Ok, so I take off my Injen intake for the first time after buying the car (I took it off because I want to cut it about 3" so it sits a bit higher off the ground and put on one of those hyrdo shields) and I notice all this green acidy looking crusty sh*t all up inside my TB, so I take off the TB so I can clean it and see that the inside of my intake manifold is caked in coolant (so says my dad who is a dodge mechanic) how is this happening? I notice that there is a coolant line running through the TB, is there a gasket that could be f'd between the 2 or something? I did some searching and found nothing except for a "TB coolant bypass mod" that I DO NOT really want to do if avoidable because I live in Canada where the winters are not fun, so how can I go about fixing this so it does not happen?? thanks in advance!

 

i say you take the intake off all together or make it a short ram.... thats crazy

 

... but that doesnt really help my situation? I need to stop coolant from entering my intake manifold through my throttle body I believe, my intake pipe isn't really effecting anything

 

new gasket time

 

No gasket will make a difference. Your TB might have a crack or something allowing the coolant to enter. There are no other coolant lines that run through any part of the intake.

Do the bypass mod. The purpose of the coolant going through the TB is to stop it from freezing shut, right? Well when you first start your car in the morning, the coolant going through it is the same temperature as the outside air, so how does it heat anything up?

And after the car is at operating temperature, the TB is warm anyway because the whole intake is aluminum and conducts heat.

The coolant going through the TB is pointless.

 

^ he said hes from Canada....maybe he should'nt bypass it....and what about the fuel going to his engine when it evaporates and drops the temps even more causing things to freeze up...dont imo. Check all gaskets around area and hoses

 

I coolant bypassed my TB during my engine replacement. Completely pointless system.

But on an OT note, and not knowing anymore about our intake manifold designs than I do, does the OP need to check his intake manifold gaskets as well? Perhaps one of his gaskets failed on one of the coolant jacket passages, and the system pressure is causing coolant to mist into the intake manifold and TB areas?

 

The fuel is injected at the bottom of the lower intake manifold, far away from the throttle body.

Once the car is at operating temperature, the throttle body gets burning hot just from heat conductance.

There are no coolant passages on our intake manifolds. I do not see anyway for coolant to get in there other than the TB. And +1 on the bypass mod.

You can always put the coolant lines back on the TB if for some odd reason you have a problem, as it takes like 5 minutes to do this mod.

 

thank you for your replies I think I will just do the by pass and then when winter hits see how things go, i'll just make sure I never drive the thing without being warmed up thats forsure

 

maybe i'll get a new TB in a bit, to be on the safe side as well

 

There is a seal between the TB housing and the IACV assembly which if it leaks can cause coolant to enter the intake via the IACV/TB air passage. You'll have to remove the TB to remove the IACV assembly to replace this seal (kind of an "O ring cross section type seal). Firstly, the Gen. 5 (unlike the Gen. 5.5) has the plastic upper intake plenum, not Al, so there is no heat transfer from the engine and it certainly will never get hot. Under certain conditions (usually a few degrees above freezing with quite high humidity) the TB can be prone to icing caused by the pressure drop and subsequent cooling at the throttle bore (put your fingers on the TB housing when the engine is running). That's why there is coolant directed through the throttle body on some engines. This coolant is bypass coolant and will heat up quite quickly (same as the coolant supply to the heater) as well. Depending on your location you may find that you can mod to delete the coolant supply to the TB and not ever encounter TB icing but in other areas you may not get away with it. Running rich with black smoke at the tailpipe and/or quitting at idle can be an indication of TB icing. Ask any old guy (like myself) that owned an old '50s or 60's car about carb ice, or any light aircraft pilot about "Carb Heat".

 

For some reason I was thinking you had a 5.5 gen...

Guy above me is right.

 

Not only that but the Throttle body is a seperate unit that is also aluminium. since this dosent get as warm as them i/m the expansion rates will differ and by having the coolant go throught the TB is prevents drastic temp difference and avoids the aluminum cracking. My advice is if you live in a cold weather climate then keep it on. if you live somewhere where below freezing isnt common you can bypass it.

 

+1 for both these guys.

I think you really may need the coolant to help heat the air in the intkae in colder climates or it will always have to run richer than it needs to. It likes the heated air coming into the throttle body. Since they build these cars for everywhere they have to be built for cold weather as well as warm where the coolant isn't needed.

It could be the O ring in the IACV section. My suggestion is to clean everything up and do the coolant mod for a month. If it is still clean after that you know the leak is there and then you make the decision to either try to live with the Mod (I wouldn't) or look to replace the whole TB.

If it appears to still be leaking you know it's the IACV and you know your next job.

Just my 2 cents.

 

Bypass it. It has to be the dumbest thing ever.

 

Agree.

The car wont run richer with or without it because the AFR is controlled by the o2 sensor feedback loop.

 

haha yikes everybody's got a different opinion! ok well i did the bypass yesterday but i didnt fire it up yet because the battery was dead so I'm going to today, I'll drive it for a month and see if everything cleans up in there, if it all looks nice I'll probably just buy a TB and replace it because it gets to be like minus 35-40 in the winter sometimes where i live, average -20's, it's summer now though so its plus 20-30 :-) too bad they don't make an aftermarket one :-(

 

Previously I posted asking for opinions about replacing the intake air controler gasket as preventive medicine.

The idea is that this will prevent coolant from damaging the electronics in the intake air controller, and also prevent the destruction of the ECU.

In previous posts, several people said there is no coolant to the idle air controller, and made other condescending comments.

Since in this post there is awareness of the coolant and idle air controller - does it make sense to replace the gasket?

My idle air controller (2001) still works well. I am thinking that carefully replacing the gasket (being very careful with the throttle body) might be possible without needing to relearn the idle - since the same part would be used. comments or suggestions please . . .

 

Anyone want to weigh in on this?

I am thinking preventitive maintence - cheaper is better -

the possibilities are:

1. leave it alone
2. replace the Idle air valve
3. replace the idle air valve gasket
4. bypass the coolant lines to the idle air valve - by plugging them, or maybe by looping the 1/4" line back after disconnecting the idle air valve

thoughts / comments?

 

And for those who have bypassed the IM coolant lines, what did you use to you cap them off?

 

While the cleanest way of doing this would be to cap off the little pipes, I haven't yet found any "coolant/heat" approved caps, it's just not something commonly used. Vacuum caps aren't approved for the heat and constant pressure that coolant puts on 'em, so what I did was cut the hose about 3" down from the nipple, thread a bolt in there, and clamp the hose around it.

Sounds iffy, I know, but that's how I and most everyone I know have done it for years. I'm sure there's a better way, but this suffices for me.

 

Why not just run a coolant line from the supply side to the return side to bypass the throttle body?

 

It is your IACV gasket, replace it..it is only about $3. No need to do the bypass.

 

Now that is an elegant solution, thanks.