Just picked up an '03 SL55 with 45k miles. After reviewing the forum, it seems like I should replace the IC pump/charge air circulation pump sooner rather than later. I've searched and read about replacing the crappy oem pump with a Johnson CM30 or an updated Bosch unit where the "part number ends with 10." Is one pump better than the other? If the Bosch is better, does anyone know the full part number. Any recommended sites to buy parts from, other than the dealer? I'm sure these questions have been many times, but the search function revealed numerous dead ends. Thanks in advance!

with a stock cooling system people have had good results with the updated bosch pump
Bosch 0392022010

this

the new updated pumps are stout.

Thank you VERY much! Found it for $117 online using the part number. I also called the dealer, since I'd like to develop a relationship with them, and their price is $378?? I tried to give them the part number, but they said they could not look it up that way. I had to give him my VIN and then the part I needed. I guess this way they know 100% if the part will work for my vehicle. I definitely do not mind paying more to a brick and mortar business, but not at a markup of 100%+.

Interesting as I was at the dealer service shop last week and spoke with the tech about the IC pump. His comment to me was that they rarely see them go bad on the 55 cars, and if/when it does, you'll get a CEL code thrown. His point was that the car will tell you when it breaks, so if it aint broke, don't fix it.

Thoughts?

Replace dealer.

You can throw an "intake charge temp too high" code and know that something is wrong, but You really need to beat on it to log th code. Most of them don't throw any code- just run underpowered. Btw, all non updated Pumps fail.

I just replaced mine, 03 sl55 22k miles with johnson pump wired it to run full time ,my supercharger would shut down after 3 qtr mile passes with no light or codes now car ran 2 tenths faster then it was

Got the new IC pump a few weeks ago. Now that I've got the time to put it on, I do have a question for those that have done this themselves. After the new pump is put on, what is the process to bleed air from the circuit? Other than that, this looks like it'll be a simple job.

Do a search. You need to make a bleeding contraption or use a radiator vacuum setup (like a snap-on).