It never did.

If your engine's bearings don't rattle or knock at idle, you're good to go.

tiwvr1

Anyone take notice to his temp gauge reading?

bigbadon

Yes, and the two go hand-hand. High temp= thin oil...thin oil=lower oil pressure. Based on that his pressure is normal but his cooling system is not!

sycoglitch

I didn't care to chime in but his oil pressure, If lines transfer right to "American", at 20psi which is very much normal for idle. And half to 60 is normal when driving.

As for the temp, idk if that's considered 220-230, if the lines transfer the same to an "American" dashboard

pwb

The temperatur is another story. When i got the car the sensor (back on the engine) was bad. I replaced that and see that the temperatur is high. I have replaced this:

Radiator (i had a litle leak on the old)
Thermostate (tried 3 different)
Waterpump (but the old was fine)
Fan clutch
Temperatur sender (tried 3 different)
Temperatur sensor (in front)
Removed the head and checked if the water did flow where the sender was, and that was ok.
Testet the ohm on the sender and the gauge and everything is ok.
Tested the sender, sensor and thermostate in boiling water to see if its correct and it is.

When the gauge is at 110-115 it drops down to 105 when the thermostate open. If i drive without a thermostate it still show 110-115 but i take a litle longer to get there.

The temperatur on the water is 100% ok, the ohm on the front sensor is ok, the thermostate open ok, its not overheating at all.

Sometime when i make a hard left turn the gauge goes down to normal (90-95) for 3-4 sec, i have checked the wire and dont find anything.

andrewjohnson24

I would replace the oil pressure sensor I have the 5.2 in mine not the 4.0 but mine did the same until all the pressure was gone but I did the oil pressure test it was fin but I really wanted to know what my pressure was at all times, as soon as I replaced it went back to normal pressure. as far as your coolant temp goes my was opposite of yours mine would read extremely low until I replaced the coolant temp sensor and the coolant sending unit now I am running 210 when the engine is hot.