...and I was quite shocked by how clean it looked. I used a cleaning solution - poured it in the intake side a number of times and what came out was dirty, but far less so than I expected.

The boots collected quite a bit of oil in their recesses. All in all a very easy job that made no apparent difference in performance...perhaps the rest of the intake tract is dirty

I didn't have time to get to the throttle-body...

 

Thats quite a large number of miles! What kind of stuff have you fixed/replaced?

 

Oh God, don't ask him that!

Meb, did you wash acetone through it?

 

I sprayed about 3/4 of a small can of throttle body cleaner through the IC after 40,000 miles and only got a little bit of stuff out. It was mostly just the cleaner a little oil mixed in it. Even before I sprayed there was only a thin film that probably could have just been wiped out but I decided to run the cleaner through in case any had made its way deeper into the IC that I could see from the end tanks. Then I installed a catch can to hopefully catch anymore oil vapor before it gets back in the IC

 

Lotsa winshields

Nik

 

It also helps to spay water through the IC fins (and rad and a/c condensor) to get the years and miles of dust that accumulates there. Airflow through the fins are important for heat transfer.