Throttle Body

Status
Not open for further replies.
Joined
Aug 3, 2011
Messages
286
Location
Athens, GA GO DAWGS
I have two Nissans with the VQ40 v6 engine; an 08 and 06 year model. I just cleaned the MAF sensor and wanted to clean the throttle body until I read up on it. Is there a way to avoid the idle air relearn procedure? I dont want to have to take it in to the Nissan dealer.

I also have a 2013 Toyota Tacoma with a 4cyl engine. Seems it doesnt have to do the pedal dance to relearn normal idle rpms.
 
I don't know why people write that online. Ive cleaned them, taken them off the car, disconnected the battery. 3 different Nissans new and old. Never did a relearning procedure. Just drove for 50 miles and all was good by the next day. Should go the same as your toyota.
 
The newer (2011- present) Nissan DO require that they get re-program if you touch the throttle body. Don't risk it. That is a part Nissans are really picky about. Guy above me doesn't know [censored] about it. Mine had to get cleaned from there. You are either better off taking it to a mechanic to just pay to get it reprogrammed or risk it. I would just spray it without touching it much.
 
I’d spray with the throttle body on car, engine running, a second person doing revs up in cabin. But some would say you shouldn’t ever run without an air filter on.
 
Originally Posted By: FermeLaPorte
Guy above me doesn't know [censored] about it.


Considering he's done (3) different Nissan vehicles, I'm not sure how valid your opinion is....
 
Originally Posted By: dawgn86
I have two Nissans with the VQ40 v6 engine; an 08 and 06 year model. I just cleaned the MAF sensor and wanted to clean the throttle body until I read up on it. Is there a way to avoid the idle air relearn procedure?


I have an '08 VQ35HR and have cleaned the throttle bodies 1-1/2 times. I say a 1/2 time because the 2nd time I only removed the intake tube while the first time I removed it from the plenum (but left the electrical connection in place and battery connected). I also moved the butterfly valve ! Both times !

Even if you need or want to do the idle relearn, it's not difficult and does not require a trip to the dealer.
 
Originally Posted By: Superflan
I’d spray with the throttle body on car, engine running, a second person doing revs up in cabin. But some would say you shouldn’t ever run without an air filter on.

Sure you can do it with the TB on the car but No need to have the engine running. You simply gain access to the TB (remove intake components). Then block the butterfly open and spray carb cleaner into the TB. Then use a toothbrush and rags to scrub and dry the inside.

But TB cleaning is over done and is not really that important. Not really that much can go wrong with a TB. The air filter cleans almost all of the dirt.
Is mechanics throttle body recommendation legit?
 
Originally Posted By: Dave1027
But TB cleaning is over done and is not really that important. Not really that much can go wrong with a TB. The air filter cleans almost all of the dirt.


It may vary by design but on Nissan's VQ engines the PCV system feeds back into the intake and it WILL get a build-up on the face of the butterfly valve as well as create a 'ring' inside the throttle body bore where the valve sits when 'closed'. On VQ engines, this can and does cause idle fluctuations - unsteady idle or when you stop and it drops down to 650-700 idle RPM, it will flutter and drop down to 400-500. Cleaning it, at least for me, SOLVED that.
 
Originally Posted By: hallstevenson
It may vary by design but on Nissan's VQ engines the PCV system feeds back into the intake and it WILL get a build-up on the face of the butterfly valve as well as create a 'ring' inside the throttle body bore where the valve sits when 'closed'. On VQ engines, this can and does cause idle fluctuations - unsteady idle or when you stop and it drops down to 650-700 idle RPM, it will flutter and drop down to 400-500. Cleaning it, at least for me, SOLVED that.


So Nissan is routing crankcase blowby/oil vapors through the throttle body? That's a screwy design. In that case yeah I agree. Something like that you'd have to clean all the time. Normally PCV is routed directly to the intake manifold bypassing the TB.
 
Originally Posted By: Dave1027
So Nissan is routing crankcase blowby/oil vapors through the throttle body? That's a screwy design. In that case yeah I agree. Something like that you'd have to clean all the time. Normally PCV is routed directly to the intake manifold bypassing the TB.

Googling "oil buildup throttle body" gets results the refer to Jeeps, Miatas, Toyota pickups, Chevy Tahoe, etc, etc. One person's comment was

Quote:
It’s most likely from blow-by gasses combined with engine oil. It comes from the PCV system. The PCV system sucks air out of the crankcase and feeds it into the intake, usually at or near the throttle body.

There was no reference to the vehicle or engine design in that case.
 
Almost every car will get a buildup of black stuff throughout the intake manifold, including the inside of the throttle plate and the downstream sides of the throttle body. It is is oil and unburned gas that carbonizes to a gooey sticky mess. If it is severe it can cause the plate to stick, resulting in driveability problems at idle and just off idle.
 
Last edited:
2012 Altima, 2.5S, 110K miles (180K KM). Just cleaned mine to cure a bad idle, stumble on acceleration and error P101 that wasn't fixed with a new MAF sensor.
Undid the TB, but left the connections on and made sure not to move the butterfly. Backside of the butterfly was a mess with a ton of black deposits. Sprayed it all off with TB cleaner. Runs like new, no error codes, no hesitation, not idle issues!
 
If the battery is disconnected prior to starting the throttle body cleaning, there should be no need for the relearn procedure.
 
Status
Not open for further replies.
Back
Top