Oil pressure gone to zero - Page 2 - PeachParts Mercedes-Benz Forum

t walgamuth · #16 11-26-2009, 04:59 PM

Quote:

Originally Posted by GregMN

Oil pump sprocket, not gear.

Yes, it is directly behind the harmonic balancer, it is probably in the timing case cover. I didn't even think about that area being the timing case cover. I was sad and tired, so I went to bed.

The small bolts probably are from the oil scraper, but I think that they were just sitting in the bottom of the pan and had nothing to do with this incident.

I still don't know what caused this yet.

The first photo is the parts found in the pan.
The second photo shows the hole in the cover.

Reread the first paragraph in my post just above.

A loose nut or washer bouncing around in the oil pan can be sucked up against the screen and in time the action of it moving around will cut the screen and allow the bolt to enter the oil pump and lock it up.

Larry Perkins I believe is the name of the fellow who wrote about this regarding the 3.5 603 motor. It is the only one with a bolted together scraper, IIRC.

Those nuts and so forth in your pan do not belong there and may well be the culprits in your case.

GregMN · #17 11-27-2009, 11:13 AM

I am beginning to think that is what happened. The sheared off bolt, bent teeth on the sprocket, broken roller on the chain, all point to the engine turning at 2800 rpm and the oil pump suddenly not turning at any rpm.

I will pull the oil pump in a little while and report back.

GregMN · #18 11-27-2009, 12:44 PM

Alex Trebek: what Jeopardy category and amount?

t walgamuth: I will take "engine lubrication" for $1000 please.

Alex Trebek: The answer is "parts sitting harmlessly in the oil pan".

t walgamuth: "What phrase is GregMN likely to never say again in his life".

Alex Trebek: CORRECT!

(I hate being the poster child for problems like this.)

In the photo you can see the oil pump pickup screen with a hole in it just about the right size for the washer that I found in the pump to fit through.

So. I need an oil pump, new sprocket, new chain, and a timing cover.

Does anyone recognize that washer and know where it may have come from?

t walgamuth · #19 11-27-2009, 12:54 PM

Wonderful....please send my $1000 to the following address....

I am hopeful that you got lucky and did not damage the bearings and crank. It is possible.

Good luck!

(By the way, I did not believe it was possible either, but Larry convinced me!)

GregMN · #20 11-27-2009, 05:39 PM

In the image, in post #15, of the items found in the pan:

The 2 short bolts are from the oil tray. I found were they go. I will be removing them all and reinstalling with loc-tite.

The chain roller is from the oil pump chain.

The larger washer, I think, is from the bolt that held the sprocket on.

The smaller washer is the same as the one that jammed the pump gears. So there were 2 of the them. Where did they come from?

#21 11-27-2009, 05:51 PM

Does this help:

GregMN · #22 12-03-2009, 01:02 PM

As Paul Harvey would say " and now you know the rest of the story ". I now know what happened and why (sort of).

Look at the photo on post #15 of the parts found in the oil pan.
Look at the photo on post #18 of the oil pump suction screen and the washer found inside the pump.

The 2 small bolts found in the oil pan were 2 of 6 bolts used to hold the oil tray in place just under the crankshaft.
The 2 thick washers, one found jammed in the oil pump and one still in the oil pan, were spacers that go between the oil tray and the main bearing bolt heads that the small bolts screw into.

So, 2 bolts worked loose and the spacers eventually worked out. I do not know how long this took and then how long they set in the bottom of the pan (not harmlessly). I put loc-tite on the bolts and replaced them. I removed the other bolts and put loc-tite on them.

The other 4 bolts were finger loose. Since this forum is not full of people with jammed oil pumps from loose parts floating around in their oil pans, it is not something that failed from the factory. Somebody screwed up, more to the point didn't finish screwing in. They put the bolts in finger tight and went on break, came back from break and put the pan back on. Since all the work was done at the MB dealer in Fargo, ND, I should be able to find out when the oil pan was last off. It might be worth a day trip, and 18 gallons of WVO to find out.

Thanks for everyone's help so far. I should have all the parts here by Monday. I will let you know when it is back on the road.

GregMN · #23 12-08-2009, 05:13 PM

It is back together and running. Seems fine. Oil pressure is where it was before.

Thanks Phil for the used pump and timing cover.

engatwork · #24 12-08-2009, 07:44 PM

Good job Greg.

compu_85 · #25 12-08-2009, 07:50 PM

I've heard of this failure before on the 350s. I wonder if its worth dropping my pan and putting some red or black locktite on the bolts... Can you drop the pan with the motor in the car?

-Jason

GregMN · #26 12-08-2009, 10:06 PM

The motor must be lifted about 3" at the cross member. Remove the allen head bolt from each motor mount from below. Disconnect the motor mount shocks at the bottom. Disconnect the fan shroud so it can move with the fan. Disconnect the steering shock absorber. Remove the cross member under the front of the transmission. Use an engine hoist to lift the motor by the front lift point until you can pull the pan out.

I was also removing the timing cover. I could R&R the head faster and easier than the job I just did.

If you are worried about a loose fastener getting sucked up into the oil pump, glue a reasonably powerful magnet to the outside, bottom, of the pan, and hope for the best.

compu_85 · #27 12-09-2009, 07:39 AM

I like the magnet idea

layback40 · #28 01-28-2010, 09:39 PM

X2, compu

Most old front wheel drive BMC cars (mini etc) had a sump bolt with a long rod magnet protruding from the middle of it.
I have often thought of getting one of these magnets , drilling into the center of the sump plug & pressing the magnet in.
I can remember seeing some of these magnetic plugs at oil changes, covered in fine metal , Even saw one with a ball bearing stuck to it. Admittedly the BMC's sump had the gear box in it.

cscmc1 · #29 01-29-2010, 10:52 AM

Greg -- glad to read that you got (or are getting) this sorted out. Isn't it great when you have the resources to track this kind of mystery down, and ultimately solve a problem? I love my W124 300D, but there is no way I would be able to own and maintain such a car w/o the PeachParts forums. Gotta love the internet (and Phil, for sponsoring the forum, and the VERY helpful members here).

Anyway, glad things are working out. Hope you get your car back on the road pronto, and that she provides many more miles of healthy service!

rkpatt · #30 02-13-2010, 08:49 AM

I just purchased a 240k mile 300d OM602 and am contemplating refastening the oil pump sprocket bolt (w/locktite) and replacing the vacuum pump as PM items .

The timing chain is within spec . I wonder if it can go anyway ?

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