Moonstone?

Hello everyone : ) I am in the prosses of rebuilding the engine of my 87 944S, and I'm finally getting to the point of breaking the engine in. When I first went to prime it I was getting little to no oil pressure. After quite a bit of trouble shooting, including replacing the oil pressure sending unit with OEM, replacing the oil pick up O-ring with an OEM one (I had a Victor Reinz rebuild kit), and removing the oil pressure relief valve and making sure it was in good condition. The oil pressure relief valve was stuck open when I first took it out but I was able to massage it till it moved freely. After doing all this I tried again and was able to get adequate oil pressure keeping it above 2 bar. So I moved forward, I did what a little bit of research told me was the first step to a break in. I turned the engine on and varied it's rpms between 2000-3000 for 20 minuets. during this time the oil pressure stayed at about 3 bar, even when I let it idle it stayed above 2.5 bar. It did have an oil leak from where the oil pump was so i added that to the list of things I needed to do.

I emptied the oil and took off the filter and removed the oil pump to look for any problems with it. I have a spare engine from a 8v so if needed I could replace the oil pump with the one off there, but it looked good to me. I replaced the oil pump this time making extra sure to clean every surface thoroughly. I did use the Permatex anaerobic gasket maker instead of Loctite 574 this time because I was out and had heard it was comparable, I also replaced the Victor Reinz crank seal with an OEM one. At this time an OEM seal set for the oil pressure relief valve came and I replace those too. After that the car then sat for probably a month with no oil in it because my sisters car blew a head gasket and that took all my free time for a bit.

When i came back to my 944 i did a few things non engine related to get the car road worthy for the next engine break in prosses. After filling it back up with oil (I use Castrol GTX classic 20w-50) and trying to prime it again I was getting oil pressure readings well below 2 bar. It was enough for it to turn off the oil light so I thought it was enough to start the engine and assumed the rest of the pressure was just lost due to the battery being a bit dead and not able to crank as fast. When I did start it the oil pressure did not go up in fact it slowly went down, and there was a bit of sound coming from what I assume are the lifters. (but no oil leak from the pump, little victories) Assuming is was the oil pressure relief valve again from sitting so long I took it out but it was fine. I also made sure that the crank shaft bolt was still torqued. I put the oil pressure relief valve back in, put in about another quart of oil so its definitely over filled now, and this time hardly even noticed any increase from where the needle is when the key is at ignition.It should be noted that I have not been using an alignment tool for the oil pressure relief valve, although from my understanding it is used more for installing the oil cooler and if it is not used and the oil cooler is not removed there should be little difference with removing and reinstalling the oil pressure relief valve.

I saw on Clark's garage that you might be able to narrow down where the lack of oil is if you take off the oil pressure relief valve and oil pressure sensor and try turning over the engine to see if any oil makes it to those components. When I remove the oil pressure sender a little bit of oil does come out, but when i crank the engine with the spark plugs and DME relay removed not a drip of oil comes out either of the holes. Clark's garage does say that he has not tried it himself but it seams like it should work. I put them back in and tried again, still nothing obviously.

I have very little clue on what could be wrong. I have seen places that the oil pick up tube likes to crack and lets air get through instead of oil, but I had thought mine looked fine when I was replacing the O-ring but I'm not sure. Does anyone know where they like to crack or have a picture of it for me to compare. That is the only lead I really have. This car I did buy non running from Copart. It had a spun bearing 2 so I fear whatever oiling problem I have is left over from that. So that is were I am at, I would love any insights into possible problems I am overlooking. (sorry for the wall of text)


TLDR: No oil pressure. Replaced oil pick up tube O-ring, oil pressure sensor, oil pressure relief valve seals, 20w-50 oil, re sealed oil pump, crankshaft bolt is torqued, no oil makes it to the OPS or OPRV when cranking with them removed, but every time I have removed them some oil does come out.

TurrFinn

If I were you I would reseal the girdle and oil pump with 574. 574 creates a hard seal. The Permatex you used could be softer than the 574 when cured allowing seepage of air into the oil gallerie on the girdle. Just a tip for applying 574 to a girdle, you can lay a bead down and just tap the bead with your fingers to spread it around. It will leave a very similar pattern to a paint roller. The o-ring for the oil pick up tube is white in the victor reinz kit, if you used the o-ring from the kit be sure you used the right one. Without the story of the engine I can't really say wheather or not the oil pump is fine but due to its unknown history it could be damaged. The oil pressure relief valve is one of the more annoying things to deal with. Your OPRV could also damage, weak spring, or a sticky valve. The oil pressure relief valve should thread in by hand. If it doesn't there is an alignment issue. I assembled my engine without the OPRV tool. First thing I recommend doing is tap and die the OPRV and its hole. Loosely install the oil cooler housing on the block, do not tighten the bolts down. Now insert the OPRV and tighten it all the way down by hand, you may need to giggle the oil cooler housing. Once the OPRV is finger tight, torque your oil cooler housing bolts. Then torque your OPRV. The sleve the OPRV slides into is pressed into the block, however it can become loose. If it is loose you will need to coat it in 574 and re-install it. When I do anything oiling related on my car I will remove the filter and crank it with someone watching for oil pressure. You won't flow much oil but you will flow some. I run 20W-50 in my car, You should see 5 bar cold. and 3-4 bar warm. Anything with RPM you should see 5 bar.

Best of luck with your 944 journey. Welcome to the forum.

harveyf

Welcome to Rennlist.
As this is your first post, be aware that many posts have been made about no or low oil pressure. You can get to them to read by using the Search function. Use the Advanced Search to limit yourself to the 924/944 category. Try various Keywords. It's a little kludgy with key words. I would start with "oil pressure".

There are many possabilities . @TurrFinn has given you a list for starters. Generally, we can't resolve a complicated problem in one post so keep actively involved, checking back to your thread, and providing answers to questions and updates.

You can get some background on the oiling system in an early 944 (should be similar to your engine) by reading my article linked below. Also, on my website, if you search on Rebuild, you should find my 5 part series on rebuilds. All of this is just to give you some ideas, something may ring a bell for you. But for instance, when you dealt with the spun bearing, was the crankshaft ground and if yes, did you use an oversize rod bearing.

It is my experience that air leaks on the suction path to the oil pump generally cause the pump to never prime and no oil is delivered. A stuck open OPRV returns oil to the suction side of the oil pump (not the sump) and could produce low oil pressure. The article linked shows the various OPRV types. Let us know which one you think you have. The updated design has a sleeve within a sleeve and in my opinion is not sensative to alignment. But you say you took yours back out and it was stuck open. Maybe provide a little more discussion of what that looked like.You should just be able to hold the valve in you hand and use a small round object to push the inner cylinder in at the insertion (small) end. The inner sleeve should push in and then release when you stop pushing. And please do not pull the valve axially because once you break the connection in the middle, it is a beast to get back together.

Good luck.

https://newhillgarage.com/2013/06/25...tem-explained/

walfreyydo

Try the most simple things first. Did you torque the crank pulley to 155ft lbs? If the crank pulley isn't torqued down it wont make a tight enough fit to drive the oil pump drive gear. Verify you have torqued the crank pulley and everything is reassembled correctly (oil pump drive gear, o ring, etc).