96 s10 heater core

The third heater core just ruptured in 5 months. I suppose there is some kind of electrolysis at work here. Are there any common causes for this in a 96 2.2l s10?

Antifreeze???..this will keep the corosion in check. How often do you change it???

Suggest change of antifreze, and cooling sytem flush if you have not already done so. But avoid the GM DEX COOL long life; it becomes very corrosive when mixed with air. I use the old style green stuff and change it every 40,000 miles or so.

Check to make sure that something like the heater fan, is not grounding out via the heater core.

I agree about the antifreeze. You also may need a newer radiator cap, it may be creating too much pressure. I would also want to check to make sure the temperature is not going high.

I first changed it @ 80k useing dex cool and again @ 157k when the first heater core failed. I also flushed it @ this time. When the second failed in about 30 days I drained an refilled it again w/ dex cool and replaced radiator cap.

I did replace radiator cap when the second core failed along w/ the thermostat. I have had the dash out twice(cut 2 hours off the 1st time) and both blower and core seem incased in plastic. I don’t readily see how one can short to the other. Should I just follow the wireing diagram for the blower to check for improper grounding?

After 237,000 miles i guess the heater core on my 87 Ranger was entitled to spring a leak.

My brother in law owns an auto parts store. Told him I wanted a made in USA core, not some cheap imported crap.

For 17 bucks he got me a 4 seasons/made in USA core.

In big bold letters the instructions that came with the core tells me the following:

Caution: Electrolysis can cause rapid heater core failure.

“Electrolysis is the transfer of metals in a cooling system caused by either ionized coolant or incorrect engine grounds. The electricity flowing thru the coolant can cause pinholes to form in the heater core & or radiator. Proper servicing of the coolant, and correct instalation of the engine grounds should eliminate electrolysis.”

If you have a set of wiring diagrams that are worth the paper they are printed on, they will tell you the location of all the engine compartment grounds.

Check them for clean tight connections.