The first person who solves this mystery gets my bottle of Tums. Because*I know some where down the line*I will have to return the favor and the tablets will have to do until I can resolve your issue. Ok here we go.

I have a very serious situation with my water pump RIGHT NOW! I'll spare you some steps for the sake of time .radiator out...fan off.. loosened the 2 belts ..pulleys off and old water pumps off (not *soooo fast.) This is where it gets interesting. I was doing this job at 3am and I had one more screw to undo. That screw was the one at the very bottom. I don't know what came over me but*I thought to myself maybe if I turn the engine one turn ( like you do when you adjust your valves)*that will get that screw to come to the top. DUH... what was I thinking.

First the pulley was not on the*water pump nor were the belts. Second of all, the*WHOLE*water pump doesn't turn (BOY was it getting late for me.) At any rate, I got the screw out and replaced the aftermarket (M183 water pump) with a M-B water pump.

Everything was going A O K. All I had to do now is put the pulley back on....Then NO GOOD started to happen. When I took the pulley off the first time I just pulled it straight*off. When I went to*place *it back on, I had to tilt it slightly to put it on the hub. Then that's when I noticed the PULLEY HAD DROPPED AND HAD MOVED FURTHER BACK TOWARDS THE BLOCK.

There was no way I could put the two belts back on, let alone put the fan on. I called the M-B parts dept. they swear they sent the right part for the car. However, they did some digging and they did tell me the previous owners of this car had switched the engine. **Engine in car now; 61795212015127.*Engine taken out: 61795212002110.

M-B parts dept. states this has nothing to do with the problem either.... THIS IS GETTING BAD. No body can tell me what went wrong; how to fix this easy routine water pump job; its approaching winter (car is outside; no way to get it into the garage.)

So Finally this is were it gets UGLY: The next day I go back outside and place a couple of bolts into the old water pump to mount it and* NOW the pulley still *doesn't fit correctly* ^^^^#$#%$$%$.* WHAT? If you don't' believe me see for yourself. And those Tums are still waiting for anybody who can solve this mystery.

Oh. one more thing.* After looking at the car's*water pump area at least 123 times, I saw that the*water pump housing* had gouges inside of it. But the old water pump itself*did not show*any signs of metal shaving or rubbing metal against metal.*

So now I need anyone - everyone -to put your heads together and come up with a solution to my water pump problem...THANK You

Attached Thumbnails

   

To summarize, with the old pump the pulley fits fine, with the new pump it doesn't?

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Prost!

YES and NO....when I First took the aftermarket wp off(everthing is starting to get garbbled in brain now) I remember just being able to pull the pulley towards me with out a problem. When I put M-B wp on the pulley was in wrong position. I have had some people tell me the pulleys in the right position.(I think they have me convinced 2+2=6) At any rate when I tried to put the old /aftermarket wp back on with a couple of bolts...I quickly realized the pulley was still in the same (WRONG) place. I have to tilt the pulley to get it on shaft. Everything(Pulley,belts) looks likes its sitting on top of each other.

with all the info I'm gathering now. I'm not sure if pulley was ever in the right place to begin with. read my latest post. With gouged fan shroud, belts with no tread.Hmmm Not sure if this is a wp problem any more

I'm trying to understand what the heck is going on too.

It sounds like the new pump bolts up to the engine but the pulley does not fit - and it does not line up with the existing "lines" in which the belts have to run.

First step =>

Compare the "heights" of the water pumps - does the old one stick out further from the block?

There are different pulley options out there - you could be suffering from a bit of a swap around

__________________
1992 W201 190E 1.8 171,000 km - Daily driver
1981 W123 300D ~ 100,000 miles / 160,000 km - project car stripped to the bone
1965 Land Rover Series 2a Station Wagon CIS recovery therapy!
1961 Volvo PV544 Bare metal rat rod-ish thing

I'm here to chat about cars and to help others - I'm not here "to always be right" like an internet warrior



Don't leave that there - I'll take it to bits!

