My STR6 convertible is completly stock with just over 54k miles.
I've noticed the following. Every once in a while, the car will surge for a fraction of a second. It seems to happen at different speeds.
I 1st noticed this on the drive home from Minnesota to Mass.. At 1st I thought it was happening only on choppy roads and my foot was not steady on the pedal.
Ths last line pretty much describes the feeling when it happens.
I've read the threads on the intercooler pump and thought...maybe what I was experiencing was the supercharger suddenly kicking in rather than the total lack of power (the common sympton).
Looking forward to input or troubleshooting questions.
Steve
FiftyThree033
SSB SRT6 Roadster

 

I think you're on the right track with the intercooler pump, especially if it's still the original pump. To get 54k miles on the OEM Bosch is surprising; you've beaten the odds already.

Try putting in a Johnson CM30 and see if the problem goes away. Here is where I bought mine from.....

Auto Performance Engineering - Johnson CM30P7-1

 

It doesn't sound like the pump to me. From what I'm getting out of it the car surges, but it still works fine after right, you can still drive the same?

If so I think it is normal. I like to drive with the autostick and I've noticed that there is a spot in first gear, somewhere around 3000rpm, that if I am driving along nice and easy but don't shift before I get there the car will get a sudden boost of power and jerk pretty hard. I think it is like you said, the supercharger kicks on. I've only found it in the one spot, and you have to hit it just right to make it do it, but it definitely will. But I also believe it is normal.

That is all assuming that your car is working fine afterward. If you get a sudden jerk and then you can't get the car to accelerate at all, the pump probably went out.

 

Good tip. I'll have to check for power afterwards next time. Anyway, I've got a Johnson pump on the way. From what i've read, it is way overdue.
I've got the complete records for the car from day one and there is no I/C pump in the history.

 

I have experienced this as well. I also think it is the SC kicking in.

 

Yep....winding out in first gear while autosticking..I remember getting the jerking and thought WTF. Couldnt figure it out to save my life.

 

My car has that symptom as well...and maybe it is the supercharger...But if it is, then something's not right because that bad boy should come in around 1200-1400 rpm and only go off if you let off the gas and are coasting for 30 sec. or more...According to Woody's video.

I've got a pump ordered too and we'll see if it fixes this.-Rusty

 

I replaced the IC pump with a Johnson a while back and so far no sign of the "surge".

 

If you turn off traction control then you shouldn't get the surge or jerk. Try it both ways.

 

Just found this issue (again) today. I remember having it on my old SRT-6 too. I'm going to check out shutting the traction control off to see if thats works....if it does...would that be considered normal for the traction control to do that? Would seem like it to me......but.....

 

So far it hasn't happened since replacing the bad intercoller pump.

 

THe more I read about the infamous pump, the more I think I should just throw the Johnson at my 35K mile car or wait for the surging/power loss or...

 

if you do a search on mbworld on the c32 section theres more than a few threads on the infamous "jerk". it seems the 2002 tcu has an issue. the fix was replacing the tcu with a 2003 moodel and it fixed it. may be the answer or not but good reading nonetheless!

 

I think it may be a DBW throttle issue.

 

As much as these "Forums" are helpful, don't get caught up in the paranoia. The weak points of cars when discussed on "forums" always rise to the top and are repeatedly gone over.
Enjoy your car. Use the info found in these threads to help if you know there is a problem....then throw time and money at it.
My .02 cents.........
Steve

 

yes sir...it's just info.....surging could be a lot of things...throttle, crank shaft position sensor, IC pump sensor, IC pump.....and list goes on with all the sensors the car has....but, when the pump goes you will know it, and it won't leave you stranded. In fact, my sensor was bad, but got a pump out of it anyway....I don't fix what isn't broken....but, nothing wrong with preventive maintenance either...

 

these cars seem to blow out the gaskets under the intake manifolds, ,,mine did it twice and both times it was the gaskets,,,rough idle(sometimes) surg,most of the time after running at 70 to 80 then exit and stop at a red light ,,that is when it is the worse, so change your gaskets and you will lose the surge ans rough idle,, jim

 

I had the same thing, with 35k miles. I had a stored fault code for the high pressure pump? That seemed to fix it though.

 

Hey Steve,

Any sign of the "surge" after replacing the I/C pump?

 

Good thing this thread came up. I've got the surge as well. When the engine is cold at 3,000 rpms in first or second I'll get it like clockwork. I'll be replacing the pump soon but I asked this question before and some people suggested it could be a boost leak.