They go out fast and with no indication of failure. I paid a bunch of money to have a mechanic check the car out and he didn't' say anything about it. There is no warning message or light for it. It just silently quits after a very few years and lets the fluid that is supposed to cool the air entering the engine (heated by the supercharger) sit stagnant. A friend has a $75 gizmo that plugs into the car's interface (that the dealer connects its computer to) (above your left knee) and reads out a ton of info. He had to do this on his CL55 so he suspected mine might have the same problem due to it's age. So the day after I got it home from the "find everything you can" guy, we plugged it in, found the readout in the menu and checked the temp at idle, before any acceleration. It was pretty hot, I don't remember that reading, but he tells me it is supposed to maintain about 15 degrees F above ambient, and it was a above that. So I pull out on the street and did a little acceleration run and it busted 204 degrees F. But the key part, is that it stayed there. It wasn't circulating through the heat exchanger, so it wasn't cooling the fluid at all. Another way to tell is to feel the pump. You can tell if it is running if you have the touch. We switched it out (easy fix) one bolt, two clamps and two wires (get self soldering wire joiner gizmos-heat with a lighter). You can get the Bosch part on the net for about $115. http://www.siliconeintakes.com/produ...0042431b970117

It is located under the front passenger side of the car. After you remove the underside shroud it is very obvious. It looks like a tiny starter motor or a coil except for the two hoses coming off of it.

After it was fixed, even though the ambient was 100F, it kept the coolant temp low and brought it right down after a run. It creeps me out that it was near boiling all that time without me even knowing it. Having the intake air so hot probably did a number of the engine management computer responses too, not to mention killing horsepower with hot air.

 

Good to hear it's been swapped out. Bought mine with a busted pump too back then. I went with a CM30 from Johnson and now have a complex setup with a CM90.

 

interesting. i spoke to rentech and was told about this problem. they have a pump that supposedly has 100% more flow than stock, but the cost is $1395. any info on this, or alternative pumps.
thanks

 

100% more flow than stock, but for that price talk to Shardul and prepare for a tank in your trunk. Then you ripping tar for sure. That will cool things down dramatically.

 

My politically incorrect thought is that Mercedes designed it to have very adequate cooling given where they thought they would probably be selling a LOT of these (oil countries i.e. deserts). I know how you guys like to hot rod though and cool air is a pretty cheap and safe way to boost HP.

 

you bought the original IC pump? I thought the it was poorly designed so a lot of members recommended the Johnson CM30 pumps...

 

thanks for the info. can you tell me where to get the johnson cm30 pump.
thanks, harv

 

type it out in google, you should have no problem finding it

 

http://www.johnson-pump.com/jpmarine...ion/index.html

I don't see a spec on the Bosch pump for the size of the nipple/tubing. All three smaller Johnson's have 20MM tubes, is that the same as stock?

 

is the johnson cm30 plug and play, or are modifications required?
thanks

 

I'm pretty sure it's a direct replacement for the weaker Bosch pump...but I'll wait for someone who has the mod to chime in luls

 

I believe the Johnson is plug and play in terms of the hose, but requires the power connection to be spliced (that part won't plug in). You need the little splice connectors from RadioShack.

 

What saintz said, someone posted a guide with pics on another forum..

http://www.benzworld.org/forums/w215...-pictures.html


(hope its ok to link that here, btw)

 

that's for V12, not V8Kompressor

 

Same pump and location.

 

when i checked the link it appeared that the bosch pump had a vent line and the cm 30 did not. is this correct and is the vent important?

 

The Johnson pump is not plug and play. The OD of the pump is smaller and you would have to modify your bracket. Not only that, they are magnetic driven and SUCK!!

Blew two out from reading all these johnson lovers post, before I did my own test. I have taken them apart and posted the info in the past. They suck! Once I saw the design, I knew I had been had! The Bosch HD from siliconboost is a good pump and most of the non magnetic drives are too but require some fit mods.

 

I love definitive answers.

P.S. I know this guy, and he knows his stuff.

 

So what pump should one get? Part number? Link to where to buy? Also good question with the vent. Where do you put the hose on the new pumps?

R.K.

 

Can you provide a link for your earlier post on this topic ? I want to learn more. I was looking at Johnson pump in the past too but was suspicious about the quality considering they go for less than $150.
On the other hand looking at RennTech pump for $3.4k not sure I want to spend that much unless we do a group buy and get some nice discount !

http://www.vividracing.com/catalog/r...-p-118218.html

 

Didn't I post the link to the Bosch pump in the original post?

 

http://www.siliconeintakes.com/produ...0042431b970117

 

need opinion. i have a 2004 cl600 with a renntech chip and everything else is stock. i use the car as a daily driver and stomp on it occassionally. i'm confused. what would be the best, most reliable pump i can get as close to plug and play as possible?
thanks

 

http://www.siliconeintakes.com/produ...0042431b970117

 

Your Links aren't working...

R.K.