Liquid behind dash

[crazycarl]

I just want to make sure that what I am thinking is right on this one...

There is some liquid behind my dash towards the passenger side. I only notice it when I accelerate. It sounds like it is liquid being semi-sucked up through a tube and kind of bubbling somewhere. That is from the leaky transfercase switch? I fixed the switch and I assume the liquid is just from time driving with the bad switch?

What makes me second guess that is my truck sips coolant too, it magically disappears, no leaking on the engine anymore since I replaced intake manifold gasket. Carpet on the passenger side is not wet. Could it be coolant that i hear? (although I assume it's being burnt off in the engine: have replaced thermostat, heater hoses, etc.... I am going do the radiator test for head gasket leak soon)

But I just wanted to make sure that the liquid is indeed from the transfercase and need to follow previously posted transfercase directions. Or could it be a combination of things? I'd prefer to not be surprised when I go to replace the HVAC things...

Right now I am assuming it is not too pressing of a matter at the time since I've taken care of the T-case switch and if it is the head gasket, I can't do much for that anyways at the moment...

[roadrunner]

You may have air trapped in the cooling system. This can cause the gurgling/bubbling sounds in the heater core/system. I am unsure but think it may be possible to have a core leak out through the evaporator drain tube under the pass side firewall. Most fluid in vacuum system sounds originate in or near the center of the heater and in the brake booster area as far as I know. Get a pressure check of the cooling system and look EVERYWHERE. Under, on top, in cab everywhere. Additionally if you are losing coolant the recovery system may not be refilling the rad etc to capacity like it's supposed to as well.

[HenryJ]

More than likely it is coolant that you hear. The transfercase issue usually sounds like a hissing as the vacuum leaks appear.

Consider leaking intake manifold gaskets. That is really common. Dexcool eats them.

[killian96ss]

I would also guess air in the coolant, maybe from a clogged heater core, bad intake gasket, or air being sucked in from another source.

Steve

[crazycarl]

Gurgling does describe the noise better. I changed the intake manifold gasket about a year ago, the rear of the manifold was clogged with dexcool. Since changing it out, I flushed the system and went with the green coolant.

I also fill a little my overflow tank and it disappears too.

so next step I should pressure test cooling system?

[HenryJ]

...so next step I should pressure test cooling system?

Yes. Check for damp carpet on the passenger side too.

[crazycarl]

Yes. Check for damp carpet on the passenger side too.

I have checked carpet after driving and it has been dry. No obvious smell or stains of coolant.

Also driving it right now, there is little to no gurgling. Is there anything specifically that causes it to happen that I can do to help the search?

[HenryJ]

Might check the radiator cap. There is a good thread on caps. It can take some effort to purge the system.

[crazycarl]

Might check the radiator cap. There is a good thread on caps. It can take some effort to purge the system.

I replaced the radiator cap with one from Autozone ~1 year ago. Never looked at brand, just had them give me one. It is a Motorad, 16#. So I may follow others in the radiator cap thread and replace with a Stant. There is also some grime built up on it which I assume is from the Dexcool. I believe when I swapped the coolant and flushed it at around 85k miles, it was a first for the truck which had a leaky intake manifold for a while....

All that being said. i am starting to think Dexcool crud has partially clogged the heater core?

[HenryJ]

Might be time for another good flush!

[crazycarl]

I agree. Last time I used the Peak flush, this time I am going to use dish soap.

[killian96ss]

Prestone super flush works pretty good. Just put 1 or 2 bottles in, fill with water, drive for a day with this mixture, drain, flush with water, fill with green stuff 50/50 mix (depending on climate) and throw in a bottle of Redline water wetter for better heat transfer. It's also important that you use a flush kit that T's into the heater hose if you want to clean out that heater core.

Steve

[Lil-j]

, this time I am going to use dish soap.

Are you talking about doing this with the powdered kind, right?!

[crazycarl]

Are you talking about doing this with the powdered kind, right?!

No. Liquid degreaser. I forgot what brand people have used and I recall a certain brand not to use due to certain ingredients, iirc.


EDIT: after looking for the coolant flush post I came across a while ago, I found this: http://forums.s-10crewcab.net/viewtopic ... lant+flush

pretty much sums up what I am experiencing. I am looking forward to getting rid of this noise once and for all!

[rlrnr53]

A local radiator shop reccomends liquid Dawn dishwashind soap. We tried it on a grader that had a ruptured hyd. oil cooler, and it worked wonders removing the oil.

[crazycarl]

A local radiator shop reccomends liquid Dawn dishwashind soap. We tried it on a grader that had a ruptured hyd. oil cooler, and it worked wonders removing the oil.

Yes! Your posts were the ones I had seen. I went out and got some dawn today and hopefully will have time tomorrow to flush the cooling system and especially the heater core.

[bbgot]

I had a 2002 CC (now sold) that did this exact thing. Kind of a liquid sucking sound only on acceleration and mine did seem to sip a bit of coolant. I never did track down the source of the sound in the year or so I had the truck.

I had the transfer case switch vacuum problem and replaced everything involved when fixing that, so I'm pretty sure that wasn't causing it.

My best guess is it's the result of a problem with the intake gasket (I never replaced them in my truck), though I'm not sure how it would cause that sound. Even though you did replace the gasket, it might not hurt to give it another try (I've had to do them a couple times in other trucks when they don't seat just right the first time).

[ApproachMedium]

My crew did it once in a while, but now both my crew and my buddys blazer do it often. I think maybe they dont have enough fluid in them. My truck just had a V8 swap and my friends also had an intake gasket replacement. My friends was horribly crudded up with the Dex crap so its very possible that after it got flushed out it cleared up all the CRAP in the core and now im actually hearing the water flow like its supposed to.

[roadrunner]

I have had this sound on a couple vehicles and in both cases it was low coolant level which causes air trapped in the system at the heater core and the resulting sucking or whooshing sound when the engine revs up a bit on takeoff etc.

[ApproachMedium]

Interesting. Ill have to go get myself a bottle of coolant tomorrow afternoon.