Exotic-metal55

One stock I/C pump out but not sure how long it had been bad. 2 johnson pumps (Cm30) in the last two months already.. Any ideas on what could be causing this?

Can it be heat, wiring, trash or air in the lines? Getting shell shocked now..

Ausmbtech

When you "gone bad" do you mean that the supercharger turns off when hot or when they are removed from the vehilce they dont work when you bench test them?

Yacht Master

Exotic, how did you wire the pumps?
Most terminate the stock wiring and tap a "on with ignition" power source from the fuse box (cant remember the terminal).
I think the CM 30 is a magnetic drive so trash or air can be ruled out.
I have had Johnson pumps run for years 24/7/365/ in marine applications, like Ausmbtech said, bench test is in order.
Question to the board, One last thing I would like to know, the pump is controlled by the ECU. Dose the power come directly from the ECU or is it from a relay, triggered by the ECU?

Jakpro1

I am not seeing larger heat exchanger with these mods

If this is still the setup you are running, especially with the ASP, you will have supercharger shutoff occasionally.

Gotta get the LET exchanger or Code 3 exchanger on ASAP.

I installed the Code 3 and LOVE IT!!

Exotic-metal55

I use ATAP to tell that it is not working. Everything was fine a couple weeks ago and then I checked IAT`s today.. Just normal very slow driving and they are 160 deg! Engine coolant was only 178-185 on a warm motor.

When the pump works, I run 25-30 over ambient and that should have been 125 ish today..

Wiring? I just cut off the stock connector and and put positive to positive wire and negative to negative. Yes, it still is PC controlled but seems to run most the time that engine is at normal temp.. I can use a tester and it shows power to pump but pump is not running.

ChicagoX

Go into the rear SAM, check fuse #4.

I've seen poor wiring cause too much draw, blowing the fuse.

Exotic-metal55

I just used a light tester to check wires after my drive to work and I have power to the red wire on the pump but pump will not run.. I tested the wire with car running and hot. ATAP showed IAT at 144 with only 64 ambient and no recovery if I punch it. The pump is not working. Same problem as the last cm30 4 weeks ago. Pump had power , IAT `s hot and then after the pump change all was fine until now.

To be honest, I am baffled by this. It is only two wires and two little hoses. Two CM30 pumps already?? I returned the first pump to try and get warranty but now they will not respond and seem to avoid all contact.

Exotic-metal55

More info. I noticed after the first CM30 failure last month that small black particles came out in the fuid near the pump. When I picked them up, the disolved like they wewre part of a seal or rubber part.. After the second pump install, I flushed fluid and started over fresh.

I am not sure if many people know when their pump fails.. Not many test this or have data recorders to test running parameters.

I noticed that the specs on the CM30 Johnson pump, rate the fliud temp for only 212F.. Not that we get there with a good punmp but could come close at times. Could temps be failing these pumps? Melting seals or impeller?

I sure liked all the hype on this CM30 pump but going with the Bosch until I /we can figure this out.


Since I have power to the red wires on both my failed CM30`s , I am guessing one of 3 circumstances can exsist right now..

1) Killed by fluid temp ?
2) Sold TWO defective pumps?
3) My factory wiring is killing the pump for some reason after a few weeks?

Any thoughts?

Yacht Master

Exotic-metal55

Have you bench tested the pumps?
The Johnson pump is a magnetic drive (shaft not connected to impeller) and has no seal, this is a safety feature to save the motor in the event if foreign objects lodged in pump or clog / restriction in the plumbed circuit. So the motor can run and not pump water in certain conditions.
So it is important to bench test, the first test is simple just hook it up to 12V if it runs next test requires some hose and water. If when electrified it dose not run, return it. (same for #2 pump). Check the pump number too you could have been sold a 24 volt model.

Other questions,
Is your IC system split from engine?
Jakpro brings up a good point, do you have stock heat exchanger or aftermarket? (bigger heat exchanger is good idea with ASP pulley
Do you have any pics of how the pump is plumbed?

Jakpro1

Hard to tell but anyway you are running them dry even for a few secs?

You clamping the hoses before you do the pump or draining them dry..then changing. I use hose crimp clamps from Slapa (napa) so fluid loss is minimum.

Sorry for the rookie question. You sound like a guy that has some knowledge of turning a wrench or 2.

Exotic-metal55

I have the stock heat exchanger and never have S/C shut off. Since I have a CL, I have two heat exchangers already. I do plan to add a larger H/E but like doing one mod at a time before adding more band aids. When the pump works, I run 25-30 over ambient and after a run have about a 25 seconds until full recovery. These runs are all done in 90-98 deg. weather.

I/C is not split. That is a whole other debate.

I did not clamp hoses off on the install. About 1/2 gallon of fluid is drained into clean jug and then re-filled.. The pump has worked well for several weeks each time , until it fails.

I really like the design of a magnetic drive but baffled by this.. Hard to see how one small air pocket in a line could cause failure several weeks later but who knows? I have 3 air bleed lines built into my overflow tank, so it takes air out quickly.

I appreciate all the response and I do need help on this one.. Rather spend
my wrench time on larger mods than this..

TopGun32

every time you switch your pumps... you loose small amounts of water..

make sure you don't have an air bubble.

Run your heater while driving on the freeway or street for about 5 minutes and let the system completely circulate.

If your wiring is fine and the pump does not turn on.. obviously it can be the pump, but remember that the pump does not become until water reaches a certain temp.


I had a high IAT issue 3 months ago when switching to the new C3P HE. Everything seem to be running fine but IAT's were crazy high.

Turned out to be an air pocket.

AMGTestDriverNJ

Wow, this is good stuff. I wish I knew as much as you guys did about how to figure out what the hell is wrong with half the stuff that goes wrong with my CL. How can you tell if the pump is not operating properly? Does is show up on the SDS? I always accuse my car of being slower than it should, but maybe I'm just used to it? I have had the S/C cut out in the past but the IC pump has been replaced since then. Either way, this is good stuff to read and its too bad there aren't more of you guys in the other parts of the boards that I frequent. I'll be sure to check back over here w/ u 211 AMG guys on a more regular basis. Thanks

PerisanGodFatha

whats the code 3 exchanger? is that the heat exchanger? how much is that setup?

Jakpro1

Yeah just the larger radiator for better cooling. It also replaces stock smaller exchanger so coolant does not have to travel all through elbows to each exchanger. Direct bolt in with no drilling required.

They are out right now but the brand new design should be avail in a few weeks.

Spearco units....SWEET!