This issue with these E55s under repeated hard acceleration runs and having the ECU disable the supercharger is starting to irritate me now.

I've wrapped and heat treated just about everything I can think of, and still, after 4 or 5 full throttle acceleration runs (with no coasting in between) my ECU shuts off my supercharger and the car feels like its a 2cyl geo metro. This has been happening on and off for a while now. Each time I think I've fixed it by treating something only for it to happen again.

I have a theory about what is going on but I need some input from everyone.

I would like to ask that if you have had your ECU disable your supercharger on you could you please reply to this post and list what mods you have or if you are stock. I would like to get a sampling of who has had this happen and what modifications they have so I can test my theory.

Once I have received some responses I will share what my thoughts were...

I would appreciate it if you could help me out with this. Thank you.

 

Is your temp still more than 100c? Mine runs way cooler (85c) and have never had this happen no matter how bad I abuse it. Could it have to do with your thermostat? Just a thought.

 

I have had k1 thru k4 mod,and is experiencing it,even with an upgraded i/c pump.The i/c pump has helped a great deal.
The mods have nothing to do with it,i experienced it when the car was bone stock.
I thought i read it some place a few days ago that the i/c pump can be rewired direct,tohelp with the i/c excessive heat.

 

I've had it happen several times. Stock 06, but just last weekend I wrapped the air intakes.

 

One of the weirdest things about the E55. Happened to me once before mods....but not since, and I've been in a few situations were I was running her at high r's (on and off) for a minute or 2. You would think for sure I would have had shut off, but nope.

We'll see this summer....gets hot here and I wonder if I will have it then.

We'll see.

 

I've done everything I can think of.. My engine temp is at 85C steady now. Tonight I borrowed the use of a friend's lift, and we finished re-wiring my Johnston pump so that it turns on with the accessory key position and stays running for as long as the engine is running. I thought for sure this would have solved the problem..

On my way home from doing this work, and also wanting to get my new ECU program to learn, I did a few highway blasts in 3rd gear.. I repeated it 4 times. On the fifth try, my supercharger clutch wouldn't engage.

I dont think it can be the thermostat because my car runs at a good temp. I truly am baffled at this point...

I am hoping by the responses I get I will be able to confirm my current theory..

 

Happened to me. Stock car, stock IC system, but the crummy Bosch pump had a chewed up impeller. Only 25k miles.

 

I'm stock and it happens after about 4-5 hard pulls with no break inbetween...very very annoying!~!

 

Hasn't happened to the E yet, but the problem has occured on the SL55 twice after repeated WOT runs. First time it happened i was like WTF i thought i blew a whole in the block or something, but then i figured that the car shut off the supercharger. Now i know this is what was happening for sure, and i agree its annoying. No major mods.

 

Bone stock. It has happened to me on occasion. Once after a series of stoplight to stoplight runs, once after accelerating hard after sitting in stop and go traffic for a good 20 mins, and, a couple of times after WOT freeway/highway runs.

 

Happened to me once during the summer months after 5 or 6 runs at the 1/4 mile. During the winter months (in So. Cal.) made 8 to 10 passes at the 1/4 mile and didn't have a problem. Hasn't happened since.
Mods = Evosport I & II

 

What is your current theory?

 

Victor:

Have you been able to measure your IAT when it the S/C failed to engage?

Am I missing something? Because it you are between +5 and +10 of ambient IAT, you shouldn't be experiencing this (correct?).

Mark.

 

The intercooling system on these AMG cars is wholly inadequate. Even with moderate upgrades the car is not designed for prolonged boost. Running all the engine mods such as pulleys and ecu's only manages to make the situation wore and worse.

I can make my stock E55 or SL55 shut down due to IAT's at will. It just takes some pretty hard driving. If I had pulleys it would take only a few romps on the freeway to shut things down.

In a warm climate like the middle east these cars last but 20 seconds when you try to drive quickly before the kompressor is cut due to high IAT’s. It’s a story you hear time and time again. The system is good enough for more places and people but when you have the car cut out you want to pull your hair out.

Have had a serious issue with this with SMGC32's car we use for road racing. These blower cars do not do well with modded motors and road racing. The extended WOT makes the car shut down and you need to do serious work to make things stay in check. The C32 with a chip and ECU only works for 4-6 laps before the blower shuts down for a lap of IAT cooling. Picture the car cutting the blower right as you are setting the EVO you chased down for the last 6 laps up for a pass on the front straight. Its the most annoying thing possible.

I have done some serious testing and data logging (using Nology OBDII scanning and logging software) in my E SL and in the C32 I use at the track (SMGC32's car) and IAT's make the blower cut like clockwork. 199 degrees and pop cuts the blower until it cools below 155 degrees. DME lets the 2002 C32's go to 255 but 2003 and 2004 cut the blower at 199 degrees. WAY TO HOT.

It is fixable though.

PM me -- I have some thoughts would like to share.

 

I have read many posts in the past on this topic but I'm sorry to report that with my K2 & I/C pump upgrade I've never experienced the infamous Kompressor shut down. I also have the -10 degree celsius option done at my dealer. Don't know if that has anything to do with it but it's working like a charm. Whether on the street or on the dyno, things have been consistant.

