Hi guys.

I pulled my throttle body out to replace the seals over the weekend and found that the coolant lines have started rusting. The rust has only formed in the first 10mm of the line, which is the part that is covered by the rubber hose. The rest of the throttle body is in like new condition, so I was surprised to see how badly one of the lines had rusted.

I've managed to sand back the rust, although there's still some pits that might be hard to smooth out without stripping back too much metal.

Is it possible to buy some new coolant lines and replace them without much hassle?

If I can't get some new lines, it would need to be sealed/painted. Can anyone recommend which products to use?

Thanks

 

I bypassed the throttle body and just connected the two coolant lines together. Had it this way for the last couple years. Seemed to have picked up some torque too, but it may be my butt dyno fooling me

 

The coolant lines are rubber hoses and cannot rust.

 

nightwalker: I want to keep the stock setup with coolant running through the TB.. don't like the idea of having the plate seize due to overheating, especially with the stock egr system still running.

sparky: I thought my first post was clear enough. Coolant travels through the rubber tubes, which attach to the TB metal lines/pipes/tubes.

 

You have to buy a new throttle body if you want new metal lines. And if you don't want the corrosion and rust you got on your old one, then you need to change your coolant more often.

 

Sorry. Not meaning to be a *****. I looped mine about 6 years ago. My recollection may not be very accurate. Old age plus high levels of coolant(alcohol).

If there are metal hard lines you can replace them with high temp braided rubber or silicone coolant hose. If you wish to preserve your original stock hard lines then i would just sand them down and refinish with a silver anti-corrosive finish. Otherwise, go to the dealership and order the replacement parts. Take care

 

the only time you'd need your coolant lines are if you live in a CONSISTANTLY cold area....like alaska. -30* mornings. all it does is keep it warm to prevent condensation freezing and wrecking the seals. alot of people really over think the whole TB coolant lines.

 

Thanks for the input guys.

I'll start by coating them with some anti-corrosive finish and replace the coolant. If the rust comes back I'll look into the braiding/silicone options.

 

I didn't loop mine, i just purchased caps and capped them off. I live in florida so have no cold start issues.

 

I dont run coolant through my tb either but do the lines really need to be caped or looped? one line is in, one line is out. If nothing is going in anyway whats the point of caps or looping?

 

you can loop them.

 

Many years ago I owned a 67 VW bug. If you needed carburetor heat you had to stop, raise the engine cover and flip two levers. I had the throttle plate get sticky with ice on 60 degree days if the air was humid or if it was foggy out.

An Evo has a turbo to heat the air if boosting but if you are just idling around you could still have the same problem with an Evo if no throttle body heat.

If you are worried about the rust on the pipes at the throttle body I suggest you do some looking around. There are also coolant hoses to the turbo and to the heater. You will find the same rust there.

 

The coolant in the TB isnt there to keep it cool,its there to keep it warm in the super cold areas so it doesn't freeze over. Bypassing it will keep your TB from heat soaking and youll pick up a little bit of power.

 

It's also there to stabilize your idle by controlling air flow through the throttle body with the wax plate that heats up and cools down.

Sorry to bump this, but I just had a coolant line break back there, so I'm doing my research on replacing it, etc. The usual forum crawl to fix a problem.

 

If replacing the hoses, you will need to pull some things to make room to work behind the engine - no biggie. It is also helpfull to have a long nose pliers bent 90 degrees to work the clamps.