radiator

[bucketmouth64]

I have a 93 dakota, 6cyl, with 370,000 miles. My heating is not very good. I had a new radiator installed 5-6 years ago. The last time I had service done (about year ago) to it I told my mechanic the heat wasn't getting hot so he replaced the thermostat with a chrysler part. Still problem exists. He says that my lower hose was not hot like the upper one which tells him that the fluid is not being circulated properly which is impairing the temperature. He recommeded a new radiator which is going to cost $400 to do. Vehicle is not overheating. Any ideas? Mechanic doesn't do a power back flush. I haven't found any mechanic that does this. Would this help? I would hate to get radiator replaced and not being the problem. Especially when it is relatively new.

[Jeremy airjer W]

I would start with flushing the heater core and then possibly thinking about the water pump.

[Shack]

If it is a partially or almost fully clogged heater core, Chrysler has a substance/chemical you can pour right into the heater core line before the heater core flush is done. I have also seen tech's use Drain “O” as substitution for the chemical. This chemical will run down into the heater core and fight the blockage, so during the flush more junk will release.

I would start by disconnecting both heater core hoses going into the plenum (heater box). Pour the chemical in both hoses (as much as you can and following any safety recommendations on can or bottle) and let it sit for proper amount of time. If using the Drain “O” I would say 20 minutes to a half hour tops (what ever it says on bottle to help unclog a drain). Locate the heater hose that was cooler than the other one, locate/find an adaptor nipple to fit in heater hose, that connects to garden hose on the other end and slip garden hose into the heater hose. Run garden hose at full volume (valve open all the way) for about 45 minutes to an hour. Watch the water coming out. If at first you get a ton of stuff out, I would plan on doing a second flush. Let water flush threw until water runs out clear and clean.

If you want to get creative, you could modify an air chuck/air hose fitting with a on and off ball valve to the fitting you made that adapts the garden hose to the heater hose. During the heater core flush, you could hook up an air line and inject low to moderate amounts of air pressure into heater core during the flsuh. This may help release any hard to get blockage.

This has worked well in the past with good strong heater cores. On a side note though, a week/rotten heater core could start to leak after using the strong chemicals or the air pressure. Basically exposing a future issues in your drive and not on the road.

If this does not work and due to the amount of miles, like Jer said above, the water pump impeller blades could be worn down to nubs and not circulating enough coolant to get hot coolant to the heater core or threw it, but yet pushing enough coolant threw main part of system and not causing over heating issues yet.

Good luck!