Hey folks... Glad I found this forum tonight, as it might save me quite a few dollars. I have a 1987 300D which has been very good to me for the few years I've owned it, save for the past couple of weeks. About two or three weeks ago, that dreaded engine idling after I took out the key from the ignition started to occur. I took the car to my mechanic, (the only one in town, as I live in a very small and remote location in rural Virginia) and he pointed out that the vacuum pump was probably wearing out. Unfortunately, he wasn't able to look at in in-depth or fix it - the waiting time for an appointment was quite a long time. I've been driving it since then, waiting to get my darling car fixed. Two days ago, I started to notice a horrible rattling noise from the radiator area, so I left it at my work parking lot where it would be okay until the time for the mechanic visit. I started it up today, and the rattle continued. Hastily, I decided to try and make it back home. About a quarter-mile down the road, the car turned off completely after the oil and radiator lights popped on.

So, the car's back at the lot sitting until my appointment in a couple of days. Any suggestions? I am not a very hands-on person when it comes to car repair, but have seen vacuum pump repair kits that claim to be very easy to use... Help me - I would desparately like to bypass a very pricey fix if at all possible. What might be going wrong other than the pump? Thanks alot!

a rebuild kit for a pump is not very much , but if you are taking it to a shop they will probably want to put a new one on .You can look in FastLane and see what they cost.................

William Rogers............

I can think of two possibilities. One not so bad, and one very bad. After the car stalled, did you try to restart it? Did it restart?

Possibly the vacuum pump was failing, and that was why the car would not shut off. How were the power brakes during that time; they too are vacuum powered. If the vacuum pump was indeed failing, you would have manual brakes, the car would be exceedlingly difficult to stop. We're talking both feet on the brake pedal pushing as hard as you can. If the brakes worked normally, then the vacuum pump is fine and the shutoff problem lies elsewhere. That's good, as every other shutoff problem is less expensive than a vacuum pump.

The rattling could be from the tensioner for the fan belt. They do wear out. Have you looked under the hood to see if the fan belt is intact? If it breaks your alternator light will come on.

The worst case scenario is if the vacuum pump did indeed fail catstrophically. It is driven by the timing chain. Although rare, it is not unheard of for a failed vacuum pump to cause the timing chain to break. When the timing chain breaks, the engine stops and cannot be restarted. I'm concerned this is what has occurred on your car, as these diesels just never stall normally. A broken timing chain is a very bad problem; much internal engine damage generally results. I don't wish to alarm you, but the repair cost is very high. Hopefully this is not what has happened.

- JimY

The vacuum pump in an 87 300D cannot be rebuilt. You probably saw kits for the up to 85 300Ds.

When the serpentine belt tensioner shock gives, and usually it's the Heim ends that wear out rather than the hydraulic strut, it makes a noise that's easily mistaken for rod knock. Sounds like a rock inside the engine is trying to get out. A failing pump usually doesn't give much notice. The actuator arm ball bearings break free, jump around the retaining basket for a while, then make their way into the timing chain. It's not pretty after that. Your engine has a secondary compartment on the passenger side of the oil pan. It's pretty easy to remove the secondary compartment and check the bottom of the oil pan for debris. Drain the oil first.

I hope that your case turns out to be something simple. If you dodge the bullet, you'll have dodged a BIG bullet. I've yet to read of a vacuum pump failure in this type of engine that turned out to be something simple.

Sixto
95 S420
87 300SDL

Welcome to the forum...........

I hope too that your luck is with you on this. I had read in this forum some time ago about vacuum pump failure in these OM603 engines and the repercussion. Also I believe that these vac pumps had been improved, later, so as not to do damage if they failed.

Someone here may correct me if I heard wrong, and the new vac pumps could be identified by having 4 philips screws holding the vac pump face plate, the originally installed vac pumps had no face plate screws. Easy to identify if the vac pump had ever been replaced if you didn't know.

I checked to see if my vac pump had the 4 screws on my 87 300D and thankfully it did and had been replaced.

Steve..............

I know this is an old post but it will work for what I am looking for. Does this apply to newer pumps for 300SDs as well?

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1981 300SD 118K
2000 Toyata Tundra 64K

Are you referring to your 81 SD?

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It is a truism that almost any sect, cult, or religion will legislate its creed into law if it acquires the political power to do so. Robert A. Heinlein


09 Jetta TDI
1985 300D

My apologies, yes, my 81 300SD.

__________________
1981 300SD 118K
2000 Toyata Tundra 64K

Someone else today has vacuum pump problems. Your pump is similar to mine. More than likely, you just need a rebuild kit with check valves and seals. Not a bad job, it just takes a while to remove all of those allen screws around the outside. I rebuilt mine about a year ago.

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Sam

84 300SD 350K+ miles ( Blue Belle )

Thanks SD Blue. My question was more of whether the statement below applies to my 81 300SD as well. I am trying to figure out if am still running on my original or not.

"Someone here may correct me if I heard wrong, and the new vac pumps could be identified by having 4 philips screws holding the vac pump face plate, the originally installed vac pumps had no face plate screws. Easy to identify if the vac pump had ever been replaced if you didn't know

I checked to see if my vac pump had the 4 screws on my 87 300D and thankfully it did and had been replaced."

Thanks again.

__________________
1981 300SD 118K
2000 Toyata Tundra 64K

As far as I know, there were two different vacuum pumps for the 617's. The earlier type was actually a bit easier to work on if all you needed was a diaphragm. The later ones look larger and are a completely different shape and do not use a diaphragm.
I think you have the diaphragm type...Do a search in FastLane...subcategory is "Diesel Injection"...there you will see pics of the diaphragm.

To find your pump...follow the large black plastic vacuum line that goes into your power brake booster. You will find the pump down and to the left of the power steering pump.

__________________
It is a truism that almost any sect, cult, or religion will legislate its creed into law if it acquires the political power to do so. Robert A. Heinlein


09 Jetta TDI
1985 300D

Not shutting off with the key could be a lot of things, but it probably isn't the vac pump. You need to start testing the vac lines for a leak.

My problem was caused by this valve:
D2020-24917 Shut-Off Valve Metal Bosch IN STOCK

Now if you vac pump has the smooth cover on it you need to replace that before it destroys your engine. The new style has 4 screws on the cover. The old style pumps have exposed bearings that can fall into the timing chain and cause it to snap.

D3000-56042 Diesel Vacuum Pump Pierburg IN STOCK

I suspect this part is failing:
G6003-35686 Acc. Belt Tension Damper IN STOCK

They make tons of noise when the bushings go bad.

You will probably need a new belt and pully:
G6020-24744 Acc. Belt Idler Pulley Febi IN STOCK
W1000-21016 Multi Rib Belt Bando IN STOCK


One more thing, 603's don't like to overheat. Chances are you have an original "14" head on it. Do not ever allow the temp to get above 120C!!!!!!! It will cost you $2k+ if it does.
Only MB coolant and Zerox G-5 should be used.

Z8003-69600 Coolant/Antifreeze IN STOCK

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1999 SL500
1969 280SE
2023 Ram 1500
2007 Tiara 3200

Thanks everyone. That's the information I was looking for.

__________________
1981 300SD 118K
2000 Toyata Tundra 64K