I took off the ETM on my 2002 T6 three weeks ago, cleaned it, put it back on and saw no major differences (it accelerated noticeably smoother, but other than that there was nothing wrong with it in the first place). Now yesterday, as I was in a full throttle merge onto the freeway from about 30mph it heaved a few times, gave me the flashing check engine light (on the right side of the dash) and now it won't run properly.

I took it off yesterday (again) sprayed it with carb cleaner (again) and wiped it out (still clean). No difference. Here is where I think I went wrong: the first time I took off the ETM I pushed in the butterfly valve and held it so I could get the rim and edges clean. I saw a YouTube video of this and it bested my better judgement to push the valve in. At some point during the process I noticed the valve was no longer as tight as it was, or it was somehow out of position at rest. On inspection I noticed it had a little more give than I would like it to and the gap at rest seemed a little larger than it should be. Also, the slightest amount of force will move it a few millimeters.

There are two things I think might be causing my problem. Either, when pushing the valve in I pulled something in the electric motor or stretched a spring and I need a new one. Or, I somehow dislodged the valve from the correct gear position at idle and I can still fix it. The electronic part consists of an electric motor, a transfer gear, and a notched, spring loaded piece connected to the valve.

Yesterday, I tried to adjust the spring loaded piece with the transfer gear so that the valve would sit more closed at resting position (what I assume is idle). It seemed to make the car run more consistently, but still having major idling issues. Is there anything I can do here, or did I just learn an expensive lesson?

 

Look for a vacuum hose or air plenum tube which may have fallen off.

I had a bad experience with spray carb cleaners because they often can get into the electronics and damage something. I never spray them towards anything which is electronic such as the throttle position motors and sensors. I always spray onto a cloth and use the cloth to wipe the throttle.

 

IMO it is near impossible to get fluids inside an untampered ETM as they are very well sealed.

Use OBD2 reader to pull some codes first, then you will know for sure.

 

Don't think fluid in the electronics is the cause. I did open the case, but didn't spray inside and left it as clean as I found it. Had the codes read with p0300, p0303 and p0306. These are multiple cylinder misfire, cylinder 3 misfire and cylinder 6 misfire.

 

the misfire issue-
Switch the coils from cyl 3 and 6 to 2 other cylinders and reset the codes. If the problem reoccurs in the cylinders you put the questionable coils in, then replace the coils.
If the problem reoccurs with cylinders 3 or 6, replace the spark plugs in those (or all) cylinders.

In the case of a american car, I sprayed inside the throttle body with carb cleaner and it went through the clearance between the throttle shaft and the end bearing into the throttle position sensor. It failed instantly.

 

I did as you suggested, switched coils 3 and 6 with 2 and 4. The problem now reads in cylinders 2 and 4. Coils. Oh well, could be worse. I'll replace those two for now. I'm going to go with two Bosch coils from eeuroparts.com. I can also tell that the plugs are bad going on worse, but I've read a lot of controversy whether you can use aftermarket replacements. Is it necessary to pay double for the genuine Volvo parts? If not, will Bosch be sufficient there too?

 

The throttle appears to be a non-issue at this point. I would recommend doing the cleaning, but would caution pushing the valve in more than you have to. It seems likely that spraying directly into the body is a bad idea as well, when you could spray into a rag and wipe.

 

I do not remember which brand plugs I put in but I know it was not Volvo and worked fine.
Suggest you stick with a major well known brand and I personally would use a conventional plug which you set the gap on as opposed to one with mulitple electrodes.
Bosch shopuld be fine.
Sounds like you found the coil problem so good luck.

 

Bosch coils can be obtained from most auto parts stores for about $50-60. I had 3 go bad within several weeks of each other. Now I have the other 3 in my garage waiting for future failures. My car had about 250K miles at the time.

 

Anyone know if running the car down a few cylinders can cause permanent damage to the exhaust system or drive train? I'm thinking the catalytic converter and exhaust system has to be getting doused with unused gasoline, not to mention the extra stress on the remaining cylinders. Unfortunately I don't have alternate transportation, and I've put a few hundred miles on the car during the past few weeks. Mostly highway, but a good share of stop and go traffic too. Is there anything else I should be looking out for?

 

Yes, it can cause issues with the cat as well as excess bore wear due to the fuel washing down the oil. Simple fix though....disconnected the injector for the corresponding cylinders until you have a full set of strong coils in there.