I ordered a Johnson CM30 to replace my flaky Bosch unit the other evening. Tonight I was flipping through Needswings web site and came upon their opinion that the high flow of the Johnson pump blows up the I/C of the SRT-6 cars.

Of course now I'm afraid to put this thing in, so I wanted to get feedback from guys running this pump to see how many have ended up with leaky I/C's after going this route.

Is this more an issue of deferred maintenance with respect to people not changing coolant? I've always been fanatical about keeping fluids clean and up-to-date. My thoughts are that anything made of metal will corrode and weaken if rust forms.

What say the Oracles of the SRT-6?

Cheers!

 

This is a very good question and concern. I wondered the same thing when I read that on the NW's site.
I don't recall where; but Waldig (Woody) had his explanation somewhere here about the failures. Something about the expansion/contraction co-efficient of two different metals. Block and IC? I'm not sure. Hopefully there aren't that many that this has actually happened to. I don't know if this has anything to do with it, but some of our cars sat for 2 years or more before being sold to an end user. The factory coolant has a rust inhibitor in it, so that's probably not a viable cause. Just throwing that out there for debate.

 

OP- I have thought this before and if I recall have seen a few people with failing IC's had the bigger pump, including one of my fathers cars. Me personally im just going to replace the stock one with another stock one, if it means I have to replace my pump a few times throughout the life of the car and possibly saving my IC then so be it.

 

intercoolers have been failing for yrs before the cm-30 was tried. remember the engine was built in 2002 before the xfire was an idea. the fix was another bosch pump. imo separeting the system from a high pressure system to a low pressure system takes the worry out. i run a cm30 with zero issues

 

Three plus years with the Johnson installed without an issue - but I also installed the larger LET HE and completely isolated the cooling systems at the same time....

 

the inner coolers fail....nothing related to pumps...some last a long time, some don't...just hope you got a good one...install the pump....

 

Sorry for the dumb question, but not owning a SRT, I am curious. Does the stock system run on engine collant? If so I assume it is cooled by the radiator before going to the pump and into the heat exchanger? What is the difference between how a hight pressure vs. low pressure system in plumbed?

 

the coolant resovoir has 4 chambers and the i/c and the radiator both flow thru them. by closing off the i/c from the tank it becomes a low pressure system and the radiator remains a high pressure system. and yes the i/c uses the engine coolant

 

This is what the OP referenced; that when Rob @ Needswings hears about an IC leak, he suspects the addition of a higher pressure aftermarket pump, and that's why he only sells the Bosch. (which is less money BTW). That said; hopefully Rob can add to the discussion.

 

it this idea of a bigger pump causing i/c failures then all the c32 cars with the meziere pump which is a HUGE pump would have i/c blowing up every were. and it hasnt happened. just my .02 2 yrs on my old 32 and the same pump is on my new 32 without a single failure

 

I don't own an SRT either, but I don't believe the aftermarket pumps have higher pressure, I don't think they are positive displacement pumps. They probably have a higher flow rate, which could cause problems for coolers that are borderline. James

 

Coolant Pumps can only generate a few PSI of pressure. If your intercooler is isolated from the engine there is no real pressure on the IC and the pump is not going to cause an issue. THe stock system went from zero to like 15 PSIG every time you started and warmed the motor up. That stretching is like doing an accordian in and out causing metallic stress on the thin tubing and leading to cracks and leaks.

IMHO separate the cooling loops and dont worry about the pump capacity unless it is a fuel pump that can generate like 40 psig. My utube videos showed the testing and pressure / flow of stock and better pumps and I remember only like 3 or 4 psi capacity. Woody

 

I have been using the CM30 pump for almost 3 years also with no issues.... I did separate my system similar to BrianBrave's and have the LET HE.....

 

I ordered the separator kit at the same time I ordered the CM30, so I guess I subconsciously was thinking along the right lines. I did think it was odd and inefficient to utilize a high-pressure cooling system that carries higher temperatures to begin with such as the engine's coolant system.

I'm glad that I ordered the CM30 now that I am reading feedback from users who have run the pump without issues, especially after separating the two circuits.

Cheers!

 

I too have been running the Johnson with no problems , Needswings Seperator Kit also.

 

Wading in... I actually just purchased a Johnson CM30 but have decided not to install it and purchase a OEM bosch unit instead. I won't be changing anything else to my engine, prefer to leave it stock, so to me it is not worth even the chance that IC fails.

Will probably be selling the Johnson CM30 if anyone is interested. It is my fault for not doing enough reading on the issue before buying. I was aware of the potential problem at the time of purchase, but the more reading I do the less I want to take the risk.

 

If I am understanding Waldig correctly. The separator kit is a good idea regardless of the pump used,and the Johnson should be safe with the kit.

 

What would u want for the johnson pump ?

 

Feel free to PM me.

 

Regardless of which pump you use if you don't separate your cooling systems you are still stressing your IC. The pressure from the engine coolijng system is also pressurizing your IC system causing the stress that Woody mentioned. When I pull the cap off of my IC cooling system there is NO pressure.

SEPARATE YOUR COOLING SYSTEMS! <- yes I'm yelling!