gkstar

Title says it all, I guess. When RPMs reach over 5000, IAT quickly climbs to over 200F and next time I press the gas - no S/C. Note that the S/C dos not cut off in the middle of the acceleration, but after I let the pedal off for a few seconds and then floor it again.

Any idea, aside form the faulty I/C pump???

Going back to the dealer tomorrow afternoon.

wawy

I would have to say it's the intercooler pump again. Maybe it was not connected right or the "new" one was faulty or refurbished?

430

How long ago was the pump changed?

If it was just changed I would check the fuse. They may have failed to replace it.

gkstar

The pump was replaced twice during the past year. First time it was the pump for sure and problem was rectified with a new pump. This time the conditions under which the S/C cuts off are slightly different, but they changed the pump again yesterday as being the usual suspect. The new pump was tested for sure, apparently they can turn pump on and off with their tool to test (I know the mechanic - a great guy). They bled the air out of the system too.

IAT is still hovering around 175F with normal (well slightly spirited ) driving in cool weather.

As for the differences in behavior between the two instances:

• Previous problem - When the pump was out the previous time, S/C would cut off when you step on the gas just after cruising on the highway at 80mph. S/C cut off was more frequent, often causing jerks as it goes on and off.

• This time - Now it would cut off only after hard acceleration when RPMs reach 5000+ RPMs, though it does not go off during the acceleration, no matter how hard it is. It cuts off after that, as I let the gas off, wait for speed to decrease say by 20mph, and then apply full throttle. It seems as if the S/C is engaged until the moment I start pressing the gas and then after a split second it goes off.

Looks like computer clearly tries to protect the engine for some reason (likely the high IAT). When that happens, CarChip throttle reading is at about 50%, even though I go full throttle on the pedal (with switch depressed).

evanswan

I am having the same problem and its intermitent but now happening more frequently. Fletcher jones replaced the pump a little over a year ago when I complained of the super charger not kicking in. around 80 mph when the car has been running about 20 minutes or more and it shuts s/c off. Today, shut off just going 0-40 sprints most likely due to high rpm heat. going to take it to Vadim@GMGRacing in Santa Ana

splinter

Ensure that the intercooler fluid circuit has been bled of all of its residual air. Because the core is at the highest point of the system, an air lock is a naturally occurring phenomenon.

MB’s procedure necessitates activating the pump while plugging (“pinching off”) the intercooler core fluid return line. Upon proper evacuation of the system, the I/C vent hose (yellow) that normally connects to the anti-freeze/anti-corrosion fluid reservoir is to then be observed discharging only a steady stream of fluid.

CynCarvin32

Splinter is correct so that could be the issue.

Also check the relay associated with the pump. The relay can be faulty causing the pump to not work. When I had a C32 it went through 4 pumps and an intercooler core.

If you cant get is fixed with the relay - pump or the bleeding solution there is always the chance that your intercooler in the V of the motor has started leaking. If this happens the core can be caked in dried coolant and it prevents the air from traveling through the fins and this means your charge air is never cooled. I had this happen.

To check to the leaking core pull the intake manifold off and peek down into the runners. IF you see dried up coolant caked everywhere that is a bad sign. This means coolant is clogging everything up and you have seriously restriced air flow and a clogged intercooler core.

The coolant will collect once the car is shut off and the system is still pressurized. Once it sits for a bit it dries very hard. When it leads under use the car just burns the coolant up in the combustion chamber.

edtv82

what kind of pumps are you guys using? ... i just put on my Johnson pump b/c i was having similar issues with my S/C but... im thinking if you're having to replace even an OEM pump twice a year... i would check the relay b/c your pump might be staying on way too long not shutting off b/c the pumps are good for so many hours...

gkstar

Thanks for the feedback, I have an appointment next week. I had the mechanic come with me yesterday for a drive and he clearly saw that the issues is beyond the I/C pump. They tell me the air is out of the system but checking for core leaks seems like a next logical step. If it is an intermittent relay or harness issue, then it may be harder to troubleshoot.

dkflipse

Is the Johnson pump 100% plug and play?? No special wire splicing need to be done?

m444

Pull off the air intake plenum (surge tanks) between the intercooler and the heads, you will see coolant in the passages, if the intercooler is leaking.

If the intake air is getting too hot, the issue should be intercooler, pump or the blower has excessive friction. The engine coolant temp should be about 90C.

Also, it would be nice if you could check monitor the battery voltage, when the supercharger cuts out, if the voltage gets too low at the supercharger clutch or relay it will disengage. Also, the ECU will drop it out at 9V.

If the IAT sensor were bad or had a bad connection, it may affect temp ECU intake air temp readings and cause early drop out.

How are your air filters? A collapsed intake hose can cause some issues also (lots of drag for the blower).

Eurocharged Rick

no, it is not 100% plug and play...you do have to splice the wires and i drilled a new hole in the mounting bracket to secure the pump...and a couple of hose clamps...

1qikctr

I need a johnsons pump. Dammm Bosh products SUCKS.

gkstar

Thanks for all responses. My car was at the dealer for 3 days and they could not figure out what the problem might be, car is going in for service within a week again for the same thing.

Don, good points. I will monitor the Battery next time I plug in my CarChip.

I changes the filters last spring with original air filters, same part number, made in Germany. Timing of the problem roughly fits, though I checked the filter box and all seems original, bought from a reputable o-line place. So, these filter should not make it harder for the S/C to suck air in. Checked the whole visible air intake path and all looks good. I am now convinced to try the Green filters and see if IAT is lower with them as they have less air resistance.

The interesting thing is that S/C does not cut off during high RPM acceleration but right after that. Say I floor it at 60 and it goes to 120 mph with no problem. Then I let the speed dye down to say 70 and if I floor it at that point, no S/C at all. It seems as if the engine is trying to protect it self, high IAT being the main suspect. I will make sure they check the sensors as well.

Julio77270

Did you solve your issues?

c32kompressor

have the dealer leak test the intercooler. they are known to leak. if your mechanically inclined, remove the two intake plenums and look inside them. if you see a greenish brown sludge, you have a leaky intercooler. the sc will cut off after a pull until it sees IAT's lower. I have a feeling it cuts off only after a pull because IAT's jump because the intercooler is low on fluid. once you slow down IAT's can drop and kick the blower back on. if your IC pump is bad, you would notice the sc kick off much more frequently. also your old ic pump could have gone bad due to lack of lubrication. (coolant)
a leaky intercooler is a very common problem with 32's

viper04

Nice to see you have it worked out. Das_it16 is a pretty good guy.