robertjm

Hi all,

I'm pretty sure I know the answer. But, figured I would ask anyways.

Is this a sign the water pump has gone bad? First started hearing this noise last night coming home from work, when I'd be stopped for traffic lights. Today I popped the hood and was greeted with the sound you hear on the video below. What particularly caught my eye was the way the front part seems to be wobbling, and you can see it seem like it's popping in and out in the video.

There was a definite leak underneath the car as well, just from running the engine to take this video.

Other than the pump, what might be the issue? Also, when searching videos on YouTube, I could only find videos for ML350 models. Is replacement the same procedure on that engine as on the bigger one? I know the fan assembly is different.

Maj. Dundee

Here are the procedures and part #s.

Place new pump on a piece of cardboard and trace it. Then punch holes in every bolt hole. Then when removing bolts they should be placed in the same hole as there are many different sizes and lengths.

robertjm

Thanks so much!

robertjm

Just to double check. I need the water pump with only two ports, not the three port model?

Maj. Dundee

Erroneous info.

robertjm

You did. I just wanted to double check by posting those photos. :-)

robertjm

I ordered a water pump, idler pulley, drive belt and belt tensioner, per suggestions both in this thread and elsewhere. But, as I'm watching YouTube videos I realized I didn't even think about the Water Pump pulley.

Is there any reason to think that would be damaged too, or should I be pretty safe to refuse the one that's in the car already?

Maj. Dundee

That's difficult question to answer since you are the only one seeing it.

robertjm

Fair enough. Sounds like it's not as definitive answer as with the tensioner and idler pulley seem to be. Most people advocated changing those out of hand.

One thing I found interesting is that there seemed to be only two options for the Water Pump pulley, at multiple vendors I checked. Either Uro or Mecedes-Benze Genuine; and the difference is about $30 vs. about $150. That's staggering!

Maj. Dundee

In other words, does it look damaged?

Maj. Dundee

What is you full vin # ?

robertjm

4JGAB75E03A412702

robertjm

All right. Started in on the project about Noon today.

Had a chore taking out that fan, and along the way it slipped out of my hands and "might" have punctured the radiator. There's a small "hook" on the left side of the fan as you're facing the engine compartment, and when it flipped, that hook impacted the back of the radiator. Obviously, won't know until I get the thing under pressure. But, I was definitely flustered. My brother-in-law says maybe I only bent one of the fins. I was going to take a photo. But, forgot to.

I stopped at the point where I was trying to remove the tensioner pulley. I pulled the two E-12 bolts from the pulley. But, it seems like it's stuck to the engine block good. Any hints of wisdom on how to get that unstuck? Or is there a third thing holding it that none of the videos mention? I stuck a screw driver behind part of it to see if it just needed a little back pressure. But, nothing doing.

Also, any hints on keeping that front pulley still on the water pump so I can remove those four front T-30 bolts? I tried physically holding the pulley. But, couldn't get a good enough grip to get the thing going. I really hate the thought of buying a new one. But, that's the next option if I can't remove the current one. There doesn't seem to be much in the way of damage.

Maj. Dundee

As per you vin#, here is your part #.

robertjm

Interesting because the one that is in the car, most certainly, only has two ports and there's no oil cooler installed. Wonder if the previous owner, or the used car lot I bought it from, frankenwrenched it to keep the car rolling? But, that's hard to swallow because I met the guy who bought the car new, and he seemed like really cared for his car. Plus, they'd have to replace the water pump and the oil filter holder. Though it might also explain the oil that's on the engine. :-(

Maj. Dundee

Compare your pump to this one.

robertjm

That's what mine looks like. Only the two bottom hoses. The first diagram you posted above shows it as ...1401, which is what had me tripping on the 2 vs 3 hose issue earlier. The replacement I bought was an Italian company starting with an S (name escapes), who supposedly also builds the pumps for Graf now.

As a side question, there's a ton of oil in that section of the car. Basically underneath the oil filter area. Any suggestion on likely culprits where that might be coming from? I'd just assume fix it now with the parts out, if it's not something major like an engine gasket. And how would you clean up the oil? If it's not effecting the operation I can just leave it be. But, it looks like hell, and it's got to be coming from something over there.

Maj. Dundee

There is a ton of oil where?

robertjm

Directly below the oil filter section, and the nook between where the tensioner pulley was and whatever that pulley is the right. Also, the underside is oily in general.

robertjm

After looking at the situation in better light today, what I thought was the bottom bolt on the tensioner was actually the left bolt on the pulley to the immediate right of the tensioner. Once I figured that out it was easy to get the second bolt, and the part literally fell out of the vehicle.

The water pump pulley is off! We ended up breaking the bolts with the pair of a vise grips and leverage from a screwdriver because the 5mm hex heads were getting munged up when we tried it with a wrench. I'll buy new bolts at this point. Hopefully, either a standard bolt head, or an E-torx version, which is easier to get a hold of when it comes time to either torque in upon installation, or to remove it laster on.

robertjm

Man, oh man! It's been a long week. Between running to get parts and unexpected calls from the boss, I'm finally getting around to install the new water pump and the get the car back together. It's amazing how much you miss having a car when you don't have one.

Did run into a question though. There are two gaskets that come with the pump I bought. A small rubber one, which resembles the same as I pulled off the vehicle with the old pump. Then there's a flat gasket. In one video the guy used the latter, and even said he wasn't sure what the first one was used for. Then there was a great assembly guide on Benzworld by a user named Merzatt, where he specifically says to use the flat gasket.

Are BOTH used?

Maj. Dundee

A photo of the oil leak would have helped, but I think you are referring to the Oil Pressure Port that is leaking.

Is this the part that is leaking?

robertjm

Honestly, the stuff was all over that area, as well as below it and on the undercarriage. I did have a problem with my power steering reservoir before, which I replaced, so some of the gunk might've been dirt mixed with power steering fluid. But, I'm sure a portion of it was motor oil as well. A couple of day's ago I cleaned it all up as best as I could, though not perfect. But, it'll be obvious if a leak springs again.

Based upon other posts where people mention this little guy being a leaker, I went ahead and bought a new cover and the rectangular gasket that fits behind it so I'll R&R is along with the other stuff just in case. The cover didn't come with the circular part so will reuse that. The guy at the parts shop I bought it at said to replace the crush washer at the same time.

Maj. Dundee

You will have to order these small parts to stop the leak. Dealer only about $20.

robertjm

So i can just reuse the expansion plug? Drat!!

i have to order a new gasket today anyways so I’ll do that at the same time.

thanks for helping.