first rebuilt engine start up (how long for oil presure)

[supraguru05]

im starting up my 7mgte that i just rebuilt. it has a remote filter mount running into a oil thermostat running into a cooler. i filled the filters and cooler before instaling the lines. my problem is i am not getting any oil to the oil pressure sender. the engine is full of oil and i removed the return line off the thermostat and had oil spary at me. im wondering how many 20 sec cranks it generaly takes to get oil out of the oil senders hole. im kinda worried that cranking the car without pressure like this might mess somthing up. but since i got oil to pump thru the thermostat that means the i must have put the pump in right so im not sure what all i can check

 

[Junior]

cranking without oil pressure isn't a big deal, if it fire up you'd be in trouble.

are you sure the oil pressure sender is good? sure that it's a US spec sender and not a J-spec one?

 

[supraguru05]

yes sender is good. i literaly removed the sender and put a rag to see if oil comes thru and it did not so the main oil galley must not be full or is leaking out somewhere inside the block (not sure if that can happen). update i just blew the hole where the pressure senders goes clean with air and heard it in my filters so the lines are clear. i have less that 10ft of oil line if there is air in the oil lines can that restric oil

 

[Junior]

sounds like you've got a blockage somewhere. air shouldn't be an issue, your oil pressure on a full crank should be atleast 80psi, so you'd have to have like 5 vertical air pocket blockages to do that, unless you've got a gigantic lazy loop coil in there that shouldn't be it.

dunno what to tell you man, be glad you did this check, if you hadda fired it up with no pressure that woulda been alot of money down the tube.

 

[mkIIIman089]

I would have hit the oil pump drive with a drill long ago...

 

[bigaaron]

Make sure you don't have the hoses plumbed backward to the oil thermostat. If it's a Greddy style thermostat, when plumbed backward you will have no oil pressure to the engine.

 

[supraguru05]

ok we just back filled the oil sender hole with oil and still got no pressure building. right now we are removing the filter adapter to screw a filter right onto the side of the block to see if we get oil pressure then. i cant take a drill to the oil pump gear because the timing belt is on the radiator is in and the harmonic balancer bolt is tight. the thermostat is plumbed the right direction thats why oil came out of the hose that goes back to the block. if there is a blockage in the block what can i do


its like the resevior of what would be pressureized oil is leaking out faster than it can be filled so we cant ever get oil out of the sender hole

 

[supraguru05]

does oil come out of the filter stud or go into it (hte filter adapter might be labeled backwards)

 

[Justin]

Make sure you don't have the hoses plumbed backward to the oil thermostat. If it's a Greddy style thermostat, when plumbed backward you will have no oil pressure to the engine.

x2

::hang::

 

[supraguru05]

its a perma cool i htink its plumbed correctly but i also think we just screwed the filter onto the stud (removing all the cooler remote filters and everything else and i think we just got pressure ill confirm shortly we are hooking the pressure sender back up but again does oil go into the filter stud or out of the filter stud

 

[mkIIIman089]

My brain early exploded trying to decode that.

 

[supraguru05]

updated understandable summary

the engine is a 7mge engine with all the 7mgte stuff bolted on it. the only thing different is that where the pressure sender went there is a T fitting so i can run the turbo feed from there and put the pressure sender in there so on that one port i have the turbo feed and oil pressure sender. also this motor has a earls remote filter adapter on the engine. this then went to a permacool dual filter mount then to a permacool thermostat then to a cooler. we were unable to build oil pressure on cranking so we removed the oil pressure sender and no oil came out. next we unhooked the filter adapter and just put a filter on the side of the block (like it is a na engine) we still did not get any pressure what i am thinking now is that because of the t fitting we can not read pressure because the oil is just going through into the turbo

 

[Facime]

I dont believe thats right. If you have oil going to the turbo then you would have that same pressure going to the sender. Pressure would read system wide no matter where you put the sender unless you actually have no pressure. Someone else can feel free to correct me, but thats what my logic tels me.

REgardless of that there is one thing youo need to double check. Make sure that the direction of flow is correct going to the oil filter. If its backwards the anti-backflow valve (or whatever its caled) will stop the oil at that point and you will have no pressure on the back side of that and MASSIVE oil pressure on the front side of it.

Also, just for simplicity sake there is a 1/8" NPT hole right behind the oil return fitting on the Turbo block. I dont know for sure if its there on the NA block but you can look. If that hole is there you can use it to read pressure and let the stock location feed the turbo alone. I would do that anyway just in case your fittings for the sender block or restrict oil flow to the turbo in anyway.

 

[bigaaron]

edit: he beat me to it ^^^^


The threaded hole for the filter housing on the block is the oil inlet. The little hole under the threaded hole comes from the pump. Some brands of oil filters have an anti-drainback valve in them, so getting the hoses plumbed correctly is VERY important. The stock pressure sensor is at the end of that main oil galley in the block, if you have no pressure there, the bearings have no oil pressure either. You should have instructions that came with all your external filter/cooler stuff, I would recommend assuming something is plumbed wrong and check it all again.

 

[supraguru05]

thanks for the help let me reiterate the current state of the motor is with none of the cooling stuff on its now filter right on the block. we still read no oil pressure i belive because of the t fiting. remember moving fluid has very low pressure. so what we did was block one side of the t we still had no oil pressure (according to factory gage) we hooked up a mechanical guage and read 15-20psi i now belive that my factory guage in dash is broke. we are using a mechanical external guage and reading cranking pressures from 10-20 psi. what we are doing now is drilling the plate that is right below the filter threading it and using it for a after market mechanical oil presure guage. this will allow us to use the old sender port just for the turbo feed


on a positive note driftmotions slave cylinder master clyinder and line went in smoothly and are a great product

 

[bigaaron]

But that spot only tells you the pressure coming right out of the pump, not what pressure the engine internals are getting. If you had a plugged filter or something wrong with the external filter plumbing, you might not notice.

 

[supraguru05]

theres no other way using a t fitting in the factory sender hole will not allow you to read pressure according to what we are seeing we are going to try again the problem is the turbo feed lets all the pressure out so we have fast moving oil going by the factory sensor and it reads low pressure because its not reading stationary fluid pressure

 

[supraguru05]

ok heres whats going on


we have a t fitting in the factory hole for the oil pressure sender. one of the ports goes for the turbo feed the other port is where we screwed the pressure sender into.

using this setup we read 0 oil pressure cranking

next we took the turbo line off and blocked that port this would make the setup like it came from the factory with just the pressure guage in the hole. doing this we read 10-20

this is why i cannot use a t fitting for the turbo and read the oil pressure. now the question becomes where is the best place to read oil pressure other than the factory port location or is there another better place to get the turbo feed from. the port beneath the filter stud is a option and i belive we are going to use that for the pressure sender now

 

[Doward]

Just off hand, with the pressure gauge hooked up on the T, does oil physically come out of the oil feed line? (when it is reading 0 psi)

 

[supraguru05]

Just off hand, with the pressure gauge hooked up on the T, does oil physically come out of the oil feed line? (when it is reading 0 psi)


yes oil shot out of the fitting for the turbo feed and we read 0 on our oil pressure guage (the mechanical one we hooked up)


irght now we drilled the flange below the filter stud and hooked a guage up to it to read the pump pressure. the pump pressures are normal and when we started the car we were able to see the relif valve spring open and dump around 75-80 psi.

this whole t not working for pressure thing is still confusing me tho

is there somewhere else i can hook into to see hte oil galley pressure