603 Injector Pump Leaking Oil - PeachParts Mercedes-Benz Forum

stephenson · #1 10-06-2003, 11:43 AM

I can see drops on the bottom of the IP and engine oil is building up in the (unintentional) reservoirs formed by the aluminum engine mounts under the IP.

It started when I changed to Rotella T syn from my normal Mobil 1 ... I changed back and it reduced the leak a lot, but appears to be increasing now (another 10K has passed).

I can continue to sop up the stuff with papertowels (maybe 10 ccs a fillup) .... or, devise a not so cool container of sorts to catch the oil as it drips.

Options:

1. Change to Delvac 1 with the hope it has more seal swellers
2. Pull IP and replace the gasket

Option 1 is easy ... Option 2 is painful (I think).

How big a deal is Option 2? Can I do it in a weekend? Am pretty proficient, but perhaps this is best left to pro? I hate the idea of anyone working on my car, but am sensitive to not being too focused on this to the detriment of "doing the right thing."

Advice, please!!

lrg · #2 10-07-2003, 12:07 PM

I'm not sure about the later 603s but on my '87 there is a rectangular cad colored plate that is screwed onto the side of the IP with 4 or 5 screws. On my car the rubber gasket behind it had hardened and I got a slow dripping leak. Since the plate is easy to access and the gasket cheap, try replacing this first and see if it helps. I got lucky and it stopped my leaking.

BobK · #3 10-07-2003, 12:36 PM

I have replaced the input seals on VW injection pumps before. Not too bad a job, but not always what is really needed. Some times the the seal fails because the bushing behind it is worn and the shaft is moving around a bit. Some folks are willing to dig into an injection pumpfar enough to replace the bushing, but I don't have the nerve or the manuals to do it.

#4 10-07-2003, 04:16 PM

lrg,

I have a possible leaking IP and like your hopeful remedy.

Where on the pump is that plate and where did you get the gasket from.

I hope that my leak is no big deal like yours was.

Thanks

bob c

lrg · #5 10-07-2003, 04:46 PM

The plate is on the outboard side of the IP, roughly 1" x 3" and held on by 4 or 5 slotted screws (I can't remember exactly and my wife has the car), you can't miss it. The screws are a bit tough to get at with a regular screwdriver but if you have an angle screwdriver you can get at them easily. I got a new gasket at the dealer - they had to order it but got it in a couple of days. The gasket is made out of a fairly soft material and my old one was hard and brittle when I removed it. A little bit of oil will dribble out when you remove the plate but otherwise it is a 10-15 minute job.

#6 10-07-2003, 07:05 PM

Thank you,

My car is at the shop now and we shall see what they say about it.

I am getting the transmission seals fixed.

I spoke with my mercedes guru and he said that the injector pumps leaking are common. he said that the bottom plate was hard to fix but the side one is easy. I have ordered the gasket so we shall see how it goes.

thanks again

bob c

gsxr · #7 10-08-2003, 06:57 PM

The side plate gasket is the only easy one to replace. And sadly, it's the least likely to leak enough to drip. The bottom plate is the worst, usually, and is almost impossible to do with the pump in the car. Much easier to pull the pump - and while it's out, replace ALL the external seals, and the vacuum shutoff pod too (if not relatively new). There are 7 total, they cost a few bucks each:

1- Bottom plate O-ring
2- Side plate gasket
3- Round ELR O-ring (rear)
4- Governor plate gasket (rear)
5- Vac shutoff pod O-ring (top)
6- Pump-to-block O-ring
7- Fuel lift pump gasket (optional)

The shutoff lever shaft O-ring is another common leak, but that seal isn't available from MB, you need to buy it from Bosch. It's nice to have a totally dry pump when you're all done though. The job requires removal of the vacuum pump (and a new gasket), the MB pump lock tool (about $30), and is much easier if you remove the intake manifold (not that hard, plus it's an excuse to clean it & install new gaskets with Hylomar sealer.)

HTH,

stephenson · #8 10-08-2003, 11:30 PM

gsxr,

So, you think it is likely the bottom one ... is there ANY chance of doing it on the car? I don't have time to get into IP R&R right now ... has anyone ever done it on the car?

Thanks to everyone for comments!

gsxr · #9 10-08-2003, 11:56 PM

I was told that it is possible - but I don't see how. Be warned that the IP is filled with engine oil, and if you remove that plate you'll get a bath with about a half-pint of black goo.

