Walked out to my 300SE and noticed a puddle of water under it. However, it wasn't something easy like a hose, it was dripping down the oil pan. Here is a picture of the depressing sight.



I'm guessing it's the weep hole, can't see any coolant from above. How long do I have before the bearings eventually seize?

If I do have to replace the water pump, I'll probably do it myself. But reading a lot of the posts on the m103 water pump is scaring the crap out of me. Looks pretty hard.

Don't let it scare you.
Based on mileage and if it has ever been changed or not plan on replacing the tensioner and the tensioner shock. More pia type job than anything to be scared of.

__________________
Jim

no telling.... better change it asap.

tom w

__________________
[SIGPIC] Diesel loving autocrossing grandpa Architect. 08 Dodge 3/4 ton with Cummins & six speed; I have had about 35 benzes. I have a 39 Studebaker Coupe Express pickup in which I have had installed a 617 turbo and a five speed manual.[SIGPIC]

..I also have a 427 Cobra replica with an aluminum chassis.

6 hours.

Make sure of the following:

loosen the center bolt on the tensioner FIRST or you will be buying a new tensioner rod...

If you have more than 75,000 miles since the last tensioner replacement, buy one now, else you will be sitting with an unusable car until you get one. When loosening the tensioner, watch the pointer. If it moves back to near the start of the "ramp" cast in the tensioner, you can re-use it. If it doesn't move, or only goes part way back, the tensioner is shot (and yours is very likely dead).

You will have to pull the tensioner shock up with the belt to get it back on, it tends to run out to full extension and makes the belt look too short.

Not a bad job, just messy and long.

You will need a swivel to get the wp off the head and back on. This would be very easy except for the PS pump in the way....

Make sure you fill the engine with coolant and purge the air correctly before driving, else you will fry the engine (I nearly did) -- pour coolant into the reservior until full, the squash the upper rad hose flat with one hand, then crimp the overflow line from the rad to the tank shut with the other. Release the upper rad hose, coolant will be sucked up into the engine. Repeat, filling the tank when it goes dry, until no more coolant gets sucked in. You will still be quite a bit short after a couple heat/cool cycles, but it won't overheat.

Peter

__________________
1972 220D ?? miles
1988 300E 200,012
1987 300D Turbo killed 9/25/07, 275,000 miles
1985 Volvo 740 GLE Turobodiesel 218,000
1972 280 SE 4.5 165, 000 - It runs!

Good advise from Jim and PS Fred.

Over the years, there has been a lot of yack here about buying some special Snap-On swivel tool. If you make a living replacing 103 water pumps, go buy it, else just follow the procedure in the 103 engine manual or whichever CD you have(same thing).

As stated above, this might be a good time to change out the tensioner, shock, etc.

This is not a hard job, but it does require removing a lot of pieces and if you're not into that, let someone else do it.

__________________
Mike Murrell
1991 300-SEL - Model 126
M103 - SOHC
"Fräulein"

Well I just changed my serp belt a week or two ago, and the tensioner was fine, so I think I'm safe there. I have no problem removing a lot of stuff, I just refinished all the wood in the interior, and remembering where everything goes will probably be easier during the water pump job. Just need to find a mode of back up transportation in case this ends up taking longer then it should. What brand of water pump should I use? I'll probably order from fastlane, looks like there are three different brands.

And I've read about some trouble with converting over to the new WP design? I have a 1990, so I believe it won't be a problem. Don't know if the WP has been replaced before, I'll have to go through the service history. I doubt it has.

I just did a coolant flush recently too, so I won't have to go out and spend $50 at benz. Hooray.

I had replaced the belt last month and then the tensioner was OK.
I also had the coolant flushed.
Now the water pump was leaking and had to be replaced. Had to replace the tensioner and shock too.
The coolant temp shows 100 c and above most of the time. Looks like I will have to check for air blocks as described by psfred.

