Hey guys, Im pretty new to the forum and have seen this problem on here before, but couldnt find it again. If any of you can please tell me what is wrong with my jimmy.
OK I have a 1999 gmc jimmy 4x4 with 201,000mi on it.
1) I hear a gurgling under my dash as my motor revs higher. I tried to track it down and it seemed to be comming from just over the tranny hump under the dash. It sounds like a gurgle or water passing through a tube?
2) When my tranny shifts down to go up a grade on the highway, air starts blowing though the vents even if the ac and air is off, my heater works, butmy ac does not work if that helps narrow the problem down any.
And thats my problems. Any amwsers would be greatly appriciated
-Ryan

 

1) Probably low on coolant, low rad due to a leak in the cooling system....check level and look for leaks.

2)Hmmmm......Possible vacuum leak, maybe a vacuum hose.....

 

its not over heating and the raditor reservior is full. I probably should flush it because it hasnt been done yet, by me at least.

 

I'd suggest flushing your heater core. More than likely, you have a clogged core and the water is gurgllng because of this clog. If you pull both of the hoses off of the firewall and flush through both of them you should be able to clear the clog if it isn't too bad.

One thing to note, if the clog is real bad, there may be leaks that are currently being held shut by the clog. If you are able to clear the core, you may open up a leak.

If you use a garden hose to flush the core, be careful not to let the pressure build up. This is especially true if the core is clogged or partially clogged. A garden hose is capable of applying quite a bit more pressure than a cooling system is premitted to build under normal operation. 16lbs is what the rad cap is rated for and most water systems are around 40-60psi.

 

I was driving the other day and a rattle devloped around where the sound is comming from. It dosnt sound exatly like water, but likea running pump under the dash. I went wheeling and the rattle I just noticed this morning and it sounds like its rattles more when I can hear the pump sound get louder.