Pelican Parts
Parts Catalog Accessories Catalog How To Articles Tech Forums
Call Pelican Parts at 888-280-7799
Shopping Cart Cart | Project List | Order Status | Help



Go Back   Pelican Parts Forums > BMW Forums > BMW Technical Forums > 101 Projects Discussion Forum: BMW 3-Series


Reply
 
LinkBack Thread Tools Rating: Thread Rating: 1 votes, 5.00 average.
Author
Thread Post New Thread    Reply
Registered
 
Join Date: Mar 2007
Location: Florida
Posts: 86
No oil pressure

So my M3 (e36) ran great all day Sunday at Sebring, and continued to run on the street until I put it up on Jack stands to check brakes, and change the oil. I started the car and let it warm up, there was no problem with oil pressure at this point. I dropped the oil, and changed the filter, refilled with 7 qts and restarted the engine. The oil pressure light came on at first as usual, but then didn't turn off. After about 10 seconds I shut down the engine and began scratching my head. I double checked the level of the oil, the dipstick shows full. What could I have done during a simple oil change that would cause the car to loose oil pressure.

I removed the oil filter canister lid, and absolutely no oil in the can. The new filter was still dry. It appears the oil pump is not pushing oil up to the canister. I can't believe the incredible coincidence of the oil pump failing just as I change the oil, but it appears that is what happened.

Does anyone have any other explanation? Again there is no oil coming into the filter canister.

Old 11-13-2008, 02:22 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #1 (permalink)
Registered
 
Join Date: Sep 2006
Posts: 86
I'd say it's more likely that the pump lost prime than failed. Not sure how to reprime but maybe filling the filter canister would be a good start. I'd figure out for sure how to regain prime before starting again, though.
Old 11-14-2008, 06:26 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #2 (permalink)
Registered
 
Join Date: Mar 2007
Location: Florida
Posts: 86
Thanks for the suggestion. I've been researching the possibilities for this problem. The options range from the pump drive sprocket nut backing off and letting the sprocket slide off the oil pump shaft, or the sprocket shears off the splines on the oil pump shaft and spins (both of these are far more likely to happen) than the final oil pump failure. Unfortunately, none of these can be diagnosed without dropping the oil pan.

VAC has a neat solution for both of the above scenarios, plus they will rebuild your oil pump for you while they install (re-designed) pump shaft and sprocket. My car has 120K street miles on it, so the oil pump should be replaced or rebuilt if I going to drop the pan.

The gaskets and bolts for dropping the engine subframe and oil pan have been ordered from BMW, and an engine stand is on its way. You do need to support the front of the motor while the subframe is unbolted. All this gives you the clearance you need to remove the pan.

I'm also going to take advantage of this time, to install the racing oil pan baffle available for 95 M3. This insures that lateral "Gs" don't starve the oil pickup during long sweeping turns. We have a few of those in the Southeast.

I may try your idea, there is nothing to lose

One more thought, I must be the luckiest guy in the world. You may not understand that statement with all of the problems I'm having, however I can't imagine what my problems would be if the oil pressure went to 0 at 6500rpm on the back straight at Sebring

Last edited by mnichols; 11-14-2008 at 07:06 AM..
Old 11-14-2008, 07:03 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #3 (permalink)
Moderator
 
Jeron's Avatar
 
Join Date: Feb 2004
Location: DFW (Hurst), Texas
Posts: 4,730
Garage
It does seem to be a big coincidence. I would try again.

You have correctly identified the two most likely causes.

Those rebuilt oil pumps are expensive I dont think they are worth it, especially for a street car.

You dont "have" to replace any bolts to drop the sub-frame and pan.

You can make an engine support out of wood for a few dollars. You can buy a generic engine support for about $75. You also may be able to rent one at a local parts store.
http://www.amazon.com/ToolShopUSA-Engine-Support-Cap-660Lbs/dp/B000BVQ9NA

I hope the baffled pan works for you I have heard they are not very effective.

You should consider replacing the P/S hoses with bulk hose. After this repair they will probably leak. Make sure you you carefully mark the position of the steering column so you can recenter your steering wheel.
__________________
HPDE Instructor (BMW / PCA / Apex)
Here: 1997 M3/4 Byzanz/Magma ~ 2006 Yamaha R6 ~ 1997 R1100RT ~ 1991 Ford F-150 5.8l ~ 2015 Kia Optima
Gone: 2001 330i Silver/Grey ~ 98 Camry V6 ~ 97 Camry I4 ~ 97 Mazda 626 I4 ~ 93 Sentra SE-R ~ 88 Toyota Truck I4
Old 11-14-2008, 07:35 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #4 (permalink)
Registered
 
Join Date: Mar 2007
Location: Florida
Posts: 86
Jeron,

I have tried several times for an accumulated 1 minute of idle time. I don't really want to run it much more with no oil pressure. I've tried the priming the oil canister idea, and made sure I've opened the anti-flow back valves. No help. It really seems like the pump is not working.

I probably forgot to mention that the 120K street miles are in its past life, today its a dedicated track car. In my humble opinion the oil pump is the heart of this engine, and as long as I have the pan off I may as well either rebuild or replace the pump. They are extremely simple devices, so if the case is in good shape, then only the gears need to be replaced. I've priced both at the local BMW dealer, and they are not expensive. In fact a completely new oil pump is $400. The gears should cost me no more than $75-$100.

I appreciate your ideas on the PS hoses, good suggestion. They are leaking a little bit now, so they will be replaced. The Bentley book strongly suggests that the subframe bolts are one time use. They cost $4 each, I need 4 so I think replacing them is the best plan.

