SR20DET Oil Pump Priming

Problems, ideas and comments specific to engine swaps.
Post Reply
User avatar
PoorMtnKid
Supporter
Posts: 1203
Joined: 28 Aug 2010 14:43
Location: Las Vegas NV

SR20DET Oil Pump Priming

Post by PoorMtnKid » 07 Oct 2018 19:52

Back in April I took my engine to a local machine shop for a full rebuild. Just this weekend I fired the engine for the first time but I'm not getting any oil pressure throughout the system. I have tried to search the typical SR forums about priming the pump and most lead to just removing spark/fuel and cranking for so many seconds so many times and boom your good to go...... Well that is not happening. I have an oil cooler so I used my air compressor to blow air through both side of the feed and return lines on it. When I blow through one hose I can hear it blowing bubbles in the pan. I then added oil to the lines and blew through the other hose and oil came out of both the turbo feed line and also above the cams in the head. So I know the passages are clear, yet the pump does not want to pull oil through.

Does anyone out there have experience with the SR oil pump and how to jump start them? I have read to pump oil through the fitting the oil filter mates to, I will try that soon but I'm really frustrated with this thing and would like to cut to the chase if possible.
looking for pass. side arm rest

datzenmike
Supporter
Posts: 5353
Joined: 24 May 2006 12:40
Location: Van. Isle.

Re: SR20DET Oil Pump Priming

Post by datzenmike » 07 Oct 2018 20:59

Assuming the oil pump works, push oil back through the pump instead of air. That will fill it and the pick up tube.
"Nissan 'shit the bed' when they made these, plain and simple." McShagger510 on flattop SUs

User avatar
Byron510
Moderator
Posts: 12064
Joined: 01 Jul 2003 23:06
Location: Maple Ridge, BC

Re: SR20DET Oil Pump Priming

Post by Byron510 » 07 Oct 2018 21:02

PoorMtnKid wrote:
07 Oct 2018 19:52
When I blow through one hose I can hear it blowing bubbles in the pan.
Just checking, are you pulling oil from the pan - cooler - pump - Filter => engine?

Or is the oil going from the pan - pump - cooler - filter => engine?

Just clarifying.

Byron
Love people and use things,
because the opposite never works.

User avatar
PoorMtnKid
Supporter
Posts: 1203
Joined: 28 Aug 2010 14:43
Location: Las Vegas NV

Re: SR20DET Oil Pump Priming

Post by PoorMtnKid » 08 Oct 2018 07:49

Byron510 wrote:
07 Oct 2018 21:02
PoorMtnKid wrote:
07 Oct 2018 19:52
When I blow through one hose I can hear it blowing bubbles in the pan.
Just checking, are you pulling oil from the pan - cooler - pump - Filter => engine?

Or is the oil going from the pan - pump - cooler - filter => engine?

Just clarifying.

Byron
I was trying to research that also on the SR20's but couldn't find anything yesterday. This is how I think it goes, someone correct me if I'm wrong.

Pan-pump-filter-cooler- engine.......

I have read on other forums of people using the turbo feed line hole on the block to fill oil back until it spews out. So I may try that later tonight.
looking for pass. side arm rest

User avatar
icehouse
Posts: 3290
Joined: 17 Jul 2005 17:06
Location: Everett Wa

Re: SR20DET Oil Pump Priming

Post by icehouse » 08 Oct 2018 08:06

I built a tank that holds 1 gallon of oil. The tank has a line off the bottom I screw into the oil pressure sending unit hole in the block. The tank has an air supply line at the top with a valve, I hook my air compressor up to it and pressurize the tank. Some engines you can see oil start to pool up in the head through the oil cap hole, some you have to take the valve cover off. I've used it few times with great success.

A good buddy of mine who is the best shade tree mechanic ever! He always has a trick to do the job with no extra tools, told me he fills the engine with way to much oil, like a gallon extra, enough so he knows the level is above the oil pump, that way it self primes do to the natural level of the oil. Then he cranks it till he gets oil pressure, drains the excess oil and fires it up. I've only attempted this method on engines I don't care about! haha.

My two ideas.
"People don't like it when shit doesn't match their rule of thumb." Sam

User avatar
PoorMtnKid
Supporter
Posts: 1203
Joined: 28 Aug 2010 14:43
Location: Las Vegas NV

Re: SR20DET Oil Pump Priming

Post by PoorMtnKid » 08 Oct 2018 11:23

icehouse wrote:
08 Oct 2018 08:06
I built a tank that holds 1 gallon of oil. The tank has a line off the bottom I screw into the oil pressure sending unit hole in the block. The tank has an air supply line at the top with a valve, I hook my air compressor up to it and pressurize the tank. Some engines you can see oil start to pool up in the head through the oil cap hole, some you have to take the valve cover off. I've used it few times with great success.

