I’m from Holland and own a srt6. Bought it new and have driven more than 300.000 km with it. I love the car.
At 150k km the supercharger did, unfortunately sometimes, not kick in when putting your foot down at 40m/hr. No relationship with hot or cold engine. It appeared to be the crankshaft sensor. At 300k km same thing. I replaced crankshaft and camshaft and temperature sensors. Checked the supercharger elektromagnetic initiator. Found that the intercooler (below the supercharger) was toast and replaced it. Replaced the coil. Ignition is not the problem. All injectors work and all temperature readings are ok.

Does anybody have an idea in what is the problem here? I know the distribution chain has slack because the crank and camshaft show an angle difference, that could be the problem? To replace this I need to take the engine out which I would rather not 😂.

I want to take the car to at least 500.000 km 😄 and will never give up on my baby.

Thanks and kind regards,

Han

 

Han

The first thing I'd check is that the intercooler circulation pump is in good condition and is running. If it is then don't worry about the rest of my post, but if it isn't then read on. The IC pump is protected by a 10A fuse and is switched by a relay in the Pulse Module. The relay in the Pulse Module is controlled by the ECU.
I don't think the problem would be with your ECU, but if it doesn't see any current flowing to the Pulse Module then it wont turn on the Supercharger Clutch. So I guess what I'm saying is, check the IC pump fuse and if that is OK then I'd check the output of the Pulse Module (or just plug in another Pulse Module). Your car has very high mileage and the relay in the Pulse Module could be worn out.

If it is the Pulse Module and you're having trouble getting a replacement, then you could also use a normal 12V Relay to do the job. The ECU would control the relay by providing a ground to the relay coil.

 

O.P., Most of us would agree with the above post. Can you explain what you mean by your C.A.C.(charge air cooler/ intercooler) "was toast"? It sprung a leak? If so, it may have occurred because the circulation pump for your intercooler was toast. Hot/Cold, Hot/Cold, expansion,contraction, etc. Did you R.&R. your C.A.C. before checking out the pump? Also, you mentioned that you changed the coil(singular?). We have (6) coils; but you knew that, right?

 

When I said that the C.A.C. was toast I meant it must have been leak because the entrance and piping were all a bunch of muddy stuff. So I replaced it. Thanks for the tip: I'll check the circulationpump. Somebody already told me to also check the fuse and the output of the Pulse Module. I would think that if this is the problem would not occur only sometimes (like in 50% of the time)?

Regards .... Han

 

The intermittent clutch engagement,like when the intake air gets too hot, is exactly what happens when the circulation pump needs replacement. The intake air sensor prevents the SC clutch from engaging. It cools down, then works, then gets too hot, etc.,etc. Search the forum for this issue; it is well documented. Good luck with it.

 

We did the modification such that the pump is always running. Air intake temperature is always between 29-31 degrees celsius. Intercooler has been replaced.
And …. The problem of intermittent SC still exists 🥺.

Is it possible that the clutch electromagnet is worn out after 300.000 km? If so, van I buy another one?
Is it possible that slack on the distribution chain is the problem?

Many thanks for any help.
Han

 

You didn't mention if you checked the operation, and or replaced the ic circulation pump or not.

 

I did not change the circulation pump. But if it is not working properly then the intake temperature would not be 30 degrees always, or not?
How can you check the operation otherwise from knowing it is running?

Han

 

My guess is that you have (2) problems. It's impossible that your intake temp. is "30 degrees always"(I'll assume celsius/ 86deg. fahrenheit), unless your temp. sensor or monitoring device has failed. How to know whether the coolant is circulating is a good question. Some of us here have, in addition to coolant isolation, installed either an inline fill canister that you can actually see the coolant movement, or a supercooler(see one @ NeedsWings.com)that have a cap to open up and see the fill. This isn't proof positive either, because if the pump is intermittent, or just not pumping adequate volume, well, you get the idea. I would just change the pump like hundreds of us have had to do. You can find that @ NeedsWings also.

 

Ok, I’ll replace the pump. On the temperature: obviously I meant it is always around 30 degrees Celsius, like between 28 and 32. To me that means the pump is working?

I’ll be back.

Han

 

How are you monitoring your coolant temp.? What are you reading it with? IMHO, when you removed and replaced your charge air intercooler, the pump should have been checked and or replaced at that time also. Where did you get that CAC replacement? Good luck; let us know if the new pump fixes your issue.

