How to: Cleaning a Throttle body

Yes, I can attest to the BACKside of the throttle body accumulating gunk. This is why I'm not convinced spraying cleaner from the front will really clean up an overdue throttle body. Thick and sticky stuff, definitely would not come off with spraying alone, needs toothbrushing. I guess the most important is to clean at least to where the butterfly valve seats, beyond that not as important, maybe you can do at least that while mounted.

With it off you can clean the remainder of the tube to the intake manifold.

Back before cleaning:



Front before cleaing (air intake side not too bad actually):


Notice the hole there in the body; I suggest spray, scrub and spray with the throttle body upside down to keep from washing the crap down that hole and into the IAC valve.

Back after cleaning:


I really like Peru's idea of "sealing" the air cleaner seat with grease. We definitely want all the air to be sucked through the filter, not find its way around the filter should it begin to get clogged up. Going to try that.

 

nice write up, should have taken an after pic so they can see the difference.

 

I did include after-cleaning pic of back of throttle body above.

But here is more :

After cleaning, front:


Re-mounted:


IAC valve, removed for cleaning (yes, I had to take the whole thing back off again to do this, if your throttle body is bad, be careful about where your slurry goes):


All at your own risk of course ! Real mechanics love it when you come limping in tail between legs with a screwed up vehicle after botched do-it-yourself, don't they ? Ugggh. Good luck, make sure you have plenty of time, don't hurry and be careful.

Reminds me of a sign at a mechanic:
Labor rate $90/hour
If you watch $110/hour
If you help $140/hour

 

Like I e said before -- you learn something new everyday. I've only taken throttle bodies off of 4 different bike two of which have 2 cyl a TB for each. I've never seen that build up on the back side. Must have something to do with the fact that the TB on the taco is feeding 6 cylinders ore something like that -- I have no idea. I'll post some pictures fo the TBs off my R1150GS -- I have it all taken apart in the shop. They are spotless (almost).

The idea came to me from not being able to mount a carb on a husky 610 I have so I greased her up and she slid righ on the boot. The next time it came off I noticed the build up which I am convinced would have made it past the surfaces. Also keep in mind that I run my bikes hard all day long in very dusty conditions. Your average taco is not going to see that amont of dust and the resulting reduction in pressure on the back end of the filter unless you never service the air filter. It certainly can't hurt (don't put gobs of it on) and help during install.

Again I'll post pictures later

 

Well, I'd be interested in hearing/seeing others; this did seem excessive like maybe something's not firing right with my engine, what is all this gunk from what should be the CLEAN side of ignition? It's 4-cyl 2.7l by the way.

OH, and one other tip; it really messes up your toothbrush so don't use your own. I used the wife's and just ran it though the dishwasher after.

 

I used the wife's and just ran it though the dishwasher after.

The carbon build up on the throttle body is normal from my experience

 

just got it layin around, so if it will work and not screw anything up then why not.

i know brake cleaner cleans a lot more shit than brakes, so i guess its worth a try. but i dont want it to start to erode anything inside the TB

 

Based on my experience I'd say you are drawing dust in from somwhere after the filter and before the TB. There is a difference between dust and residue as a result of combustion. Che k the matting surfaces of the intake. My TBs looked like that before I started to pay more attention to sealing aspect of the intake.

Also -- do you use an after market air filter If so pay particular attention to the sealing gasket of the filter. Do you frequent high dust areas or do you live in the dessert. If so everything mentioned above is particularly important.

I'll try to post picture of the TBs of my BMW bike. The TBs have been replaced but the have 49k miles on them and they are very clean as they should be. Dust in an engine is not a good thing at all especially if it's high silica dust.

 

Couldn't you just put tape over the hole first so the cleaner and junk doesn't get in there when you're doing it?

 

ya hes right, i just bought a cheap can of carb cleaner and it worked perfect.

 

Here are some photos -- IMO there is no reason why the Tacomas shouldn't look this clean. The captions have the details. Keep in mind that this bike has 89K miles on it and has been from AK to Baja more than once plus many hundreds of miles on fire service roads. Had to replace TBs at 40K -- dont ask, BMW aint as good as they think. There are the photos of both the first set and second -- pretty much the same. 2nd set has never been cleaned. and the first set only once. Notice the o-ring on the TB in one of the photos. its there for a reason. despite that o-ring dust got past it. after the grease no dust any more.

one other thing on the trips to baja 80% was dusty dirt roads. see link at the bottom for some pictures of the conditions -- so that you can see i am not BSing.

