Cleaning the Throttle Body of Mopar V6 and V8 Engines

by John Mastriano

Although John is a dealership technician with 20 years of experience, neither he nor Allpar can be responsible for the accuracy of this information or the consequences of using it. Read and act at your own risk.

Cleaning the throttle body of 3.9 V6, 5.2 (318) V8, and 5.9 (360) V8 engines

Start by removing the fresh air intake tube from the throttle body .
Disconnect the three electrical connectors (AIS motor - TPS - MAP). Read about what these sensors do.
Remove the throttle cables but leave the bracket attached to the throttle body .
Remove the vacuum line .
Remove the four 13mm attaching bolts and remove the throttle body from the engine.
With the throttle body of the engine remove the AIS motor and MAP sensor but leave the throttle position sensor attached .
Use a suitable throttle body or carburetor cleaner and spray the throttle bore and throttle plates . Use a toothbrush or rag soaked with cleaner to remove any carbon build up from the throttle body bores as well as the AIS motor housing . Also clean the AIS motor pintle .
After the throttle body is clean , dry it off with some compressed air or allow it to air dry and reassemble it .
Now disconnect the battery for a few minutes to clear the adaptive memory.

Cleaning the throttle body of 3.0 and 3.3 liter V6 engines

To start off disconnect the fresh air intake tube from the throttle body.
Now remove the throttle cables , electrical connectors , and vacuum lines .
Remove the two 13mm nuts and remove the throttle body .
Remove the AIS motor but Do Not remove the throttle position sensor .
Using some carburetor or throttle body cleaner and an old tooth brush , clean the black carbon from the throttle blade and the housing , also clean the AIS motor pintle and shaft . Blow off with compressed air or allow to air dry and hold the throttle body up to a light . You should be able to see the light coming evenly though the gap around the throttle blade .
Replace the gasket and reinstall the throttle body .
It is a good idea to disconnect the battery for a few minutes to reset the adaptive memory.

Cleaning the throttle body of 3.5 liter V6 engines*

To start off you will need to remove the fresh air intake tube from the throttle bodies (there is enough room to leave it behind the throttle bodies) .
Now remove the throttle cables, the electrical connectors and vacuum lines.
Remove the 13mm nuts and remove the passenger side throttle body first and disengage it from the linkage connecting rod .
Now remove the rod (making a note of the tension spring position) and the drivers side throttle body .
Using some carb. or throttle body cleaner and an old toothbrush , clean the black carbon from the center throttle blade and the housing . Let dry or blow off with compressed air. If you hold it up to a light you should be able to see an even amount of light through the gap around the throttle blade .
Replace both gaskets and reassemble starting with the drivers side first .
Now remove the AIS motor and clean the carbon off the pintle and its shaft.
When it is done it is a good idea to disconnect the battery for a few minutes to erase the adaptive memory.

Using a spray can

Greg Smith posted this at Neons.org. It was not written by John Mastriano!

Mopar Combustion Chamber Cleaner/Conditioner is really good for removing carbon deposits...The following directions outline the way that professional mechanics have been using the cleaner for years -- they were finally published in TSB 18-31-97 for 1996-98 Jeep 4.0 Liter misfire conditions:

Operate the vehicle until the vehicle reaches operating temperature.
Remove the air tube from the throttle body.
With the engine at an idle, spray the entire contents of Mopar Combustion Cleaner, p/n 04318001, directly into the throttle body. Allow the vehicle to load up with the cleaner to the point of almost stalling out.
Shut the engine OFF after the entire can is ingested.
With the hood closed and the vehicle parked inside the garage, allow the vehicle to soak for two to three hours. This will ensure that the engine will maintain its temperature and will allow proper solvent penetration.
Drive the vehicle on a highway/freeway that will allow the vehicle to be driven safely at the posted speed limit. Upon entering the highway/freeway, accelerate hard to the posted speed limit and maintain speed. Slow down and then perform 5 to 10 Wide Open Throttle (WOT) upshifts. Continue driving at the maximum speed limit for 1-2 miles (if conditions allow).

* Notes on the 3.5

Stuart Janda wrote: There is only 1 throttle body on my car. No 13mm nuts to remove. However there are 3 Torx size T30 screws to remove the throttle body from the engine and 1 T40 to detach the throttle body from a bracket. I didn't need to remove a rod. (This was on a recent 300M.)