2000SL1 Idle when cold

Hey all,

I have a 2000SL1 with 78K miles. Automatic (2nd transmission >.< ouch).

When the weather bottoms out and the temp drops the car will start and idle
at 3000RPM. Yikes! Then it will drop down to normal, but when I put it in
gear, the RPMs go back up and the car could practically drive itself (could
be why my transmission failed at 70K Miles). When I put the car back in
neutral, it revs to 2-3000RPM and back down to right under 1000. This
problem is intermittent. I've switched to synthetic oil to hopefully
protect a little from the startup revs until I fix this issue.

Anyway, I've replaced the O2 sensor & Air Cleaner. I will be replacing the
PCV this weekend.

I was reading it could also be caused by clogged injectors. Would running a
can of injector cleaner through the system be ok ? I only ask because as a
rule I don't put 'extra' junk into my oil/gas unless recommended. I'd
rather err on the side of caution.

Also, I've heard that along with PCV, the Electronic Coolant Tempurature
Sensor can be faulty and cause this. Does the ECTS go by another name ?
These folks at the parts stores aren't necessarily the brightest bulbs in
the pack.

And finally, is there anything else I can do to try and remedy the problem
myself? Your suggestions are greatly appreciated!


-Chris