Throttle body cleaning

[Mntnbkr]

Has anyone cleaned their throttle body? (no jokes please...) Is it easy access on the 5 (have not looked yet)?

I did this a while back in my VW and it was waaaay too easy (just be sure to not cut up your hands and knuckles - things are machined very sharp in there - at least on my VW) - it did wonders for smoothness of idle and acceleration. Removed lots of carbon/gunk around the butterfly that must have been affecting the airflow or valve actuation/compensation...

Thanks.

 

[jimp]

sure, there's some high mileage 5's around that would warrant it, check out the Mz3 maintanence forums, as the 5 & 3 share the same engine & tranny combo's. Looking in a 5's engine bay is idential to looking in a 3's engine bay, as I own a 3 & a 5.

 

[Mntnbkr]

Thanks.
I only have 50K on the odometer...have you done it yet, and for only 50K is it worth it? Would like to smooth the idle if possible.

 

[d-machine]

ive done it on my 3 a few times.. it does make a big difference just get the throttle body cleaner from the auto parts store and dont spray too much, you can use an old tooth brush and some type of towel (i used a cloth diaper cause ive got a bunch just laying around and they dont have lint and crap) just open and close the throttle body by hand while you clean it to get both sides. when you start it up it will give a little hesitation after that it will be good to go

 

[Mntnbkr]

Good to hear - thanks.
Do you disconnect the battery while doing the cleaning to force an ECU reboot/recalibration of fuel/air mixture and how the butterfly valve sits? My understanding (at least on my other car) is that carbon deposits force the butterfly valve to open differently (or more) and once clean it needs to reset to base.

 

[jimp]

don't forget to clean the maf as well, but use the maf cleaner not the TB cleaner and BE CAREFUL with the maf

 

[flcruising]

I see no reason to unkook the battery, even if you remove it to clean it. Just don't obviously turn ON the ignition (if you remove it - that is). The ECU is always 'learning' so whether it's from base or a newly cleaned TB, it shouldn't matter either way.

 

[Wishmaster]

Probably a good idea to disconnect the battery, especially if you clean the MAF as well, it should help the ECU take advantage of the cleaner conditions.

 

[d-machine]

yeah it is a good idea to disconnect the battery just so you dont mess anything up

 

[Robotazky]

Be sure and open the butterfly valve all the way and clean the back side, especially the bottom of the back side. Easiest way to do it is hold it open to one side with your hand, spray TB cleaner on a rag, wrap the rag around a screwdriver or something, and rub the crud off the back. Don't use the tip of the screwdriver and scratch up the valve plate. Cleaning the top of the back side is easiest, but does the least for improvement. You want to clean where it seats at the bottom, front and back and including the end of the plate where it seats, and also the TB itself where it seats. The rest of the valve should be pretty clean. If it's not, you definitely needed to clean it.

If the 5 has a idle air hole that goes around the butterfly valve, hold a rag behind the rear opening (inside the TB with the valve open) and spray into the front hole. Let it spray through. Try to blow the excess out before you start it.

 

[Mntnbkr]

Be sure and open the butterfly valve all the way and clean the back side, especially the bottom of the back side. Easiest way to do it is hold it open to one side with your hand, spray TB cleaner on a rag, wrap the rag around a screwdriver or something, and rub the crud off the back. Don't use the tip of the screwdriver and scratch up the valve plate. Cleaning the top of the back side is easiest, but does the least for improvement. You want to clean where it seats at the bottom, front and back and including the end of the plate where it seats, and also the TB itself where it seats. The rest of the valve should be pretty clean. If it's not, you definitely needed to clean it.

If the 5 has a idle air hole that goes around the butterfly valve, hold a rag behind the rear opening (inside the TB with the valve open) and spray into the front hole. Let it spray through. Try to blow the excess out before you start it.

Good info on cleaning - thanks. Q-tips seemed to work well on my VW and they will never scratch...just don't let go of the Q-tip.

Does anyone know if there is a separate idle air hole in the 5 throttle body or is that function part of the main valve/body???

 

[nopsled]

Hi Mntnbkr.. most likely by now you'd done this a few times. Just curious about results.. thxs in advance