The problem is, it's hard to get a tool on all 6 screws that fasten the bottom plate. If you can get something on all 6 and crack them loose, it should be possible to replace the seal. Plan on a couple of hours of cussing at it. Please post the results if you try to do it, I'm very curious what your report will be!

sixto · #10 10-09-2003, 02:12 AM

Dave,

I have a leaky engine stop lever shaft seal. Can this real be replaced from the outside? If so, do you have the Bosch part number?

Thanks,
Sixto
95 S420
91 300SE
87 300SDL
83 300SD

#11 10-09-2003, 10:00 AM

Hey folks,

It seems that we have found a hot topic.

THe job seems pretty challanging.

To remove and refirbish the pump seems like a good idea but what about the timing and all that stuff.

I am going to have my intake manifold off this weekend (if my bro sends me my parts, works at a dealer)

I am tempted to pull the IP but am fearful when I thnk what larry bible did with his. His car raced when he started it up so badly that I think he did some damage.

Much research will be done.

I might just live with the leaks

thanks

bob c

gsxr · #12 10-09-2003, 10:46 AM

Sixto,

I *think* it can be done externally. Unfortunately I don't have the Bosch part number. I was planning on calling Bosch and having them fax me the exploded view drawing for the pump with the parts list, and then trying to find a shop that would sell me the parts. If cheap enough, I was going to buy a batch of the oddball stuff like that shaft seal, the ALDA seals (to rebuild the ALDA), etc and maybe sell a "kit" for others who need to do the work. One more thing I haven't had time for.

Bob C,

For the OM603 engine, timing isn't a big issue. You need the $30 lock tool as I mentioned earlier. This keeps the IP locked in place when you remove it. Just don't touch the engine. You'll need the timing basket, which hopefully is still in place behind your vacuum pump. Oh and btw if your VP is original (no Torx screws in the front cover), it should be replaced immediately! The originals were time bombs.

Larry Bible had a problem when replacing the *vacuum shutoff* pod on a 617 engine. If you don't touch the vac pod, you won't have this problem. Also, on a 603 engine, you can TEST the vac pod after you R&R it. Use a MityVac and make sure the stop lever moves through the *complete* range of travel as it did before you touched it. If you do this, you'll be fine - no worries. But pulling the IP is a several hour job, requires the special tool (special order from the dealer or Caliber Motors), and requires all the gaskets & seals (special order from the dealer, FastLane, or Rusty).

#13 10-09-2003, 12:11 PM

I concur with EVERYTHING Dave M. (gsxr) said but will add that I have successfully tightened the side plate screws and eliminated the leak from the pump on my 603.960 engine (I have the gasket but haven't needed to use it). I don't see how you can reach more than a couple of the screw on the bottom of the pump without removing the pump and the rear screws are tough to reach as well!

If the pump wasn't leaking when using Mobil 1 or Delvac 1 and started leaking when Shell syn. was used - I'd switch back to Mobil, BUT it usually takes months for the sealing properties of the Mobil synthetic to eliminate the leak (if it EVER does). On one of my engines that as switched back to conventional oil and started leaking, the leak first got worse when I switched back to Mobil synthetics but it sealed within a year. The other engine never completely sealed again (I got rid of that engine a year or two later).

Marshall

#14 10-09-2003, 02:57 PM

Thanks for you help.

THe shop told me that the injector pump was leakiing and that it would cost me 450 to remove it and 600 plus for bosch to rebuild it. After discussing it with him he assured me that the car was in no danger due to the leak and that it was nothing more than a nuasance. Kudos to him not giving me another big job to pay for.
I will try tighnen the gasket down as mentioned before I pull the timing belt.
One question (and not a nother oil thread). I just bought some rotalla synthetic from wal mart for 11.50 a gallon. Is mobil delvac one going to do a better job sealing leaks than the rotella. I know that I should pull out the IP if I want it done right but sometimes simple solutions are the best.

The SHop is Manfred in Cary, IL. He is charging me 600 to replace the tranny seals including front pump. I am happy with that price as I know that they have done many before. The dealer wanted 1600 or more.

Thanks again for some great advice with my car. IF any one is ever on the north west suburbs of chicago look me up. I buy you a cup of coffee. The people of this forum are very generous with their time and knowledge. I greatly appreciate it.

Thanks

bob c

#15 10-09-2003, 03:30 PM

Rotella "synthetic" has been linked to increased leaking. I have not tested it myself since I have no applications that are satisfied by hydrocracked oil and am particularly offended when oil that is largely "cheap" hydrocracked conventional oil is labeled and marketed as "synthetic."

Mobil synthetics (Mobil 1 and Delvac 1) have an additive package that will repair/prevent modest seal leaks. This may NOT occur immediately - one of mine took nearly a year to seal.

Marshall