Dirty body pic

[JPNinPA]

How do throttle bodies get so gummed up?
Bought a low mileage (20k) patriot for a family member. Drove it for the past few years so now it has ~60k on it. I take pristine care of this one. 3500 oil changes. New filter every time. Run some Techron every oil change…
It started randomly bucking at low rpm.
So i did some homework.
Some people cleaned the TB and some replaced them. Others changed plugs. All stating it is now fixed.

So how bad can the TB be?

I couldn’t get an image of the inside but that black tar ring was through the entire TB.
Guess i have to check the pcv to see its not stuck?? Engine runs great. IDK.





Never look down on anyone unless you are helping them up - Jesse Jackson

 

[Gennybro]

That's the results of running cheap gas . Impurities in the cheaper gas is what you are seeing. I have a moped with 33,000 miles on it and the engine is still strong. That's because I only ran high test in it.

 

[JPNinPA]

Most gas has detergents in them now. High test or high octane denotes burn time more than cleanliness.
So what brand is cleaner?

But not to argue a TB doesn’t see gas directly, it should be air. The gas gets injected in the intake just before the valve on non direct inject engines. Pressure in the intake should be low(vacuum) with gasses flowing toward the intake valves. What does get sucked in besides vac pneumatic switch air is crank case gas pressure and emissions from the charcoal canister.
Not sure when you let off the gas and engine brake/coast if the pressure changes or gas flow throws back at the throttle plate.
Its not so much that it got dirty but how dirty i was amazed by.


Never look down on anyone unless you are helping them up - Jesse Jackson

 

[JPNinPA]

Edit.
New engines loose rings allow less friction and more carbon in oil and elsewhere. And when you shut off the engine the hot gas fumes rise to reach the TB and cool.
This jeep does lots of short trips.

Never look down on anyone unless you are helping them up - Jesse Jackson