• Welcome to H4O! For a reduced ad experience, please login or register with the forum.

H3 Throttle body and MAF sensor cleaning

Boerwarrior

Member
Messages
17
Location
Sacramento, CA
Throttle body and MAF sensor cleaning on 3.7l I-5 H3

It was time to change my air filter so i decided to check the Throttle body and give it a scrub down too.

I think this took me about an hour to complete. It’s not difficult at all, just take care with the MAF sensor as it is a sensitive piece of equipment.

To start, the tools i used:
10mm nut driver
Phillips screw driver

The cleaning sprays I used:
TBcleanerspray.jpg



1. Disconnect battery.


2. Disconnect plug at MAF sensor.
MAFsensorplug.jpg


3. Loosen 2 clips on the air box lid and the hose clamp on the air outlet hose between air box and resonator. I removed the hose at the resonator so that I could remove the air box lid and hose assembly that houses the MAF sensor all together.
airintakesystem.jpg




4. [FONT=&amp]With the air intake out of the way you now have access to the vortec resonator. [/FONT]Loosen and remove the 2 bolts (10mm) that hold the resonator to the valve cover and loosen the hose clamp where the short air outlet duct attaches to the TB. With the resonator loose you can swing it out of the way in order to access the 4 bolts (10mm) that hold the TB.
2.jpg



5. Disconnect the sensor plug and the vacuum hose on the throttle body.
TBsensors.jpg



6. Loosen the 4 TB bolts and remove, holding the TB as it will fall away once the last bolt is taken out.
4tbbolts.jpg



7. With the TB removed I took it to the work bench and cleaned it down with the TB cleaner, an old toothbrush, and a lint free rag. what a difference.
TBdirty.jpg


TBclean-1.jpg




8. With the TB clean I allowed it to dry and attacked the MAF sensor (gently).


9. The MAF sensor is mounted in the air box lid, where the air inlet hose connects, with 2 Philips screws.
MAFhousing.jpg


Removing it is easy, just be sure not to touch any of the inner workings as this is a delicate and expensive instrument. To be safe I didn’t touch anything that resides inside the air intake. Sorry about the out of focus pics here. I didn’t realize until everything was reassembled.
MAFsensor1.jpg

MAFsensor2.jpg



10. Spray down the sensor using the MAF sensor cleaner only and allow it to dry thoroughly.


11. Leaving the MAF sensor to dry, reinstall the TB in the reverse order of the tear-down. Check your gasket where the TB bolts on. Make sure it doesn't need to be replaced and the it is free of debris before installing the TB.
IMG_0306.jpg


12. At some point go back to the MAF sensor and secure it back into it's housing.


13. Might as well replace the air filter and then install the air box lid/inlet hose.


14. Reconnect battery


15. Done.
 

cbetts

NERD!!!
Messages
3,182
Location
Rancho Palos Verdes, CA
My throttle body was a tad bit dirty:
2012-08-18_11-51-53_446.jpg


I think I found the source of the grime. Looks like a lot of oil has been reaching the vapor recovery tube.
2012-08-18_11-33-11_114.jpg


I guess the steep hills have caused the engine to inhale a little oil. Maybe I am suffering from the same issue as Alex with the burning oil on extreme climbs. You can see more evidence in the AirDoc:
2012-08-18_11-33-49_741.jpg


I spent some time with some cleaner and got it all prettied up. I even sprayed some cleaner on a rag to wipe out the inside of the intake manifold a bit.
2012-08-18_11-57-01_882.jpg


After reassembly, I shot some MAF cleaner into the MAF and let it dry. Not to noticeable on the test drive afterwards. The computer was acting weird and kept the engine running at 2500 RPM until I came to a stop. After driving around for about fifteen minutes, the problem went away.
 

cbetts

NERD!!!
Messages
3,182
Location
Rancho Palos Verdes, CA
I am having issues with the truck keeping the RPMs up. As I approach stop signs, I pop it into neutral and coast the last few feet. The truck insists at keeping the RPMs around 2000 until I am at a full stop. My ScanGauge is showing the TPS reacting the same as the RPMs. The only thing I did was clean the throttle body and MAF. Nothing else.

Opinions?
 

Griff22usmc

Needs a sponsor
Messages
41
Location
Wilmington NC
Crazy I thought I was alone for a long while. I just cleaned the throttle body... Definitely alot better, I was thinking maybe the tranny was going. Something like a clutch for a manual, because when I relieve the engine of stress it seems to calm down and steady. The AC also can have the same effect if running. Idk what it is but it's common for the H3 to rough idle.... Got me, a buddy was thinking it's along the line of a electronic problem... Idk where to start

Sent from my DROID RAZR using Tapatalk 2
 

cbetts

NERD!!!
Messages
3,182
Location
Rancho Palos Verdes, CA
One thing to add to the list . . . disconnect the battery for a night to reset the computer. Once I did this, normality was restored. I also noticed improvement in power comparing to how it ran before the TB cleaning.
 

Medic_Morgan

Well-Known Member
Messages
392
Location
San Diego, CA
Huge Seat of the Pants difference Chris. Doubt mine was ever cleaned by prior owner(got it used at 26k mi from lease dealer) and just did my cleaning at 43k mi. Here are my pics(before/after). Don't forget to swap out your air filterImageUploadedByTapatalk1349289798.253193.jpgImageUploadedByTapatalk1349289820.307041.jpgImageUploadedByTapatalk1349289839.984539.jpgImageUploadedByTapatalk1349289870.491949.jpgImageUploadedByTapatalk1349289889.755925.jpg


Sent from my secret lair bwaaahhahahahah
 

Medic_Morgan

Well-Known Member
Messages
392
Location
San Diego, CA
Make sure you have MAF specific cleaner and spray all over the unit(in, on, around). I suggest using gloves as to not contaminate the unit bc it's a very delicate/sensitive device. Then allow to dry on a clean towel. Real easy process to do at home :)


Sent from my secret lair bwaaahhahahahah
 

alrock

El Diablo
Staff member
Messages
10,442
Location
Scottsdale
Yes, remove it from the intake and spray it so that any dust and debris is carried away by the spray. I don't think you even need to put it on a towel as it dries very quickly and you don't want lint from the towel making it onto the MAF.
 

bebe

Moderator
Messages
1,375
Location
Dayton, NV
Mine is up for service. Been noticing some hard shifting in 3rd and 4th on the way home from Moab, pulled the resonator off because we noticed some seeping around the front of the seam, and it was full of sludge. Going to do the TB, Throttle Position Sensor and MAF.
 

IndyHummers

Well-Known Member
Messages
276
Location
Murfreesboro, TN
We'll like an idiot I couldn't figure out how to get the sensor and evap hose off the TB. No big deal, cleaned it anyway. What a mess. Had some concerns though. I had quite a bit of oil on top of my rear cylinder and a brown almost muddy looking goop inside of the tube that connects there also. Any idea what that could be and if there's any cause for concern?
Hopefully this fixes the 3 stalling at traffic lights. We'll see.
 
Last edited:

apellafr

Probationary Member
Messages
4
Location
Bethel, CT
Great write up, Just did this and changged the spark plugs to Bosch Paltinuim+4 the 2006 H3 running better than ever Thanks again.
 
Top