 

Vrus, never happened to me yet, although i normally pushed the car hard early in the morning or late at night....

 

Tony,

What's the -10 degree celsius option?

SAC

 

I have K1 with Evo Headers. I run my car pretty hard every time I drive it and this has never happened to me. If I'm at the track the car will lose a couple of tenths but the sc is still engaging. Good luck with the problem.

 

First.. Thanks to everyone for replying!! Much appreciated.

My theory was this:

The stock car has 2 weaknesses that should be addressed.

1) The stock pump is garbage and should be replaced with the higher flowing Johnston pump.
2) The supercharger's intercooler cooling circuit should be separated from the car's cooling system circuit so that the heat in the engine coolant doesnt affect the supercharger's system.

Saying that.. I was thinking that maybe once the circuits are separated there just isn't enough volume of fluid to keep up with the heat being generated. Once the circuits are separated, with the new overflow tank that I have as part of the Evosport upgrade, the system only holds 4 liters of fluid. I was thinking that maybe a bigger overflow system needs to be put in place to increase the capacity of the system and therefor increase its efficiency?? Not sure if I am correct on this or not...

I just did another 35min data logging session this morning. I am going to have a look at it and see what is there.. I will share more info once I have had time to go through the data.

As for the IAT.. Yes.. I was recording +5 to +10 over ambient for IAT when I put the Evosport cooling upgrade on the car. Between the time I first got it and now, I've had 1 pump fail and had to replace it. Since I replaced the pump and put the Evans Coolant in the intercooler circuit, I've been getting the supercharger cut.

I am not sure if I have air in the intercooler circuit thus making the pump & heat exchanger less efficient.. Any way to test for air being trapped in the system?? Could a small air leak in a hose cause a problem? Or maybe the Evans coolant is the problem.. I will have to change that in the summer and switch to water/water wetter and see what happens.


Have you done repeated WOT blasts on the highway with no cooldown/coasting inbetween? For me it happens the 4th or 5th time I've done 3rd to 5th gear 100km/h to 200km/h WOT blasts. I slow down and repeat.. By the 4th time it cuts.

As for -10C mode.. I am familiar with it.. It originated from me. Glad it worked out for you. Besides, that mod is only good to keep engine temp down. That worked miracles for me because my engine temp was always 100C and now with that change I made it is 85C so that part is under control.

One of the things I was researching/trying to build was a fan controller circuit so I could turn on the engine fans sooner than the ECU. Doing this research and speaking with some "techies" I discovered that with Star Diagnostics there is a option where you can set the FAN START TEMP. It is a range of 0 to -10. -10 being 10C lower than the ECU's default setting.

When you change this option the fan comes on sooner and goes at a much faster speed.

At the track its tough to see this because you have a cooldown period from the time you finish the 1/4mile to the time to stage again. I only see this happening when I am on the highway and REPEATEDLY run from 100km/h up to whatever speed I decide to slow down at ..

On the dyno it has never happened and on the street doing WOT blasts it has never happened.

 

What is this??? Thanks!

 

Read my last post just above yours.. I explain it there..

 

Here is the original thread:

https://mbworld.org/forums/w211-amg/123809-another-tip-heat-management.html

Some people were having difficulty finding a service tech that was familiar with how to make the -10 degree adjustment.

 

Your data logging should indicate if there's a problem with system capacity. You should see IAT rise incrementally with each succeeding WOT blast.

I'm not familiar with the Evo system, but in most cooling systems, the overflow tank is not included in the cooling flow. It's just there to contain overflow liquid, which gets sucked back in when it cools. If you want more cooling capacity, you're gonna need a bigger system, not a bigger overflow tank.

The Evans coolant (which is a propylene glycol-based solution) is more effective at cooling higher-temperature systems where localized boiling is a concern (this is also known as nucleate boiling, where the combustion chamber walls cause the coolant that is in direct contact with them to boil and generate vapor - the Evans coolant will condense the vapor sooner compared to water). For lower-temperature applications, it is not as effective as water, since its specific heat capacity is much less (I don't recall the exact figure, but I believe it's at least 20% less). You'd be better off using it as the engine coolant and using water/wetter for the IC (when freezing is not an issue).

Since you've established a baseline with logging, it should be fairly easy to swap out the Evans fluid and re-test with water. Your IAT and SC clutch will indicate if it's better.

 

Grumpy666,

Thanks! I always appreciate and welcome your input.

The problem did start happening right after I replaced the failed Johnston pump and put the Evans coolant in.. Maybe that is the issue then.. I will drain the system since Spring is around the corner and replace with Water/Water Wetter..

Thanks for clearing up the overflow tank thought.. I was thinking that the overflow is used to store the coolant and if I put a bigger container in I would have more volume available for the system to use. I will scratch that thought off the list..

Do you think it is worthwhile to replace the engine's coolant with the Evans Race coolant? My engine temp never goes above 86C.. Even with the 4 or 5 WOT blasts on the highway, the highest temp was 86C.

 

Hi VRUS,

I have a stock 04' E55, and I have experienced the "cut-out" more than a half a dozen times, usually when I am doind more than 3 or 4 accelaration runs (in a row). It hasn;t happened as of late (it being winter an all), but when the outside temp is over 70, it can happen after just a few hard runs (freeway.highway).

Allen