dirtyhogan

Replaced BOSCH with Johnson CM30 pump, replaced IAT sensor, replaced fuses, bled coolant, I have no clue where the relay is in front of the SAM.
and my SC still cuts out.

I removed the pannel in the wheel well and can feel the pump pumping when the car is running. Is there a chance this pump is not pumping at full potential becuase of a relay issue?

Stock pulley, stock HE...

I'm lost for where to go next! Should I hook up an OBD2 and check intake temps? What are normal readings on these cars?

What else could be the problem?

SC runs when I first start the car, pulls until it gets mildly hot then cuts out, if I cruise without throttle it cuts back in briefly then cuts back out which leads me to believe it's either a problem with my computers ability to properly read IAT's or my sytem is not cooling properly.

Any tests or suggestions to narrow down this issue?

Is there anything else that could be causing this problem?

Beaker

The issue you described second last sentence is 100% what I have... but I haven't put in a CM30 yet (have ordered one)..

I know when I hooked up to the computer to check errors with my mechanic the other day he said there were some IAT warnings and so I'm going to replace the sensors .. but you seem to have already done that so I'm not help!

Hope you find the answer's you're looking for..

gt4awd

If the new pump is running the relay should be good. So that takes the pump, relay, IAT sensor, fuses, and air in line out of the question. Not sure what's left to check after that, but hopefully someone will know. Quick question. What is the average temperature in your area at this time?

dirtyhogan

30 to 40f, I"m lost for ideas... Only thing I can think of is some fault from the IAT to the ECU...

gt4awd

One thing that comes to mind is a problem with the electromagnetic clutch on the supercharger... You can verify this by monitoring the IAT, and if the supercharger is disengaged below 195F you have a problem with the clutch

dirtyhogan

Hmm... Sounds good, two wires going to the clutch wonder in there could be a short there... Got any test ideas?

TemjinX2

maybe check for air bubbles in the coolant lines?

dirtyhogan

checked that.. bled the lines quite a few times... Maybe I've got a leaky ic and thats creating air in the system and adding heat.

dirtyhogan

I'm going to make my reservoir and see if it's losing coolant.

TemjinX2

i had a leaky intercooler and i didn't have my sc cut out. The coolant from my resevoir would get lower and i could see white steam coming from the bottom of the engine when i drive for a while and let it sit.

TemjinX2

i would get a obd II reader and see if it throws any codes. Preferably if you know anyone with a star machine it'll list the reasons why it cuts out.

dirtyhogan

No lights are on... MB have soft codes that don't throw CEL's?

TemjinX2

you can have codes without throwing a cel. With star you can see all the mercedes codes and history. Usually a cheap obdii reader can still see most of the codes.

dirtyhogan

sounds good... I'll check that tomorrow, I'll also check IAT's. Thanks again!

W203Ramos

I can't recall what thread it was but, it was a loose connection on the sc clutch. which caused the sc to disengage despite iat's being normal...if I find the thread I'll post back GL

OBD II SCANNER http://shop.ebay.com/i.html?_kw=obd&...rcedes&_ckw=II saw on ebay hope this helps.

loudandheard

I'm about to do all the things that you have done. I'm worried I'm going to have the same out come. I did recently change my supercharger bearing, but I think I was having the problem before that. So I'm not sure if the pulley could be affecting the clutch.

dirtyhogan

Ramos any luck finding that link?

Cheers!