We own a 2009 GMC Savana. We have been having constant problems with the heat in the cab. We have been told that we needed to flush the cooling system. After that we needed a new rad. Now we may need a new heater core as well. Could this be caused by the dexcool antifreeze?:

as much as i hate it i dont think your truck is old enough to cause that kind of damage. how many miles? is it under warranty? did you put any additives in there?

It has less than 3000 kms. No additives have been added at all. They say that I needed to have a ground strap put on as well. Warranty has been denied because we have a cleaning unit installed.

i dont see how a cleaning unit would cause those failures, radiators plug or leak same with heater cores. you may have to try a different dealer or get the opinion of a non affiliated shop. and if those things are actually bad the dealer should be responsible because the coolant that they put in is supposed to last longer than that. as long as you didnt add anything to the coolant they should be responsible. i would try to get away from what ever dealer you talked to though it sounds like they do "shotgun trouble shooting"

Beleive it or not this is happening at the dealer that we have leased these from!!!! Also we have the same problem happening with a 2008 GMC Savana as well.

Sorry the 2008 is a Chev. Express

Can you be a little more specific on "constant problems with heat in the cab"? Is the problem you get no heat (possible bad thermostat) or it varies up and down from hot to cold without you adjusting the temperature (possible coolant passage blockage, and reason for flushing). It sounds to me (blocked rad, blocked heater core) like someone put Stop Leak or something like that in the cooling system.

Your dealer is telling you what you need to do, but needs to tell you why. Ask the dealer why they think you need a new rad and heater core, and ask them to explain to you how that could be related to a cleaning unit.

Go to an independant rad shop, have them evaluate the vehicle and explain everything to you. Ask them if the failure could possibly be linked to the cleaning unit. Armed with that information, go back to your dealer and challenge them on this.

3,000 kms on the truck indicates this was a pre-existing condition, and should be covered on warranty.

Thank you for your help. The 2009 has been to 2 dealers and an independant shop that installed the cleaning unit. 1st. cooling system flushed. 2nd. @ Dealer Flushed cooling system and stated that the outlet hose was cold so there was no heat. 3rd. Back to Dealer pressure tested cooling system. Claimed to have found debris in cooling system. Flushed again still no heat. 4th. To Lease Dealer They found debris in the rad again.Then did all of the above again & then replaced the rad and put a ground strap on also stated that a new heater core may be needed. We picked up the van and found within 5 hours no heat again! It will be going back soon. Up to this point we have paid $800.00 which isn't too bad I guess... But it is a 2009!

If you already replaced the rad, the cooling flow issue could be internal to the engine, or the heater core could be plugged up. If the engine passageways were plugged the engine would be overheating and you would be seeing bigger problems than no heat in the cab, which leads me to believe the issue is heater core.

Makes sense to replace the heater core, but at 3,000 kms this should be a warranty issue. The entire $800 should be a warranty issue.

i think the coolant is supposed to be good for 5yrs so yep i would say they should pay for the flushing new coolant or whatever comes up.

does that truck have a cabin filter? maybe you are sucking up a bunch of dust and clogging the cabin filter or the outside of the heater core