Possible coolant leak?

Ok, here's the deal: My 94 Bravada runs perfect, perhaps a little too perfect. It starts right up, all the electrics work, it gets decent mileage. However, one day when I was letting it warm up, I happened to glance down at the very bottom of the dash, in the middle where it joins the carpet, and I notoced a very fine, drop of coolant running down the dash. I wiped it up, and watched for 5 more minutes to make sure no more came out. I then opened the hood, and could find no leak what so ever. I looked under the car, and found nothing dripping. That was three days ago, and I haven't noticed it since, but I am a little worried.

you have the dreaded heater core leak. the heater core is a small version of a radiator located behind the dashboard on the passenger side used to provide heat to the cabin when needed. the part doesn't cost much but it's a bear to replace. in the short term you can disconnect the hoses running to the heater core and run them back into each other, bypassing the leaking core, but you'll have to replace it eventualy.

antifreeze leaks can be more dangerous than you think. we had a small heater core leak that went unnoticed until we went on a long road trip. about three hours into the trip my wife, who was sitting in the passanger seat with the windows rolled up, had a grand mal seizure. very scary. and she has a cdl so she automaticaly lost her job for 6 months and can't drive any vehicle for 6 months.

common anti-freeze is a veritable soup of toxic chemicals, although up to now i've never experienced any problems even though i've changed three cores and a couple of radiator hoses in the past two years on my vehicles. we think it was the duration of exposure combined with lack of ventilation, or worse her sole source of ventilation was thru the saturated ventilation system. The link to a poison center sheet on one of the worst componets of anti-freeze is http://www.iowapoison.com/index.asp?pageID=155

yeah, I figured that, but I just figured since my coolant levels have gone down, and my car had been on a uphill slope for a couple days that I had a pinhole leak in a hose or the reservoir or something.

I guess I'll have to try running the heater, but the last time I ran it, in July, it was working fine, no smells. I know the A/C works great, no smells or sounds, but we'll see.

okay, I ran the heater, and no leaking, weird sounds, or odd smells. Just a nice even warm air. Howver, I did reach up under the bottom dash cover and felt around and finally felt just a thin trickle of coolant. Would a coolant leak stopper fix this?

bump

i've never had much luck with the stop leak additives. IMHO you need to either replace the heater core or bypass it. also take off the passenger side kick panel and the plastic carpet strip by the door and check under the carpet for coolant pooling and saturated heat insulation. it's only about six or eight screws.

check on this forum for an old posting called "pond in my bravada" or just search for the word "pond"

yeah, I noticed that it only had a few screws, I'll probably take that off today and get a better look at it. I just figured since it seems to be such a little leak that it would be a good idea to try an additive. Another plus, is that it seems to have been doing this since I bought it over a year ago, which gives me hope because I've been using the heater sparingly over the year, and nothing has happened. The reason I know is because I noticed some slight discoloration in the passenger side carpet when I bought it, just little drops here and there. But i put in carpet covers to cover those up, and so far no more spots.

i don't know about the '94's but my 92 heater core has coolant running thru it all the time, wether you are using it or not.

I wonder if doing the old radiator egg trick would work.

I haven't gotten around to removing that cover, but I hvae been checking out some radiator and heater core leak stoppers, and the reviews for Alumaseal seem good. Plus a few sites about cheap tricks to avoid repairs suggest that as a long-term repair.

you can try the stop leak but thats not really a permanent fix. to fix the problem right you have to spend a whole $40 for a new core and quit wasting time posting on here and get it done and over with.

the reason I'm looking for other solutions is because #1, I won't be driving this vehicle much because of rising gas prices, and #2: I hear that it can take as long as 10 hours for a heater core to be replaced, so I don't really feel like spending that much money on labor.

I replaced mine in a coupla hours the second time on my '92.

when using Bar's Leaks for a heater core leak, do you have to have the heater on?

Nope, the heater core gets water all the time the motor runs. Another option is to take the heater hoses off the motor and connect a single hose on the motor water outlets...until cold weather arrives.

well, what I meant was when adding Bar's Leaks to the radiator system, do you have to have the heater on for it to properly stop the leak.

more good news is I removed the cover and some other parts of the lower dash, and have verified a small pinhole leak in the heater core. So, because I have had these coolant spots on the carpet since I bought the car, I believe the dealer used a leak stop to disguise the issue. I'll do the same thing untill I get around to buying a new heater core and replacing the old one.

well, the stop leak worked, but I won't go for too long without buying a new heater core.

Very good. You also know how to get the heater core out to replace it later. Now if we could just find someone who builds a really reliable heater core with enough brass to last more than a coupla years...venders, are you listening?

Very good. You also know how to get the heater core out to replace it later. Now if we could just find someone who builds a really reliable heater core with enough brass to last more than a coupla years...venders, are you listening?



Amen to that, Chris. And fuel pumps. I've had to change both of them out on 3 of my GM's. The only one that is still origional is on my 1950 gmc half ton, 55 years and still going strong so I know it can be done.

A word of warning Toolwise, be sure to check for antifreeze under your carpets and in the heat insulation under the carpet. It will off gas and coat your interior and windows with a greasy film. Just flush it with lots of water and maybe some Dawn dish soap and suck it out with a shop vac.