 

So by chance have you had your supercharger pulley off at all during this time? I only ask as I’ve changed my SC pulley bearing twice just as preventative maintenance. Most videos I’ve watched of the SC pulley coming off is for the M113K which always comes straight forward and smooth without much fuss at all. Now for my experience with the SRT6 -M112K and the factory SC pulley isn’t as straightforward a pull and there is not as much space as the M113K to remove it. So both times I’ve tried and tried to pull straight out but it won’t go. I’ve for lack of a better word had to walk it off the shaft. The first time when I had changed it I thought everything went well it went on smooth and everything looked copacetic. Then it started having the problems you describe which is the classic original ICP failure which is Bosch last 3 numbers part# 003. So I took that as the problem and ordered the newer Bosch #010 IC pump. While I waited for the part I combed through the forum and after reading up my symptoms weren’t exactly as the failing pump but that of an improper SC pulley and magnetic clutch gap. I took the belt off and was looking at the gap and on top it looked fine but when looking at the SC pulley from the side the bottom was way off and was causing the problem. Basically the SC pulley wasn’t set properly and the gap at certain points would be out of reach for the magnetic clutches range. You’d think with the amount of force that clutch can pull it would have lined the SC pulley up or the belt would’ve done similar. So I took a rubber mallet literally hit it once and I saw as I heard it pop down into place. Belt back on and everything was back to working order. I was extremely lucky that I didn’t snap or stretch out the dog leg springs from the SC pulley. Just an FYI I still changed to the newer pump. Sorry for the novel just wanted to give some more insight into this

 

Its correct to replace te pump. The early failures were the vanes on the impeller inside the pump. The pump would run giving the impression it was circulating fluid but only be making noise. Thats one reason you'll read on this forum to be sure to replace it with the Bosch 010 pump that superseded the original. I hope it solves your problem. I believe it will.

Les

 

I had similar problem and changed ic pump and it continued having supercharger cut out. I found a post on forum about wiring a connection in fuses to have the pump always on when ignition is on. This took care of problem with no cost. May wear out the pump earlier is the only downside.

 

I replaced the is circulation pump with the 010 number. The problem seems to be solved 😄 although I have the feeling that at 40 km/hr the SC does not kick in as intensively as at 70km/hr but maybe this is the case because it does not shift back?

Thanks for all the help and information.

Han

 

Glad you got your issue sorted. I'll take a stab at answering your above question here. Once your SC kicks in typically around approx.1300-1500 rpm(depends on load*), it remains engaged until you slow down to nearly stopped(approx.5mph), or shift to neutral. When you step down on the pedal at 70km/hr as you say, the intensity you're experiencing is not the SC kicking in(because it's already engaged), but is your engine getting into the powerband(probably 3rd gear)and is the power/torque that we all enjoy. When you have a well modified SRT6, the power comes on like a freight train in 3rd gear. Forum member "Woody" has a video and explanation of the SC engagement here on the forum if you want to search for it.
* Can be as high as 2900 rpm, but that is a whole other discussion.

 

Dear dinasrt,

I can not find the video, is there a link?

Also, I still think the SC is not as lively as it used to be, sometimes it fails at low speed. Did you ever experience that the magnetic clutch was worn out? Could this be overhauled? Maybe at a shop for alternators?

Many thanks,

Han

 

It is near impossible to diagnose over the internet for most issues. One thing that comes to mind for me is for you to wire inline an L.E.D. light to your magnetic clutch SC circuit. I have done this, and velcro'd the light under the hood lip on the drivers side so that I can actually see when the SC engages and disengages while driving. It lives there full time. You can then see precisely when it does its thing. I used a nice little green light for GO! The magnetic clutch is either engaged or not engaged; it typically doesn't slip. But check your spacing between it. Any slip that occurs is usually the Serpentine belt slipping from pulley, causing less boost. Another way to monitor is to have a boost gauge. It lets you know the psig at all times, and can let you know if you have an intake leak or not. But you need to know what the boost is with no leaks before you can see whether you've acquired a new leak. You're giving us a seat of the pants feeling that you're having less power. And you're telling us the power is low at "low speeds". That seems normal, but it could be many things though. Belt slip occurs when pushing it real hard, not at low speeds. Regarding video; keep searching. But it basically tells you less than I've already shared with you now.

 

I replaced the IC pump and wired it such that it always works. I replaced the intercooler which will have been leaking for years. I. Replaced the distribution chain. And stil quit often it feals like the supercharger does not kick in. I had the supercharger checked by a specialised company, they say that it (inc. The clutch) is OK. I found the gearbox was slipping (no wonder after 300k kilometers) and replaced it. And … the problem still exists. Maybe it is the SC or maybe the injection? I read somewhere that sometimes the relais box is the problem and can cause all kind of problems. The computer does not complain about anything by the way!

Does anybody know:
the OEM number for the relais box?
know whether the box from the SLK 3.2 AMG is the same?

well …I only spent only one year until now and built myself a better car in the mean time. If I can solve this then I’m done 😅

 

Hi,

Your IC pump may now be permanently on, but if the ECU doesn't see a load on it's ground for the IC pump, then it won't engage the SC. You wont get any DTC's, the SC just wont work. The ECU monitors the output and only engages the SC when it sees that the pump is on. Make sure that the ECU is still wired normally to the pulse module and that the relay inside the pulse module is still working (it's coil is ok). If it isn't then use the output of the ECU to provide the ground for a dummy relay. Make sure any relay you use has a diode across it's coil so that it doesn't hurt the ECU.