Car shakes a little but when speed is kept steady.

When driving at a constant speed where the car is under any slight load the engine will randomly jump up 200 rpm and shake slightly for about a second. This happens every 30-60 seconds and only when the gas pedal is kept in a constant position and the car stays at a steady speed.

Anyone know what is going on?

The shake feels kinda like a CV problem, or a wheel out of balance. But it is unrelated to any specific speed, rpm or gear. No Check engine light.

It's been going on forever but since it started I have replaced the motor mounts, CVs, brakes, tires have been balanced, the suspension has been completely rebuilt. New VNT-17, Malone stage 3, EGR delete, new nozzles.

Out of curiosity......manual or automatic?
How many miles on car?

Will it do it when cruise control is set?

csstevej said:

Out of curiosity......manual or automatic?
How many miles on car?

Click to expand...

Automatic. The shifting was a little rough and glichy prior to the Malone tune. Now it is super smooth. It had its first tranny service a few years ago. Not that I didn't ask to have it done prior. Fix Um Haus, I think the owner was just being lazy, told me not to service it...

190k miles on it.

I haven't tried getting it to do it using cruise but I would imagine so. It doesn't do it at freeway speeds though. So I would say when the RPMs are higher than 2500 this doesn't happen.

Have you serviced/replaced vacuum lines? Checked N75 valve?
Is the vacuum bleed line attached to the airbox? There is also a

small white round check valve that could be fluttering. I deleted mine
with no ill effects.

That rpm shift is the TC lockup solenoid engaging/disengaging.
This is a precursor to transmission trouble and will likely soon set a DTC.
If you scan it now you will likely see a code. If you like or need the auto trans,
you can try doing a fluid/filter change if you haven't done it recently.
Try the 'Kerma Mod'. There's not much to lose and it could buy you a little time.
If you already have the right amount of fresh fluid in it, consider an upgraded valve
body from CoolAirVW who is a specialist in the 01M, among other things.
If you don't much care for the auto trans then start gathering the parts for the swap.

flee said:

...If you already have the right amount of fresh fluid in it, consider an upgraded valve
body from CoolAirVW who is a specialist in the 01M, among other things.
If you don't much care for the auto trans then start gathering the parts for the swap.

Click to expand...

This^^^. The symptoms you describe indicate valve body wear. At least, that is how it sounds from here. CoolAirVW has written up some excellent posts about the 01M and how to troubleshoot it. Read them all and hopefully you will be able to start answering your questions.

Good luck,

PH

Rrusse11 said:

Have you serviced/replaced vacuum lines? Checked N75 valve?
Is the vacuum bleed line attached to the airbox? There is also a

small white round check valve that could be fluttering. I deleted mine
with no ill effects.

Click to expand...

When I did my EGR delete Old poopie at fix um haus reworked a lot of my vacuum line system. I'm not sure what they did though other than the broad strokes. They took out the EGR solenoid (I think that is the N75) and put in a filtered vacuum intake (I have no idea what that was for).

Bleed line into the airbox? I'm not sure. I had the airbox out recently and there wasn't any vacuum attached to it.

There is a vaccum connection on the straight pipe that replaced the EGR valve I just plugged it up.

I will start replacing vacuum lines though that's always a good idea for a car of this age anyway.

flee said:

That rpm shift is the TC lockup solenoid engaging/disengaging.
This is a precursor to transmission trouble and will likely soon set a DTC.
If you scan it now you will likely see a code. If you like or need the auto trans,
you can try doing a fluid/filter change if you haven't done it recently.
Try the 'Kerma Mod'. There's not much to lose and it could buy you a little time.
If you already have the right amount of fresh fluid in it, consider an upgraded valve
body from CoolAirVW who is a specialist in the 01M, among other things.
If you don't much care for the auto trans then start gathering the parts for the swap.

Click to expand...

OK Thanks, This has been happening for 90k miles or so I was so happy when I got the Malone tune because it quieted this all down. I have a trany filter change and fluid replacement 2k miles ago. I'll look into it.

If you have any specific links I should look at that would be great.

OK found the write ups.

Sounds like I have to send the valve cover to Kansas to get machined. Replace all the solenoids and go to larger valves.

The Kerma Mod is to tighten that star adjustment 4 clicks.

Did I get everything?

kola8273 said:

OK found the write ups.
Sounds like I have to send the valve cover to Kansas to get machined. Replace all the solenoids and go to larger valves.
The Kerma Mod is to tighten that star adjustment 4 clicks.
Did I get everything?

Click to expand...

4 clicks isn't going to change the line pressure very much. Maybe try 8 or so to start.

flee said:

4 clicks isn't going to change the line pressure very much. Maybe try 8 or so to start.

Click to expand...

CoolAirVW has this on his website:

http://kansascitytdi.com/o1m-faq/

"Should I do the Kerma Mod?"

"I’ve driven a few cars with the Kerma mod done with the adjustment rammed all the way in, and they drove terribly! Clunking and banging on up shifts and downshifts. I’ve also read of transmissions that had this mod running hotter. This happens because the higher pressures tend to move the pressure regulator valve farther into the bore which tends to cut off torque converter charge, which is the same oil as cooler flow. But, this mod seems to be necessary on cars that have performance upgrades, but there has to be some control. I recommend 4 clicks. This raises line pressure from about 55 to about 70. Do not ram the adjustment all the way in. I can undo the mod and adjust it 4 clicks. Your car may flare on shifts after undoing the Kerma mod, until the computer relearns. Resetting adapts with VCDS may speed this process."

Good to know, I did my 01M 8 clicks and the result was barely perceptible.
If your valve body will be modified or replaced then don't bother. It will come preset.