No oil pressure

[Frittjoff20]

Hey guys!

Ive just rebuilt mig engine again after a mainbearing failure a few years ago.
I have mounted a new oil pump, the block has been boored and new pistons and rings, bearings etc have been installed.
I Have also mounted new hydraulik lifters.

My problem is that it doesnt seem to have any oilpressure? If i unplugg the hose to my turbo and fire it up i have oil coming out. If i unplug my oilcooler (15rows) there is also oil.

I have removed the sump and checked the oilpickup and resealed everything.

I have mounted an mechanical oilgauge on the block below the intake but there comes no oil with the engine running???

[LSG]

Have you cranked the motor with the oil filter off . See if your getting oil there could just be a air lock.
I guess all the oil ways are clear and you know what caused your main bearing troubles last time. Also I don't think running it's up now you know you have a issue. Just remove your spark plugs and crank the motor till you can get some oil coming out of the oil lines ect

[Frittjoff20]

No i havent tried removing the oil filter, i will try!

Yes im running the engine without sparkplugs until i solve the problem.

[Frittjoff20]

Ive removed the oilfilter and refilled it with oil i have also switched the hoses for the oilcooler and primed the pump? With oil in both the oil line to the turbo and the hose to my oilpressure meter. If i crank the engine i get a little oil in the oil line to the turbo.

[Frittjoff20]

Now i have changed the oilfilter with a new one prefilled.
i have removed the check valve and i have unsrewed the temp sensor on the oilpump and there came out alot of oil.
any ideas? Im out of ideas..

[Tractor Dave]

Is the plunger and spring above the oil temp sensor correctly fitted?

[Frittjoff20]

Yes

[newsh]

Did you fit ARP main bearing studs?

If one stud is not shortened it's possible to damage the pressure valve behind the sensor.

https://www.s2forum.com/forum/techni...main-cap-studs

[Frittjoff20]

Yes i have arp studs. And i have removed the pressure valve, it was fine.
it looks like i have to remove the sump again and remove the oilpump

[newsh]

Yes i have arp studs. And i have removed the pressure valve, it was fine.
it looks like i have to remove the sump again and remove the oilpump

Ok, yes it does.

[steve briance]

I have a memory of reading somewhere about the oil pump drive that is on the end of the crank and how it can come loose. If its loose it won't turn the pump very well, i guess it may be driving enough to circulate oil through open pipes but not able to push oil through the bearings?

It is unusual and apparently more of an issue on high power engines but, if you are going as far as looking at the pump again, check it out.

[Tom_]

As you said Steve, this is more like "high hp", but could be worth checking. I pre-lube the engine from the oil temp sensor. If you do this, you have to have an oi pressure and get rid of any of air bubbles trapped in the system