03 CTS Throttle Body

mickeydog · #1 (**permalink**) 03-11-08, 04:45 PM

Hello,I was having problems with a real rough idle but after searching the forum I come across cleaning the throttle body to clear up the rough idle which I did and it ran perfect but after awhile it would idle rough again so I cleaned the throttle body again which was gunked up again,ran perfect again.My question is why does the throttle body keep getting gunked up?Is there a better procedure for cleaning it,do I have to remove the TB entirely from the intake and do a more complete cleaning?I used 3M Throttle Plate cleaner with a clean toothbrush.Thanks again for this forum you all are great

dkozloski · #2 (**permalink**) 03-11-08, 04:53 PM

Throttle bodies can get gunky from overoiled aftermarket air cleaners or heavy breathing PCV systems.

mickeydog · #3 (**permalink**) 03-11-08, 05:00 PM

Hello,I have a stock AC-Delco air cleaner and I really do not think from the previous owner they installed an after-market air cleaner,it was a stock AC-Delco also installed when I purchased the car.Now the other thing you suggested I have no clue,how would I go about fixing the problem.Thanks

odysseus · #4 (**permalink**) 03-11-08, 08:16 PM

I just pulled my TB a few weeks ago to clean it. It's much easier to get behind the throttle plates with it off the car. Also, I found it was dirtiest in the passages that go to the vacuum lines over top of the manifold (that big black plastic stripe). It's not that hard to pull it, and it has two large O-rings (not gaskets) so it's easy to reinstall. I had the intake hoses removed, the electrical connector disconnected, the four bolts holding the TB to the manifold off, cleaned, and back on the car in 30 minutes.

Other than the vacuum passages, my TB was remarkably clean in the throttle bores, even with an oiled cotton filter on for the past 80K miles.

What made a huge difference in idle quality was replacing the Bosch spark plugs with Denso Iridiums. Expensive, but they even change the tone (deeper) of the engine growl at WOT.

That was a two day job! Figuring out how to get my hands to some hidden bolts and pulling everything covering the coil packs was a bear. The actual changing of plugs took all of about 10 minutes. I've got 94K miles on mine.

mickeydog · #5 (**permalink**) 03-11-08, 08:39 PM

Thanks alot for the information I will let you know how it goes,Thanks again