[Dr. Claw]

The waterpump just went out on my 96 S600 with 105k miles. Not bad. Fortunately for me I was a 1/2 block from the house. I'm looking up parts and I need to replace everything and have found all but the tensioner pully. My questions are:

1) Are the pullys for the idler and tensioner the same?

2) When replacing the thermostat, do I have to replace the housing too?

3) Do you reccommend replacing the belt tensioner mechanism too?

Thank you for your input.

 

[The andrew]

The waterpump just went out on my 96 S600 with 105k miles. Not bad. Fortunately for me I was a 1/2 block from the house. I'm looking up parts and I need to replace everything and have found all but the tensioner pully. My questions are:

1) Are the pullys for the idler and tensioner the same?

2) When replacing the thermostat, do I have to replace the housing too?

3) Do you reccommend replacing the belt tensioner mechanism too?

Thank you for your input.

Idler and tensioner pulley may be the same size but the bolt and bearing set may be different. On your V12 the thermostat is part of the housing, o rings should be included with the new one.
The belt tensioners are tough, the spring last a long time. Sometimes however the pulley is not included, when you slacken the belt to proceed with repair use good judgement of the condition of the spring. I don't doubt however it is in perfect working order. Did an alternator on a S420 with 246k and the tensioner was original and still very very strong. Good luck!

 

[Merc600sec]

1...No different sizes different mountings
2 not unless you have significant pitting and surface deterioration..
3 Yes because if you dont it will come back and bite you..

Question.. what makes you think it is the water pump that has failed ?

Brett is the guy to ask for guidance and help on this..

 

[Dr. Claw]

I checked the tensioner spring and it's strong as an ox. But who sells the tensioner pullys other than the dealers? I couldn't find them on RockAuto, Bimmerspecialists, or RMEuropean.

Merc600sec, to answer your question, my car was making a funny noise from the waterpump area, and the dealer checked it and said that wp was gona eventually need to be replaced. Also when I checked under the hood you could see some belt debris on the water pump pully.

 

[Merc600sec]

then thats a belt replacement first.. not a pump... the idler pully and the tensioner pully and the water pump you can check when you have the belt off...

 

[Dr. Claw]

then thats a belt replacement first.. not a pump... the idler pully and the tensioner pully and the water pump you can check when you have the belt off...

My S600 took off the belt it's self. I tried turning the water pump pully and I couldn't get it to turn.

 

[Brett San Diego]

I had the same thing happen at about the same distance from home. We were lucky. Have you come across this, yet?

V12 Uber Alles, Water Pump and Thermostat Replacement in a W140 Mercedes Benz, article by Brett Allison

I think the tensioner pulley is a dealership only item. I didn't replace my tensioner, just the pulley. I think the thermostat is integral to the housing. I didn't study it enough to see if the thermostat could be removed easily. Just replace the whole thing and be done with it.

Brett

 

[Dr. Claw]

I had the same thing happen at about the same distance from home. We were lucky. Have you come across this, yet?

V12 Uber Alles, Water Pump and Thermostat Replacement in a W140 Mercedes Benz, article by Brett Allison

I think the tensioner pulley is a dealership only item. I didn't replace my tensioner, just the pulley. I think the thermostat is integral to the housing. I didn't study it enough to see if the thermostat could be removed easily. Just replace the whole thing and be done with it.

Brett

Thanks for the info. The pully spins fine but I'm gone replace it anyways this spring before I take the S600 on a road trip.

 

[Dr. Claw]

First of all I gota say, Merc600sec..... it was the water pump that went!

Here are the pics om my old and new water pump. The defective one it the $300+ Laso pump. My new one is a A! cardone which had the factory part number and the Mercedes star on it. Plus build and material quality in my opinion. The job took 6 hours to compete. I'm just glad I have my S600 back.

 

[Dr. Claw]

The other thing is that I had to fight to get the fan and water pump pully off the stupid Laso pump, but they fit like a glove on the A1 Cardone.

Laso just roped my money out of my wallet. F%@k em!

 

[Merc600sec]

that one from the bottom makes me feel really bad about how dirty my pump is and the rest of it as well almost makes me want to change mine.. but not quite yet.. good work so any other problems?

 

[Shane10010]

Wow, the old one was a bit of a mess.
Were you able to recover all the bits or are there still bits circulating in the system?

 

[Dr. Claw]

I got all the pieces, nothing inside the block. I just never seen that before. Now that is over I'm gona give my S600 a good detail and take it somewhere to get the engine steam cleaned.

 

[Merc600sec]

Ah no dont do that you will kill it...Clean by hand not by steam...