Author Topic: no oil pressure help! (Read 5327 times)

accota · « **on:** July 22, 2012, 12:58:50 PM »

I was driving the other day, maybe a bit heavy on the throttle but nothing extreme. Suddenly oil light went on and went away again.
Since that day the oil light refuses to go out. So I took of my lower pan, removed the timing case to check for blockage. There was nothing wrong to be found, blown through the oil passages. Yesterday I put everything back together with fresh gaskets. And again today the same problem, no oil pressure, replaced,oil pressure sender, which wasnt even oiled.
I cranked for 30 seconds and the oil level was the same. The hydrolic lifters also make a heck of a diesel noise. So my conclusion is the oil pump doesnt suck oil.
Does somebody know what can be the cause of this? I'm getting tired of taking my engine apart and putting it back together. please help!!

bmwman91 · « **Reply #1 on:** July 22, 2012, 03:50:14 PM »

What weight of oil are you using?

Did you check the pressure relief valve when you had the oil pan / timing case off? The spring may have broken or the plunger may have seized open, basically causing all of the oil to go through the pump and right back into the pan. The pressure relief parts were updated over the years, and you might have the old seizure-prone parts in there.

Did you put a new upper oil pan gasket on? Were all of the bolts around the pickup passage (in the upper pan) good / not stripped?

accota · « **Reply #2 on:** July 22, 2012, 05:35:00 PM »

thanks for the expertise.

The oil i'm using is castrol magnatec 10w40.

The timing case is off an e36m42 with the upated guide rail. It was updated since the old one had the profile gasket problem. So maybe the valve is updated already?

I have pushed the pressure release valve and it pushed itself back out, is it worth updating them still? From what u describe the fault is here.

The upper and lower pan gaskets are new, and the bolts torque smoothly to 11Nm. Also put blue loctide on them.

bmwman91 · « **Reply #3 on:** July 22, 2012, 08:18:08 PM »

Is the relief plunger metal or plastic? If plastic, it is the new one.

You should be able to push the plunger down and it should pop back up, but it should be very stiff.

DesktopDave · « **Reply #4 on:** July 23, 2012, 07:12:11 AM »

I'd drop the lower pan again. Check that the chain is still mounted on the pump, drive sprocket is OK, verify that the lower oil pan gasket is seated and intact while I was down there.

accota · « **Reply #5 on:** July 23, 2012, 08:18:13 AM »

the pump is mounted in the timing case, with the crank going through it.

I didnt take out the release valve, but the spring was hard indeed.
I'm going to order a new release valve and drop the upper pan again. I have no idea what else it can be. Is the updated release valve the one from the e36m42 compact?

What is the oil traject?

pickup* -> pump -> main bearings -> filter?
*->pressure release valve

bmwman91 · « **Reply #6 on:** July 23, 2012, 10:03:28 AM »

oil pan => pickup + pressure relief bypass => filter + pressure sensor => rest of motor => oil pan

If the spring is still stiff, then it is probably OK. Yes, I do believe that the E36 parts are the ones that you want. You have had the timing case off, correct? Have you remove the pump cover and inspected the gears?

accota · « **Reply #7 on:** July 23, 2012, 11:01:08 AM »

Yes I removed the cover. There was a small scratch in the surface of the timing case but rly small. Can this be the cause, it rly was a minor scratch? The gears turned smooth in each other.

Could there be another reason why the pump doesnt suck oil, other then a faulty pressure release valve or leaking gasket (which i doubt)

bmwman91 · « **Reply #8 on:** July 23, 2012, 03:33:48 PM »

Did you have the whole timing case removed from the motor? If so, was this scratch in the circular oil pump cover on the back? Or was this scratch in the main timing case casting, in the front where the pump gears are? Maybe it is actually a crack in the timing case around the pump gears. It could happen if a small piece of debris was sucked into the pump (which did happen to me once, although the entire oil pump housing exploded very obviously).

DesktopDave · « **Reply #9 on:** July 23, 2012, 04:16:40 PM »

Quote from: accota;113892

the pump is mounted in the timing case, with the crank going through it.

I didnt take out the release valve, but the spring was hard indeed.
I'm going to order a new release valve and drop the upper pan again. I have no idea what else it can be. Is the updated release valve the one from the e36m42 compact?

What is the oil traject?

pickup* -> pump -> main bearings -> filter?
*->pressure release valve

Oh yeah, that's right. I was stuck on M20/M30 pumps there. Never been in the timing case myself, so I'll leave this to the more experienced members.

accota · « **Reply #10 on:** July 27, 2012, 07:42:26 AM »

Quote from: bmwman91;113899

Did you have the whole timing case removed from the motor? If so, was this scratch in the circular oil pump cover on the back? Or was this scratch in the main timing case casting, in the front where the pump gears are? Maybe it is actually a crack in the timing case around the pump gears. It could happen if a small piece of debris was sucked into the pump (which did happen to me once, although the entire oil pump housing exploded very obviously).

Well, I assembled the engine a couple weeks ago but after working fine for a day, it stopped working the next one.

So I took the timing case off. I found some scratches in the circular part of the pump, cover and timing case itself. This didnt look that bad as it sounds. But I had a better pump lying around so that's in there now. I'm pretty sure the case isn't cracked. I cleaned it again and found no traces of cracking.

Just went to pick up new release valve and gaskets from stealer so hopefully it'll work tonight. I'm gonna put a little bit of grease in the pickup line so the pump can suck better.

I saw that oil pump massacre, trying to avoid that

. It's already the second timing case, don't fancy a third one.

Would it help to install a new oil filter? it has run about 100km or so.

Thanks for the support, this rly is a great forum.

accota · « **Reply #11 on:** July 27, 2012, 10:56:37 AM »

Great news! I found the pressure release valve is stuck, so problem solved I guess

Now only have to find a way to get it out, suggestions?

bmwman91 · « **Reply #12 on:** July 27, 2012, 11:28:49 AM »

Hey, congrats! I assume that it is stuck open/down, right (stuck depressed toward the spacer bushing in the pic)?
http://www.m42club.com/forums/showthread.php?t=14015

As far as getting it out, I would start with the cir-clip, spacer bushing & spring. For the plunger, I would spray a bunch of liquid wrench or other penetrating oil in and around it and see about drilling/tapping some threads into the accessible end of it. Then thread a long bolt into it and try to twist/pull it out. I assume that the one in there is made of metal...which is probably why they later switched to plastic since it is less likely to get stuck!

If you can, take a couple of pictures. I am curious to see how this thing fails as I have only ever heard about it but never seen it.

accota · « **Reply #13 on:** July 27, 2012, 02:35:14 PM »

I think it was stuck somewhere in the middle. When hammering I felt it going deeper. To get it out, I gently hamered a steel bar for concrete in it and pulled it out all together. Wasn't great fan of drilling with metal flakes flying around in the engine, it was the backup solution.

I'll remember to take a picture of the faulty valve, since I have no working camera atm. There was a mark where it got stuck.
It was indeed the metal plunger and sleeve, which is remarkable because it's a timing case from an 318ti.

The replacement plunger and sleeve were from plastic and are now in. Hope that's the last of the oil debacle. still need to put lower pan on.

grts

accota · « **Reply #14 on:** July 28, 2012, 08:00:12 AM »

So it was the stuck pressure release valve, she purrs again like a kitten. this can be helpfull for others.