Reader Question: On my 1991 Ford Explorer 4.0L driver’s side head on the front-end of the head there is a small crack midway vertically between the top and bottom of the head.
The coolant leak is external. What do you recommend for a stop leak sealer? While the amount of leakage is small and slow, it is continually seeping/dribbling while the engine is running.
I have read your suggestions about leaving the sealer in for 500-1000 miles before draining, flushing and refilling with coolant mix.
Thanks for you help.
If this is a coolant leak I would try the K&W engine block sealer additive.
It will probably work perfectly in this situation.
Here is the article again with my instructions: