Should I run some coolant sealer in my xj?

So, my heater core must be leaking a bit, because I still have a smell inside on the passenger side. I have seen some sealers at the auto parts store, but not sure if I should use it. I did replace all the hoses, water pump and valve about 30,000 miles ago, so I don't want to damage those.

I have always thought you should fix the problem right, but the heater core looks to be a pain to replace.

Anyone have any experience with coolant additives???????

Thanks,
RG

I have seen very "mixed" results with stop leak products but I wouldn't recommend using a sealer for a heater core leak. Haven't heard many success stories for sealing leaks on that component. And yes, the heater core is a major PITA to replace! Could you do the work yourself? Not really that hard for the do it yourselfer, but does take quite a long time, especially if you haven't replaced one before. If you take it to a shop, you'll be nailed pretty hard with labor; the part is cheap.

http://www.naxja.org/forum/showthrea...ghlight=heater Search:Heater Core. (Magimerlin) Post-a-Write-Up Thread (one you made or one you used) by Hammered ,1 day ago

Maybe helpfull.:yelclap:

I used a stop-leak block-sealer type product on my son's grand cherokee, and it worked fine. His heater core was constantly fogging the wind-shield. You need to find the kind that is compatable with the anti-freeze, so you can just add it and forget it. I found it at NAPA.

The fiber pellet type is OEM at some factories on new cars (which explains why millions of new cars never leak.) I have used them, they work.

I have also put off the repair too long. As said, the core is cheap, $30-$50, but you have to remove most of the dash. Big phillips screwdriver job these days, a lot worse in the sixties when cars like my Mustang had a metal dash welded in. It's not really hard - just tedious with multiple layers of assemblies. You do need a good exploded diagram to find all the hidden screws - or a bunch of superglue and duct tape . . .

Thanks for the replies.

Not sure what type of stop leak using pellets?

No one is saying anything bad about this stuff, so I guess it would not hurt my cooling system.

Any other information would be greatly appreciated,

Bob

After many years of swearing that I would never use the stuff and ragging on those that had, I broke down and used some of the Bars Radiator Stop Leak that had the pellets in it. I had a pin hole leak in my radiator that had gotten bigger and I was adding coolant every morning. With the outside temp in the single digits, I gave it a try. It seems to have done it's job, and I have not yet had any problems with a clogged heater core. I plan on replacing the radiator once the weather warms up, but as a temporary fix it seems ok. Just be sure to follow the directions and idle or drive the jeep for a 1/2 hour after adding the stuff. also, you might have to drain off some antifreeze to get the entire bottle in there.

I'm not a big fan of sealers but have to admit that they do work in certain situations.
From the posts I've read and other information/recommendations about this product, Bars Leak is the one that is mentioned the most.

The heater core is a pain to replace.

I'm always wary of using a cooling system sealer. The stuff is designed to do what - find a hole and harden, thus patching it from the inside.

Theoretically, it doesn't harden until it gets contact with air (aerobic action,) meaning it should not harden in your system.

Aerobic reactions are typically air-catalysed, meaning that it starts to run itself for a bit after it gets started. This is why RTV (an aerobic sealant) cures all the way through.

What's to stop this stuff from doing the same thing, then you end up with a patch that has less effective heat transfer than the base metal. Could be a problem if you have a pinhole in your radiator core as well, and most of it goes there.

Yes, I know it's a pain. Heater cores are always a pain, on pretty much any vehicle. It's still better all around to do it (not only does the sealer have the potential problem above, but odds are good that was just the spot that "wore through first.")