BP1203

Wife's RX at 70k-figured I'd clean the throttle body, but refuse to pay dealer $200 to do something I'm sure I can do myself...anyone have directions or video? Anything else I should do?

Clutchless

Since the Highlander 2nd gen is a mechanical twin, these instructions from Toyota Nation should work. However each vehicle has different engine covers. The RX has more plastic covering to make our vehicles Lexus tomb like quiet (not). To remove the pins, push in the center, then they can be pulled out. After they are out, you may need to push the pin back in a bit to line it up properly for re-insertion. Do not push too hard doing re-insertion as the pins can also be removed by pushing hard on the center part.
Here is the link to the Highlander maintenance page, which has a lot of other great information http://www.toyotanation.com/forum/12...fications.html

I would also put a bottle of Techron Fuel System Cleaner (or the 3M stuff in the kit below) in the gas tank. If you go to Amazon or Auto Zone etc, 3M and CRC both make throttle body spray cleaners.

salimshah

But why? It is normal to get thin carbon layer ... which gets thicker over time. Is the dealer suggesting that it be done?
Usually trouble becomes noticeable when you have idling issues and it is best to clean the intake at that time along with idle control. I would say leave it alone till that time.

Salim

tempestv8

I would have thought that only diesel engines fitted with exhaust gas recirculation (EGR) would periodically require some kind of cleaning for their intake. I'd say that the throttle body on a 2GR FSE engine would be quite clean all through the life of the vehicle. I wholehearted agree with what Salim is saying above.

BP1203

This is what had me thinking about it...dealership "recommended", but they also recommend a lot of things not needed.

https://jalopnik.com/heres-how-to-do...car-1822054225

Clutchless

It depends how obsessive you are about preventive maintenance, although it is a known dealer profit center when sold prematureley, same as with fluid flushes. However if all is running well I would just throw some cleaner in the gas tank, unless like me you are obsesseive. I have already done 2 intake system (de-carbon) cleanings, but I have the fluid drip tool in my garage to do it at home, so the cost is minimal just my time and some extra cleaner. I have yet to touch the throttle body.

11bravo

TB cleaning is not preventive maintenance, and need not be done without specific indications. It is a HUGE money-maker for dealers. If you use Top Tier gasoline, such as Arco, Chevron, Mobil, Costco, you should never have to clean your TB. Also if you use Top Tier exclusively, there will be no reason to add Techron, as the cleaners in Top Tier equal or exceed the cleaners present in Techron.

salimshah

Throttle body [modern day vehicles] passes air. The carb build up is due to vapor recovery and some back flow. There is also internal engine breather that gets ported in. Light golden patena is expected as the vehicle is used. I attribute to vaporized oil being deposited.

Salim

BP1203

I put a can of BG fuel cleaner in every 10k, and do all the other maintenance. Change air and cabin filters every 12 months regardless of mileage. At 90k I'll change the spark plugs and diff/trans case fluids (did trans fluid change at 60k).

Thanks for the feedback, everyone.

MellonC00

On My Gen 1 my throttle body needed cleaning after the first 120K miles. Then, it needed it about every 60K. I don't know why. This occurred with air filters that were changed every 15K miles and using either Redline fuel system cleaner or Cheven Techron every 5k miles. Otherwise, it would idle really rough or simply die after starting. Eventually, I had to replace the throttle body around 200K miles.....

of course, this need not apply to lease owners who trade in cars every 3 to 4 years.

salimshah

In first gen you were getting oil/oil-fumes through the PCV .. which is normally expected to allow unburnt gas vapors.

Salim

11bravo

The Gen 1 motors were known to have excess oiling, which created the dirty TB. The TB was not the actual issue, but was a sort of "depository" for that issue, which affected everything else.
Even so, getting 200K miles with just two TB cleanings, then replacing the TB, is not a terrible record (maybe for a Lexus it is, but not for many cars).

How many miles did it have when you sold it? Was the trans ever rebuilt?

Jim

MellonC00

Thanks for the info. It's still running nicely. I have it still and drive it every Sunday about 20 miles. I have now about 253K miles.

N4TECguy

Seeing as how no fuel passes over the throttle body, it doesn't matter if you use race gas or avgas, it doesn't affect the problem at all. Please do not add false information to the internet, there is enough out there.

This is a problem that is affected by engine design, oil characteristics, and PCV valve functionality. It doesn't care whether you believe in Techron or BG fuel cleaner. It doesn't care if you use Shell gas. None of that affects this.

11bravo

So, let me see if I understand you correctly, and please be patient with me, as I am kinda slow. Are you saying that the EGR system does not recirculate unburned gasses, including fuel, through the intake? I am really surprised, as I thought the entire purpose of the EGR was to recycle unburned fuel particles and other emissions through the intake to be burned again, in order to reduce pollution.

Again, I am kinda slow, so help me out here...if the unburned gasses ARE recycled through the intake (throttle body), would they not contain fuel, carbon, and other particles? If not, how in the world would a TB every get carbon build up, if not for the EGR? And, if that is how the TB does get carbon buildup, would it not be wise to use the cleanest possible fuel to reduce unburned particles passing through the TB? Now, if that is correct. would it not also follow that Top Tier fuels, which are so classed because they far exceed the minimal standard for added cleansers, should be used to help prevent unburned particles from passing through the TB?

Again, I am an old man, and kinda slow, but I sure thought that is the way it worked.