__________________
300CE 1989 Euro Model.
ML350 2011.

When I did my water pump last year, I bought the Laso. Still seems to work alright, although I would check on what the MB part is going for, in case it's not too much more.

Your car probably has the updated hose connections for the new water pump design. I think the breakpoint was somewhere around '87 or '88.

I would also seriously consider buying the Snap On tool. You don't have to, but considering that doing this job yourself probably saves you about $500 in labor charges, the $50 for the tool is well worth it. It only swivels in one axis, making it more stable than a universal, and it has a really short socket, which lets it get into all sorts of places that a conventional socket + u-joint struggles with. Oh, and it's a 12-point socket too.

Two days ago, I also observed some coolant on the floor which had dripped down onto the oil pan plug. Similar to this thread's picture. I topped up the water reservoir with three std glasses of water.

I dried up the oil pan area and ran the car about 15 miles on an errand (monitoring for trouble and checking under car after parking.).

Back home I popped hood and got under car with flashlight. All is dry. No repeat drip. Engine temp normal. Dry at all areas of coolant system.

Question, I do suspect that the water pump will or is on the out. (132K miles)

BUT, can the water pump weep as a purge ??? i.e. designed to do this under some circumstances????

I want to continue monitoring before acting on a replacement pump and all the other replacement parts that ought to go in suit.

Thanks

__________________
1979 300D 220 K miles
1995 C280 109 K miles
1992 Cadillac Eldorado Touring Coupe 57K miles SOLD
********************
1979 240D 140Kmiles (bought for parents) *SOLD.
SAN FRANCISCO/(*San Diego)
1989 300SE 148 K miles *SOLD

I could not do this job without a 1/4 inch 13mm socket and wobble extension... . it was for the two back bolts, top and bottom.

The socket was inexpensive... I tried for 90 minutes to get the top back bolt with a 3/8 socket but no luck...just not enough room

i opted out of the snap on tool. i think the 13mm cost me 6 dollars.. i had the wobbles

i had to do two of these within weeks of each other....one car needed the tensioner, the other did not. 6 hours is about right. Someone claims they can do one in a couple of hours..but i don't see how.

do yourself a favor and take the radiator out first... it doesn't take very long and it buys you space and piece of mind.

Be careful on the power steering pump... if you pull the wrong bolts.. you will have ps fluid all over the place. Ask me how I know.

__________________
1989 300ce 129k
( facelifted front,updated tail lights, lowered suspension,bilstein sports, lorinser front spoiler, MOMO steering wheel, remus exhaust,stainless steel brake lines). (Gone)

1997 s320 154k (what a ride). Sold with 179k miles. Replaced with Hyundai Equus

1994 e320 Cabriolet 108k



1972 280se 4.5 153k Owned for 12 yrs, sorry I sold it


[/SIGPIC]

My W124 300E leaked coolant for a day then stopped for a week before starting again.
My leak was coming from the o-ring between the pump and the block but as the car had done 260000kms, I put a new pump on anyway.
Took me just under 2 hours including a trip to the hardware store for some rubber grease.

__________________
Tony
76 W116 280SE
74 W107 450SLC
88 W124 300E
82 W123 280TE

Not necessary on a 126 car with a 103 motor - 300SE/300SEL.

__________________
Mike Murrell
1991 300-SEL - Model 126
M103 - SOHC
"Fräulein"

I didn't remove the radiator on my 124 either, but I did slide a piece of cardbord down to protect it while working.

__________________
Tony
76 W116 280SE
74 W107 450SLC
88 W124 300E
82 W123 280TE

what does this Snap On tool looks like? are there pictures of it on the web?

Look that tensioner over really close.
The only time in 17 years "Old Pearl" let me down was when the tensioner suddenly broke 90 miles from home. I had no choice but to pay $360 for a dealer part, and replaced it in a parking lot.

But wait, there's more:

That's when the wife insisted we not take Pearl out of town again, and it cost me another $40k for a new car!

DG