Water pump leak. 1993 400e m119 engine - PeachParts Mercedes-Benz Forum

umpqua101 · #1 10-02-2010, 06:12 PM

My 1993 400e has a leaking water pump. The Mercedes dealer quoted $1,843 to replace the pump, one hose and the belt. This sounds way out of wack. They say 800 for parts and 900 for labor. The rest is tax.

My second question is; how long will a leaking water pump survive? Or will it self destruct in a short time. Right now I drive about 24 miles without overheating, park for 8 hours and then fill the reservoir with half a quart of water. Repeat. This has been for the last week.

emerydc8 · #2 10-02-2010, 11:09 PM

I changed a water pump on my 1993 400E and found some additional work was required that I did not contemplate. In order to get one of the pump bolts out, I had to remove the crankshaft damper. There is one bolt that is about 3 inches long and the damper interferes with pulling the bolt completely out.

I am told that most Mercedes have either a hole in the damper that allows you to remove the water pump bolts, or the damper can be "walked" off the crankshaft hub after loosening the five or six smaller bolts that hold the damper to the crankshaft hub.

But on my 400E, the only way to get the damper off was to remove the big bolt in the center that goes into the crankshaft (I think it took a 27 mm socket). This bolt is torqued to several hundred foot-pounds and I was told that loosening it would create a high chance that the crank seal could leak unless the hub was extracted and the seal was replaced. This takes additional time and a special tool to extract the hub and install the seal. You may also have to heat the hub up with a torch to expand it so it will slip back onto the crank when you reinstall it. I think the manual calls for this.

In any case, in order to remove the crank bolt, you will have to inhibit the crank from turning as you loosen and tighten the bolt. The option is to remove the starter and insert a special tool that locks the crank, or some people just pull one of the bolts out of the torque converter and insert a homemade hardened bolt and sleeve to keep the crank from turning during the loosening and tightening process. The removal of the damper might be the reason for the high labor charges.

Of course, the dealer will always be the highest quote you can get, so I'm sure you could find an independent Mercedes repair shop to beat that price.

I think it would take a crystal ball to determine how long your leaking pump will last, but keep in mind that if you keep adding just water, it may dilute your anti-freeze/water mixture down to the point that the cooling system would be adversely affected. Some people also contend that anti-freeze provides lubrication for the pump, although I'm not really sure this is true.

Are you sure it's the pump and not just a hose that's leaking? My pump had about 200,000 miles on it and it wasn't even leaking. I just changed it because I thought it must have been worn out with that many miles.

If the pump is original, there should be a drain line about a foot long that goes from the weep hole into a small recovery tank. I can't remember exactly what it looked like, but I was told that it was not necessary and no one ever replaces this hard brittle plastic line when they replace the pump. Is the pump leaking from this line?

emerydc8 · #3 10-02-2010, 11:52 PM

Here is the picture of the "cooling water outlet line" I mentioned in the previous post. It is #110 in the picture. It is hard to tell from the picture, but the plastic line (about 3/8" in diameter) runs directly under the water pump. The recovery tank is at the bottom of the line and if I recall it is mounted to the front base of the oil sump.

I am presuming this was some sort of environmental effort to collect any leaking anti-freeze that came out of the weep hole. If someone else knows the reason for this line, please fell free to chime in.

umpqua101 · #4 10-03-2010, 05:01 AM

I am going on the mechanic's report from the dealer. Do not know how they test the coolant system for leaks.

The report says coolant is pouring out and should be towed from the dealership if not repaired. I'm sure this is CYA

Right now I use about 1/2 litre of water per trip and a few hours of being parked. I just fill the res and go. I know I'm on borrowed time while I put the money together.

Parts prices from non Mercedes suppliers seem to be less than $400.

When I was young, 60's and 70's, I had a similar problem and lasted for quite a while. I'm concerned about a quick disintegration of the pump.

emerydc8 · #5 10-03-2010, 07:44 AM

I would dig further into specifically where they say the water pump is leaking. I hate to say this about dealers, but they tend to take a shotgun approach when it comes to coolant leaks, especially if the service manager thinks you are not a DIYer and he can get away with it.

