Coolant leaking from throttle body.

Hello, first time posting because I can usually find exactly what I need to do without saying anything on here.
so i was having some troubles with my rpm’s being all over the place. Thought it was time for the usual TB cleaning. Noticed it had started leaking a little coolant underneath around the tps. Figured it was a bad gasket or I had put it in wrong. Well I think I have a bigger problem now.
I read a little bit about it being a coolant by pass pipe. I’ve never dug into the engine that far before. If anyone could give me some pointers/pictures related to this procedure that would be great. Also read it’d be a good idea to replace knock sensors and harness while I’m in there. Any help would be very much appreciated. thanks

 

The only coolant is at the Idle Air Control Valve quite possible you switched a coolant line with Vacuum so your sucking coolant into the throttle body.

For some reason Toyota likes to call them coolant bypass hoses.

 

Is it possible the IACV valve gasket is leaking?

 

Depends if the OP had removed the IAC valve and damaged the gasket. Did not have a new one or could not make one.

 

yeah..i was just wondering.Honda gaskets look like this...im not sure about his..

 

Toyota P/N 22215-62180

 

I’ll check that. I suppose if that is the case I should probably get into it and start cleaning either way. TPS gasket was only a couple years old. Replaced it the first time I took the tb off for cleaning. We’re at 110000 miles now fyi. Gotta change that on my post Id.

 

How has your coolant level been since you last cleaned your TB?

 

I noticed it was always low in the overfill. But never low in the radiator.

 

There sure is a lot of red at the intake manifold opening. It is difficult to imagine how it got there. It would have to be a pretty good leak via the IAC gasket. Hard to imagine how that could happen though. Maybe incorrect reinstallation of an old IAC gasket. IIRC, Toyota considers that gasket a single use item.

Here's what the one for the 3.4L looks like

 

Did you ever fix the leak,mines doing the same?

 

It looks like that gasket was allowing the the coolant jacket on iac to leak into the air/turbine switch....

when the switch was open....from the leak, it draws droplets straight down the intake.....

when its closed.....judgeing from pink forward TB....the flow/droplets would back feed into that iac air supply tube....
going backwards....and getting sucked into intake tube from the vacuum.....


thereby staining the very front of the throttle body.....


Very rare....dont see that everyday.....

that borders on a hydro lock engine.....if that catastrophically failed going down the hwy......you wouldn't even know what hit you....

these trucks can develop a number of cooling issues......got to stay on top of it....

reason why there's so many sitting on flat tires behind garages and backyards....

 

Its a good time to replace those fluid hoses with braided silicone......and new clamps.

when you have all that apart....

$48 HPS 5/16" ID blue high temp reinforced silicone heater hose 10 feet roll, Max Working Pressure 85 psi, Max Temperature Rating: 350F, Bend Radius: 1-1/4"

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