Coolant coming out of throttle body

[HeavyAsAChevy]

So I was driving down the highway and my truck started over heating real bad and then shut off going down the highway. There was coolant coming out of the throttle body. What would cause it to do that? Bad gaskets somewhere? Or did I kill the stupid engine. It’s a 1996 Sierra 4.3L V6

 

[Caman96]

Intake gasket failure.

 

[HeavyAsAChevy]

Ok. I was reading that if the intake gasket fails, coolant gets in the oil?

 

[454cid]

Dont the small blocks and v6s have coolant running through the throttle body via a hose, or was that just early TBI with the adapter?

 

[HeavyAsAChevy]

There was coolant leaking out of the air filter and it was pooled on top of the throttle body blade.

 

[east302]

Dont the small blocks and v6s have coolant running through the throttle body via a hose, or was that just early TBI with the adapter?

The 350 vortec didn’t, so I’d assume the six didn’t either (but I had a 302 with that and can visualize what you’re referring to).

Heavy - can you confirm?

So you have coolant coming out of the air intake (filter box) and it’s collecting on top of the throttle body? Do you have a picture of all of this? Kind of having trouble seeing how coolant could get sucked into the air intake unless you ran through something or the upper intake is somehow overflowing with coolant and backing up into the air box. Is the upper intake filled with coolant?

 

[HeavyAsAChevy]

So you have coolant coming out of the air intake (filter box) and it’s collecting on top of the throttle body? Do you have a picture of all of this? Kind of having trouble seeing how coolant could get sucked into the air intake unless you ran through something or the upper intake is somehow overflowing with coolant and backing up into the air box. Is the upper intake filled with coolant?

I couldn’t check to see if the intake itself was full of coolant, but I have just a k&n filter laying around in the engine bay(i know, not the best decision I’ve made) and it was overflowing out of that. I do have coolant in my oil though.

 

[HeavyAsAChevy]

So the engine is toast and can’t get it rebuilt. A remanned is gonna be over $5k cause my dad isn’t gonna let me do the install, so I’m super ticked off about it, but I gotta sell the truck. I’ll still be present on here, but not much so. I’m going to try to get another one, but for now I just gotta save $$$ cause of the dang market exploding.

 

[Schurkey]

Sounds to me like there's coolant coming out of the throttle body, and pooling on the air cleaner from reversion. Intake gasket leak, maybe head gasket or cracked casting.

"I" would want to do a cranking compression test; and maybe a leakdown test on all six before opening the engine up for anything except spark plug removal. Add in a cooling system pressure test, too. All the tools except the air compressor may be available from a parts-store loaner program.

If it's an intake gasket, it could be a simple fix. Replace the intake gasket. Change oil 'n' filter, pull the plugs, crank engine to blow out any remaining coolant in the cylinders. Put it all back together and drive away. Change oil 'n' filter again in a few hundred miles to assure that all the coolant is removed. Hope that the catalyst isn't poisoned. Depending on the results of the cranking compression/leakdown test, and the cooling system pressure test, this could be very do-able.

If this is your truck, why is Dad telling you what you can/can't do?

 

[Caman96]

Might be Dad’s driveway, so he calls the shots. Replacing a vehicle in this market might still be more than a new motor.