One more point this model bike runs lean from the factory so as to pass emissions -- that might be the reason for the relatively clean combustion side of the TB as compared to the Taco

I tried to link the individual photos -- didnt work

here is the link to my smug mug repair photos

http://irazu.smugmug.com/Motorcycles/Repair-Photos/12103644_nZsMW#860164614_xt7SD

http://irazu.smugmug.com/Travel/Baja-Mexico-Trip-20022003/789973_CLqXt#35063478_ddeAm

http://irazu.smugmug.com/Travel/Baja-20052006/1147796_6QNkb#53531113_RMSDn

 

That TB looks brand new. I'm starting to think of some way I can use grease to catch the tiny stuff, but without coating the inside of the ductwork and not impede the airflow at the same time. On the 3.4 (not sure on the 4 bangers) the pipe between the air box and TB is corrugated. Think putting grease in the "valleys" inside would help, and prevent the grease from eventually creeping up to the TB?

 

I only grease the connection points of the intake and exhaust. The only other place I grease the whole innards is in the airbox where the filter resides on the intake side (dirty side) the BMW filter air box draws air in and creates a vortex as the air is drawn into the filter. every time i change air filters i wipe the inside walls and re-grease. The amount of crud is amazing but not surprising. I figure it increase the life of the filter. all that crud would be stuck in the filter instead of the walls if it weren't for the grease. It may be a bit over board but on a typical Baja run there are easily over 800 miles of very dusty roads and no where to buy filters.

Also i am about to open a can of worms with my following comment but IMO the K&N filters suck. If you dont keep on top of them the dust WILL get past the filter. I have proven this on several bikes. I use them but i clean and oil when i see they need it and i inspect all the time. I clean them way more often then is claimed by to be needed by K&N. for dusty trips i go with OEM -- around town here in Seattle where it rains all the time and there is little dust it is less of an issue. What happens with the filters is that the real fine talk like dust embeds itself in the filter and draws the oil out of the filter. Once all the oil is soaked into the dust from the filter the concept behind the K&N become null and void because there is no more oil so the dust sneaks past the clumped dust that has already dried up all the oil.

K&N + dust = bad unless you keep ontop of it and still it can be bad.

K&N + normal city driving + regular inspection = ok but not fail proof.

dust + cylinder walls and piston rings = very bad over time silica is like sand paper.

so if you are anal about clean oil and what type of oil you put in your engine and dont worry about dust in the intake then you are still doing harm to the engine.

 

I did the "deck plate mod", so the front of my air box is open to anything that wants to get into it. Think maybe I'll grease up inside the box on the intake side of the filter tomorrow. Have some high temp synthetic wheel bearing grease in the garage, is that ok to use?

 

any reputable manufacturer (mobile, shell, valvoline and the specialty manufacturers) will do fine if they say high temp. continuos temp rating is in the 225 to 275f range with spikes up to 400f.

I am not sure but the only place on the engine where you will see temps above 225 is at or very near the exhaust.

what you are looking for is a high dropping point

ASTM D-556 is dropping point (look it up on the web for more info) is the temperature at which a grease passes from a semisolid to a liquid state under high temps or as we say -- comes unzipped.

look up the technical data sheet on the net, there should be some fun info in it -- it should be there. I would be surprised if the temps anywhere along the intake line get above 100 deg. anything over about 110 is too hot to keep your hand on it. that plastic close to the filter on the intake line would burn way below the dropping point of any quality grease so to make a long story short dont worry about it at all.


one other thing -- we have all heard of the term snake oil salesman. it holds very true for the lubricant industry. I wont mention any names but many make hefty claims which are not true and in some cases impossible. again mobile & shell are going to stand behind their claims.

 

Thanks Peru, sounds like something to do after the detailing tomorrow.

 

You are welcome

Remember the only place grease should be placed is where the lines join. A thin film will suffice. You do not want any grease getting drawn into the tbs or anywhere else. Won't be the end of the world but I'd avoid it. It is not nessesary to grease the walls of the intake line. What I mention above is in the air box of that bike. In that design there is no chance for the grease to migrate into the filter and plug it up. On the taco that is not the case

grease in the air filter is deffinetly bad. Again the only reason I did the air box is due to severe conditions where ther is no chance to replace the air filter.

 

Yeah, that might work, but you are taping onto a dirty surface and might not stick; maybe wipe that area off first.

Taking off the IAC does have some risks, stripping the screws or tearing the rubber gasket or something.

I think if you just cleaned it while upside-down or at least after scrubbing when you re-spray (to sort if rinse it out), have it any way except that hole on the bottom acting like a drain, it should be ok.

 

Yes, I have K&N air filter but a stock intake. I've had the truck 7k miles and just pulled it, it was very dirty, I should have addressed it before now. But in very good shape, soft pliable rubber gasket mating surface etc.

I got the filter cleaning kit from AZ and cleaned it well according to instructions, let dry and re-oiled it. And, with advice here, cleaned the mating surface on the air box, put a little film of grease around the mating surface of the filter before replacing.

I live where there is little dust but frequent National Forest areas in the Sierra Nevada mountains here in CA during the summer, can be somewhat dusty but nothing like Baja I'm sure !

 

What is the ICA exactly?