Noise In Dash??

[thrasherflash]

My 1999 GMC Z71 5.3 has a strange gurggling sound in the center dash area. The sound is most noticeable at higher RPM's. It's sounds like the heater core may have some restriction. The truck only has 50,000 on it is it possable the core has clogged allready. If so hows the best way to fix it. I'm new here and hope to learn more about my GMC, thanks for any help you may have

[asepgrad98]

welcome. this problem has been discussed before, try i search. i believe the solution is to flush the coolant and keep the over flow jug overfilled.

[SteveCZ]

I had the same problem..... I simply overfilled my overflow tank. I filled it up to the top, ran it for a while, opened the cap to release the air (after it cooled), refilled it again, and repeated about 5 or 6 times.

 

Problem solved.....

 

Just make sure you use the Orange Dex Cool !!!!