Grimey air intake manitfold

So I'm doing a bunch of work to the truck these past few days (headers, new clutch, plugs etc) and I decided to clean out the throttle body and MAF while the resonator was out of the way. Took the throttle body off.. and from the butterfly valve downstream is pretty dirty/oily/grimey. It's super clean up stream towards the resonator and filter. Not a speck of oil or dirt that way.

I can't figure out how it can be clean ahead of the butterfly and dirty behind it.. I should've taken some pictures but I didn't think of it until after I buttoned it all up again.

PCV valve is good.. checked that right away.

The truck runs great and idles fine. Only thing that seems different is my mileage has been worse than usual this winter, but I was just blaming that on the un-relenting cold we've had up here.

So, to the collective knowledge out there, what gives with my grimey manifold?

Bonus question.. Why are there 2 small coolant lines running to my throttle body?

 

The grime is deposited by Exhaust gas circulated into the Intake by the EGR system. So it's perfectly normal. Clean your throttle body with Carb cleaner and clean what you can of the intake and keep riding.


Second Question the coolant lines heat the throttle body to keep the butterfly from sticking in sub freezing temperatures. A stuck butterfly in the WOT position would probably be bad for the vehicle occupant.

 

The 2TR-FE does not have an EGR system.

 

Ok so how do you explain the gunk in everybody's air intake.

 

its oil

 

I'm not arguing about the gunk on throttle bodies. I'm just stating the fact that the 2TR-FE does not have an EGR. My Tacoma has this engine, and no EGR is listed on the emission specs label, and there is no EGR shown in the factory service manual. I know most all throttle bodies do accumulate gunk (often called coking) over time. Fuel fumes cause some of it, as does the PCV system. Do a Google search for throttle body coking, and you'll find plenty of info.

 

After looking at the parts diagrams I believe you are correct. Call it too many years of working on EGR equipped vehicles working against me. That and my 3RZ & 22RE were EGR equipped.


Good Catch on that one though.

 

Would the oil catch can help any of this?

 

Lots of good info so far. I've been looking at parts diagrams too..

There doesn't seem to be a EGR valve on this 4banger but it does have a vacuum switching valve.. and that seems to be associated with an EGR in the research that I've done so far.

Still trying to figure where this vacuum switch valve hooks up to..

 

Ha! Looks like the VSV is piped to just below the throttle body..

http://www.customtacos.com/tech.old...06toyrm/06toypdf/06rmsrc/rm2006ta/0060063.pdf

It must be where this crap is coming from.. it's probably normal, I hope, to look like that.

She ain't thrown'n any codes so I guess I won't worry about it.

 

It's not associated with an EGR on this engine. The VSV has to do with the fuel tank vapour canister purge. Fuel vapours are part of the deposits found on the throttle body.
All throttle body assemblies should be cleaned of deposits on a regular basis.

 

So if I put a good oil catch can in-line after the VSV and before the throttle body, that should eliminate the oily grime in the manifold, right?

Is that where most people put their catch cans?

 

there are alot of threads with oil catch can info just search for it and maybe that will answer this one, I think so but I'm not 100% on that.
you should post your findings if any!

 

All the catch cans I have ever seen were in between the valve cover and the pcv valve. The catch can would reliquefy the gaseous oil and catch it. I cleaned my intake/TB at 55K and didn't see anything out of the ordinary as far as buildup for that mileage. I did put a catch can on my 05 Mustang V8 b/c that engine would actually use enough oil to drop the oil level. All of it was going through the pcv system.

 

the crank case breather? Plug it up on the intake side, and get a mini filter to put on the hose end?

Iv done this on most other vehicles assuming the toyota v6 is the same?

 

Well I bought and installed an oil catch can, and I put it in-line from the VSV to the throttle body. Everything is clean up stream of the throttle body so that's why I put it there.

I guess we'll see what happens!

I'll post some pics sometime soon, hopefully.

 

No. You do not want to do this. Use a catch can or something but do not dump the crankcase vent through a filter into the air.

 

why not?

 

Do you know what the PCV System does?

Dumping the crankcase gasses into the atmosphere through a filter or not is called Pollution.

Pulling these gasses back into the intake and burning them in the cylinders is the best choice. That is what the PCV System does. It doesn't hurt the engine and prevents or at least keeps the pollution to a minimum. It also prevents gumming up inside of the crankcase and around the valve train.

http://auto.howstuffworks.com/positive-crankcase-ventilation-system.htm

 

I've had a catch can on my Prelude for 10+ years and have gone through several different methods of attaching it.. including venting to the atmosphere. In all my research over the years, I have never seen or read about anyone plumbing one into the EVAP system. Not to say it wont work, but I'm skeptical that the grime you see is caused from the EVAP system. Most grime near the TB or further downstream into the IM is caused by the EGR (which apparently we dont have-YAY!!!), the PCV system and breather on the valve cover, or dirt from a poorly filtered air intake. Good luck.. hope this works for you. Also, be careful with the emissions police because here in CA any modification to the emissions systems (PCV, EVAP, EGR, etc.) is illegal.