A good buddy of mine who is the best shade tree mechanic ever! He always has a trick to do the job with no extra tools, told me he fills the engine with way to much oil, like a gallon extra, enough so he knows the level is above the oil pump, that way it self primes do to the natural level of the oil. Then he cranks it till he gets oil pressure, drains the excess oil and fires it up. I've only attempted this method on engines I don't care about! haha.

My two ideas.
I did read of the overfill method as well, just seems odd to have to go through that. I was thinking of making some type of tank like you mentioned that I can hook up to my oil cooler line or turbo feed line and do what your saying. Was the flow described the correct way the oil flows on an SR? What could the machine shop have done incorrectly to not have the oil flow? The only thing I read is there is an O Ring that if missing the pump just sucks air and will not create a vacuum to pull the oil from the pan.......
looking for pass. side arm rest

User avatar
spriso
Posts: 233
Joined: 28 Feb 2007 07:39
Location: Oregon
Contact:

Re: SR20DET Oil Pump Priming

Post by spriso » 09 Oct 2018 07:50

Oil pump priming on a SR20DE/T is very important and we developed this method years ago when we start an engine that has been sitting a long time or that has had the oil pump replaced that has worked well for us.

What we do is use a simple in-line pump that is driven with a cordless drill-- we then replace the stock SR20 oil filter housing with an aftermarket unit that looks like this (you can buy Chinese knock offs for a very reasonable price on eBay):

Image

This block is mounted with 4 socket head cap screws and is easily removed and replaced.

Hook up some vinyl tubing to the inlet and outlet of the housing, stick it into a quart of clean oil and spin the pump until you see oil dripping out of the camshaft oilers.

Here is a quick video of the process that shows how we do it:

https://www.youtube.com/watch?v=KBRERtNu500

Hope that helps,

Michael
Michael Spreadbury
Spriso Motorsports
www.spriso.com

User avatar
PoorMtnKid
Supporter
Posts: 1203
Joined: 28 Aug 2010 14:43
Location: Las Vegas NV

Re: SR20DET Oil Pump Priming

Post by PoorMtnKid » 09 Oct 2018 11:42

Hey Michael

Thanks for the suggestion, I was able to come up with a plan. So I have a oil cooler adapter block similar to this already that runs to my oil cooler, I was able to source an AN fitting that can connect to the end of the IN line and I was able to pick up some tube and a drill pump. I'm going to try your method later today.

One thing I don't understand though is pumping through the IN port pushes the oil into the engine journals, how does filling this help pre oil filter down the pump and pick up tube? Or are you saying I need to pump oil into the IN and OUT ports to just try and fill the entire system? Just trying to understand if filling this helps create a vacuum or something.
looking for pass. side arm rest

User avatar
spriso
Posts: 233
Joined: 28 Feb 2007 07:39
Location: Oregon
Contact:

Re: SR20DET Oil Pump Priming

Post by spriso » 09 Oct 2018 20:40

We have used this technique on all the SR starts that we do, and it has worked perfectly... let me know how it works out for you...

Michael
Michael Spreadbury
Spriso Motorsports
www.spriso.com

User avatar
PoorMtnKid
Supporter
Posts: 1203
Joined: 28 Aug 2010 14:43
Location: Las Vegas NV

Re: SR20DET Oil Pump Priming

Post by PoorMtnKid » 10 Oct 2018 18:06

No luck =(

I tried this method and was able to get oil coming out of the camshaft oilers, turned the car over and still get no pressure. During the replacement of the oil pump what could go wrong, missing, incorrect , etc. to cause this problem?

On thing I read is there is an O-ring that if missing the pump would just suck air and not allow it to pump the oil....... Pretty upset right now with this entire process as the damn machine shop said it would take 6 weeks and it took 4 months. And now that I'm getting it in and buttoned up I'm running into this problem.
looking for pass. side arm rest

User avatar
PoorMtnKid
Supporter
Posts: 1203
Joined: 28 Aug 2010 14:43
Location: Las Vegas NV

Re: SR20DET Oil Pump Priming

Post by PoorMtnKid » 15 Oct 2018 16:15

Latest update. I took off the pan to inspect the pick up tube for cracks, it looked good but the o ring was obvious it was never replaced. I have ordered the later model sr pick up while I'm in here. The plan at this point is to put the later style in, bolt back up and try again using the drill pump set up. If results are negative my next direction would be to inspect the front cover/pump area.
looking for pass. side arm rest

Post Reply