I really thought about making an engine support out of wood or other. But we have a Northern Tools shop in town, and I found a one ton engine hoist for $140. Yeah a bit more than a rental ($25 per day), and certainly more than a wood support, but now I have a nice tool for my future use, and my track friends as well.

I am a newbie on the baffle pans. I doubt there will be anyway to really how much they are helping once on the track. That is unless the oil pressure drops on hard corners.

Last edited by mnichols; 11-14-2008 at 11:02 AM..
Old 11-14-2008, 10:59 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #5 (permalink)
Moderator
 
Jeron's Avatar
 
Join Date: Feb 2004
Location: DFW (Hurst), Texas
Posts: 4,730
Garage
The engine hoist is a good item to own but it takes a lot of storage. The engine support brace is a lot smaller to store. The wooden homemade one is a bit big as well.

I loose oil pressure in one particular corner at a local track. I am concerned but haven't decided on a solution. I would like to get the euro dual pickup oil pump and pan. You might want to consider that even though the cost is high($1k-ish setup), you already have some sunk costs involved.

Order a drilled pump nut from Bimmerworld and get some Red or Blue loctite, unless you plan to weld yours on:
http://store.bimmerworld.com/shared/StoreFront/default.asp?CS=bimmerworl&StoreType=BtoC&Count1=239574611&Count2=156715035&Keyword=pump+nut&Target=products.asp
__________________
HPDE Instructor (BMW / PCA / Apex)
Here: 1997 M3/4 Byzanz/Magma ~ 2006 Yamaha R6 ~ 1997 R1100RT ~ 1991 Ford F-150 5.8l ~ 2015 Kia Optima
Gone: 2001 330i Silver/Grey ~ 98 Camry V6 ~ 97 Camry I4 ~ 97 Mazda 626 I4 ~ 93 Sentra SE-R ~ 88 Toyota Truck I4
Old 11-14-2008, 11:16 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #6 (permalink)
 
Registered
 
Join Date: Mar 2007
Location: Florida
Posts: 86
Thanks for the advice. The engine hoist is assembled and in the garage. Yes, it will take up some storage room, so I need to rearrange a few things. The drilled nut from bimmerworld was ordered earlier today, and I have red loctite on my shelves.

If you decide to go ahead with the dual oil pick up and pan let me know the results. For a weekend track guy this seems a bit much, but for racing I better understand the issue. So far my M3's oil pressure only wiggles a bit on a high speed sweeper (100+mph). It's never enough to trigger the 10PSI low oil pressure light. While I doubt I'm pulling anymore than .3 or .4 G's it gets my attention each time I go around it. If the baffle helps that, then its a winner.

What do you recommend for use as a sealer on the oil pan gasket?
Old 11-14-2008, 11:29 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #7 (permalink)
Registered
 
Join Date: Mar 2007
Location: Florida
Posts: 86
Well after dropping the engine subframe and steering rack, and finally getting near the oil pan, I managed to drop the pan and take a look at the oil pump. To my surprise, and perhaps disappointment the nut and gear were in good shape. The nut was still on the oil pump shaft and tight.

So I removed the oil pump and took it apart. Wow, the pump case and gears are scored as if they ran without oil. I don't know how bad the damage needs to be for the pump to quit pumping, but this is much worse than I expected.

I removed the front cyclinder rod cap to see if the rod bearings were damaged, but I don't see any issues with them. The rod bearings look good, worn after 120K miles, but worn evenly with no scoring. The crank journal looks ok as well, however I can see a very light scoring on the crank. Don't know if this is normal for a engine of this age or not. I plan to have a local BMW doctor stop by the house and look at the crank to see if there was any damage.

I wouldn't expect an oil pump to fail this way merely due to age. So I'm worried that I starved the pump of oil during my track runs. I have a stock oil pan, with no baffles or improvements. I'm certainly not going to re-install the pan without one of the baffle kits.

My next move is to use a plastigage to check rod bearing tolerances, just to assure myself that no damage was done, and to check the health of my 120K engine.




Old 11-16-2008, 01:47 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #8 (permalink)
Moderator
 
Jeron's Avatar
 
Join Date: Feb 2004
Location: DFW (Hurst), Texas
Posts: 4,730
Garage
Still no reason why no oil pressure? How is the pressure valve on the pump? The pickup tube is clear and clean.
__________________
HPDE Instructor (BMW / PCA / Apex)
Here: 1997 M3/4 Byzanz/Magma ~ 2006 Yamaha R6 ~ 1997 R1100RT ~ 1991 Ford F-150 5.8l ~ 2015 Kia Optima
Gone: 2001 330i Silver/Grey ~ 98 Camry V6 ~ 97 Camry I4 ~ 97 Mazda 626 I4 ~ 93 Sentra SE-R ~ 88 Toyota Truck I4
Old 11-17-2008, 08:11 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #9 (permalink)
Registered
 
Join Date: Mar 2007
Location: Florida
Posts: 86
The pressure valve on the pump is my prime suspect. I'm not real familiar with how the system works, I'm researching that now. I have one piston out of the oil pump housing, but I can still see another cylinder inside the pump (and signs that its been scored) where the other end of the spring sits. Is this supposed to move like the outer piston?

This piston is seized in the pump cylinder. I have a new pump coming from BMW, but I would still like to learn how this system works.

Old 11-17-2008, 08:51 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #10 (permalink)
Reply


 


All times are GMT -8. The time now is 12:02 PM.


 
Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2025, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2025 Pelican Parts, LLC - Posts may be archived for display on the Pelican Parts Website -    DMCA Registered Agent Contact Page
 

DTO Garage Plus vBulletin Plugins by Drive Thru Online, Inc.