My neighbor was a diehard Mercedes owner until he took his 300E to the dealer for a coolant leak. They replaced the entire cooling system (radiator, hoses, water pump, belt, thermostat) for $1,800 and they didn't even tell him they were going to do all the work. I guess they just presumed that because he was in his sixties and was well dressed, they could charge him the max (his wife was wearing some expensive looking jewelry too).

He was so mad when he picked up the car that he drove it from the Mercedes dealer directly to the Lexus dealer and traded it in towards an LS400. Every two years, he buys a new LS 4xx. It was Mercedes' loss.

See if they can put it on the rack and show you where the leak is coming from. To the extent they cannot (or will not) show you, I would think about taking it for a second opinion.

If you decide to drive it off, make sure the warning light for the coolant level is working (observe the light comes on with the others when you turn the key). Assuming you have at least the minimum coolant and the temperature is within normal limits, I don't see how this could hurt the engine. Just be prepared to pull over and turn the engine off if the low level light comes on and/or the temperature starts to get over 110 degrees. If you let it overheat, you could warp the heads and that would cost more than the car is worth.

lee polowczuk · #6 10-13-2010, 03:11 PM

i just went and looked at a 400e.... the water pump is a piece of cake compared to the 300e...

400e water pump just over 100 dollars.....maybe 120 tops

Ferdman · #7 10-13-2010, 06:13 PM

Buy a reconditioned water pump from your local MB dealer. Replace the leaking water pump immediately before you overheat the engine and compound your problem. Recommend replacing the thermostat and any hoses that are questionable.

umpqua101 · #8 01-02-2011, 12:12 PM

Here is an update to my original question of leaking water pump.

I found an independent Mercedes shop to do the work at half the price of the MB dealer. The parts may not be MB but are supposedly from the same manufacture. The quote for replacing the pump was $750 including parts and labor. The job would be about 4 hours, so my car would be in and out in one day. The pump was $450. I found out that the pump seal goes bad but the bearing never does. Not like the old days of the 50's and 60's.

However, at my son's insistence to have the timing chain replaced and the reaction of the shop owner (oh god) when told the car has 236,000 miles on it. I decided to have the chain replaced too. If the job was done in conjunction with the water pump that would be an additional $850. By pulling the valve cover, the top chain guides, tensioner and chain can be replaced. BUT, the guides were shot with broken pieces about. The only way to do the job correctly is to pull the front of the engine off. All accessories ie: alternator, power steering pump a/c, radiator and so forth to get to the chain cover and clean out everything. That included the oil sump pan and (oil pan due to a torn gasket).

The job turned into a two week repair. With additional parts like new hoses, serpentine belt, spark plugs and such the job came to $3800.00. Well worth it, running stronger than ever.

The mechanic that did the work has been around for 20 years and never saw so much debris lying about and not have serious troubles.

I am one very lucky guy.

emerydc8 · #9 01-02-2011, 06:44 PM

Thanks for the update. Hopefully, you are good for another 236,000 miles.

EuroRash · #10 09-06-2013, 03:55 PM

Quote:

Originally Posted by umpqua101

My 1993 400e has a leaking water pump. The Mercedes dealer quoted $1,843 to replace the pump, one hose and the belt. This sounds way out of wack. They say 800 for parts and 900 for labor. The rest is tax.

My second question is; how long will a leaking water pump survive? Or will it self destruct in a short time. Right now I drive about 24 miles without overheating, park for 8 hours and then fill the reservoir with half a quart of water. Repeat. This has been for the last week.

LoL I just ran across this post.
I only paid $2000 for my 93 400E (w/ASR & 150k miles). It had a salvaged title because of a very low speed fender bender to the rear bumper (hardly noticeable) and slight dent on rear qtr panel.

The thing ran very well. I had the windows tinted and installed new headlight doors. Not to long after I sold it for $4600.

I work on Mercedes also.

For $1,000 (plus parts) I R&R a customer's 93 500SL
Diagnosed and repair ABS/ASR & soft top issues
Installed struts & shocks, new brakes rotors & pads (painted calipers)
and removed tint from signal lenses (painted by PO)

I wouldn't charge anymore than $150 for a water pump R&R