Been a great "Fan" yours S ....love your restores( no pun intended) because the fan won't fit onto the pulley.LOL I don't know the history of this car. That's why I have been changing belts and hoses, liquids etc..M-B classic told me that my 300td had an engine swap...But that should not make a difference. The aftermarket pump that was on the car should not make a difference.I checked wp and have pics if you want to see they are the same length,but how doe the pulley DROP DOWN? I've recently been told by someone that my engine is a mid 80's engine. And my engine has 2 types of water pumps. But this still does not count for the fact that I tried to put the old wp back on and the pulley didn't fit in the proper place. Explain That? DO YOU THINK ME Turning THE ENGINE over 1 turn OR HAVING THE CAR ON JACKS HAS ANYTHING TO DO WITH THIS?

If this is the case and I do believe it may be pulley swap. 1st How will I know? Remember the engine has been replaced. 2nd If I find out this is true what are the steps I must do to resolve this issue?

Those water pumps are supplied in two different lengths; as Stretch advises, put the two side by side.

The problem is not logical at all.
Is there possibly an axial play and as you mount the old pump pushes the shaft outward?
It seems there is about an 1/8" clearance missing, too far out, I could be wrong with the distance.
Are the mounting flanges identical in thickness?
Was the new pump not turning or the old one?
Is the pump housing (forgive me for asking) in the correct position?
Is the pump perpenticular to the motor block?
Since the problem now also exists with the old pump, the lenght may be correct.
Now, this is far fetched, is there a shim inside the pulley?
I think there is some weird seating problem, if all dimensions are the same.

__________________
Mostly, I don't know notin, I just know where to look.
I am looking back, to over 30 years in Electronics Design.
Electrons don't care if they move in a car, computer or relay!

95 W124 E320 M104.992 - Because, I love to repair, naaaah!
Over 221,000 Miles
Cheers,
Norbert

I would also check to see if someone has placed a shim (washer) on the inside of the pulley.

I'm going to try to answer all your questions as best I can.
*Both Pumps are turning. the after market...seemed to be a little on the wimpy side as far as weight...MB wp just seemed a little more beefier. the turn of the after market seemed smoother( could be because of bearings/a lot of use) MB not as smooth/harder to turn to me.
**the pumps are the same height/MB states that aftermarket or not wp should fit.
**wp appears to be perpendicular to block
** I did not notice a shim when I took the fan off and I did not notice a shim when I took the pulley off
***Not sure about the pump housing and if its in the right position.How can I tell?
Check my new post for more problems to this problem that may help you solve all my problems..Please

You are feeling seal drag, this can vary with a bit of lube / water on the seal faces. Not a really a good test for anything. Rough would indicate failing bearings.

tc_1:

If the picture of the pump which you have posted is of the new pump, it would appear that the drive flange (where the pulleys and fan are attached) is unusually thick. A short pump body assembled with a long shaft and a thick flange would be the same length as a long body pump with a thin flange. The overall length from mounting flange to pulley flange is the critical dimension; it should be the same for both the old pump and the new.

(Sorry but I'm not 100% sure what exactly is going on with this thread)

But I think the problem is that it is as though the distance between centre of the water pump pulley and the centre of the crankshaft pulley is not big enough.

Please correct me if I have got this wrong.

If I'm right in thinking that the problem is as I have said then I would be looking at the crank pulley as well. It is not unknown for a crank pulley to fall off the front of an OM617...

I can measure the distance between the centres of these pulleys if necessary

__________________
1992 W201 190E 1.8 171,000 km - Daily driver
1981 W123 300D ~ 100,000 miles / 160,000 km - project car stripped to the bone
1965 Land Rover Series 2a Station Wagon CIS recovery therapy!
1961 Volvo PV544 Bare metal rat rod-ish thing

I'm here to chat about cars and to help others - I'm not here "to always be right" like an internet warrior



Don't leave that there - I'll take it to bits!

I may be pointing out the obvious here, but here goes.
I recently changed out a water pump on an M104 and I noticed that the puleys for the water pump and the power steering pumps were identical, except....
They are mounted in the reverse direction.
What I mean is that the pulleys have an offset between the flange face and the grooved outer ring. They can be mounted with the offset either toward the engine or toward the radiator. Have you tried reversing the pulley ?
Another interesting finding was that the bolts holding the pulleys to the pumps had 1/2" heads (a 13 mm wrench was too big) and were painted red.

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1990 300CE-24 (Gone but not forgotten)
2002 SLK 32 AMG
2002 ML320 (Gone)
1995 E320 Cabriolet