RepairPal is your advocate for car care advice and guidance

Q: What is your opinion on using bar's leak to seal a leak in the heater core? on 2000 GMC Jimmy

Enthusiast 01be16a5a93688912f14755221fb15211b518d9a788cf01b455e03cc1bd585ac
I have an anti-freeze odor when I put heater on. Has been diagnost as a small leak in heater core.
No car image 94a1663db56199c5353592009e34aaa51078a2469bed068bb8d6f0ba43accf97
Get a Repair Estimate
Guaranteed by certified locations nationwide. Learn more
RepairPal estimates are guaranteed at over 1,700 quality certified locations nationwide. Learn more
There is a little chance it will hold permanently - if it holds at all.
These kind of additives has a tendency to create actually more cooling system problems.
I have seen many heater valves stuck, blocked coolant passages, etc..
Personally I'd never use stop-leaks in my cars because of the reasons above.

Replacing the heater core will in the long run be cheaper than using bars leak. Bar-leak will typically seal "holes" that are supposed to be there, like the actual tubes of the heater core the heater control valve, tubes in the radiator, passages in the intake manifold........ which will just make the eventual real repair cost more and more.
Didn't find what you were looking for?