Dude, where's my dexcool?

Pioneer · July 26, 2004

I have to refill my 96 K2500 suburban about once a month.

There are no puddles, no rad leaks, oil is clean, no steam in exhaust - where is this stuff going?

2000 GMC · July 26, 2004

Might need to replace the radiator cap.

intruder217 · July 26, 2004

head gasket.

obbop · July 27, 2004

I'd be tempted to pay the $20 or so and have an oil sample tested to see if the missing coolant IS reaching the oil. I believe that would be the cheapest way to determine if the coolant is leaking around the head gasket or some other place where it can reach the oil.

Hopefully it IS the rad cap. That's a cheap fix.

99-2door · July 27, 2004

What engine do you have?

Look on the intake manifold. There is quick connect water inlet fitting there, on the passenger side toward the front of the engine. Does the fitting look a little corroded?? If so that could be where your leak is. The fitting may be super brittle. When you buy a replacement, make sure they give you the improved design. (However tempted you may be to replace this fitting with a simple nipple, don't do it. The fitting has a resricter in it that regulates pressure to the heater core. They will blow out like crazy if the thing is removed.)

Also check the weap holes on the water pump to see if fluid may be leaking out there. I had one that never would make a puddle, but would still leak enough to lower the coolant level.

Typically a bad radiator cap allows you to smell coolant at the front of the truck.

Wingnut · July 27, 2004

What engine do you have?

Look on the intake manifold. There is quick connect water inlet fitting there, on the passenger side toward the front of the engine. Does the fitting look a little corroded?? If so that could be where your leak is. The fitting may be super brittle......

Aren't some of them towards the back of the manifold (pass side)? The one on my neighbors 97 was.

So is the one on my 92.

But yeah...They snap right off when you put the wrench on them. Total PITA.

MS3DALE · July 27, 2004

The part number you want on that connector is 15622861,and on the big blocks it is toward the front of the intake.

Mattt · July 27, 2004

Its probably burning up. Ive seen 3 different trucks of that generation, my old one included that all had the same problem. Its the intake manifold gaskets. They are a semi-hard plastic, and they WILL leak over time. The coolant enters the intake tract because of those gaskets hardening over time. You can help the problem by checking the torque on the intake manifold bolts. On my 5.7 there were 8 total, 2 in each corner of the intake. That helped on mine when the problem started, but it eventually gets to where you have to replace them. Thing that sucks is its an $800 job, and they only offer the same style gasket, so it will happen again. Good luck.

OUMike · July 27, 2004

head gasket.

Definatly be my first guess..

Pioneer · July 27, 2004

I'll get an oil test and look at that manifold fitting.

I was wondering why the intake gasket was done already by the previous owner (I have the receipt). I'll have to take a look at the date on the receipt to see how old the job is.

Thanks for all the info and advice!!!

99-2door · July 27, 2004

What engine do you have?

Look on the intake manifold. There is quick connect water inlet fitting there, on the passenger side toward the front of the engine. Does the fitting look a little corroded?? If so that could be where your leak is. The fitting may be super brittle......

Aren't some of them towards the back of the manifold (pass side)? The one on my neighbors 97 was.

So is the one on my 92.

But yeah...They snap right off when you put the wrench on them. Total PITA.

Nope, on the TBI engines they are on the back. On 96-up they are near the front.

Here is a pic of the one on my Tahoe.

Wingnut · July 27, 2004

My neigbors 97 Tahoe had it in back.

I know this because I spent 3 hours f'n with it. I'd go take a pic, but they sold it, and got a Trailblazer.

That's weird.

99-2door · July 27, 2004

My neigbors 97 Tahoe had it in back.

I know this because I spent 3 hours f'n with it. I'd go take a pic, but they sold it, and got a Trailblazer.

That's weird.

Are you sure it wasn't a 95? I have worked on hundreds of these Vortec 5.7Ls and they have all been the same.

Did it have the breather box that says Vortec or a round filter housing?

Wingnut · July 27, 2004

Not sure, all of that was off by the time I got over there. I am sure it was a 97 though.

D@mn, I gotta go bug him later. Just to make sure that I wasn't smoking crack that day....Not sure...It was white.....In a pipe....Is that bad?

99-2door · July 27, 2004

Not sure, all of that was off by the time I got over there. I am sure it was a 97 though.

D@mn, I gotta go bug him later. Just to make sure that I wasn't smoking crack that day....Not sure...It was white.....In a pipe....Is that bad?

Wasn't that a pixie stick?

you are just like me.....You won't be able to rest till you know for sure