Leaking Coolant, Coolant Smell When Heat is On

I have a couple of problems with my 2000 2dr Jimmy (4wd, 4.3L, 113k miles).

First, it looks like I'll need to replace the intake gasket-again-after about 15k miles. I'm a little annoyed as I couldn't do this myself the first time around so will make sure this gets done right this time.

The real reason I started a thread, though, is because a little while after I noticed the intake leak again I started to smell coolant when I turned the heat on. After a little while running the heat the smell either disappears or I get used to it. No coolant smell when running straight air or A/C. Thinking heater core but hope not, which means it probably is.

The other problem showed up last night. I saw a small (6in diameter) spot of coolant near the front driver's side of my truck. I opened up the hood and removed the air filter assembly (not sure about it's real name) so I could take a look down that side of the engine compartment to see if I could tell where any leak might be coming from. Well, it looks like it's coming from the front of the radiator somewhere. There is an extremely small amount of coolant that looks like it's running down the ridges on the side of the radiator. It almost looks like it's coming from a bunch of different spots. When I look at the front of the radiator, (just through the grill), I see nothing. No wet spots at all.

My question on that is, what does this apparent, but unconfirmed location, leak mean for my radiator? Where could it be coming from?

Second, more jokingly, with all of these problems is my wallet screwed?

If it where the heater core you would smell it all the time. The smell is more than likely coming through the cowl from the engine compartment. Once you drive for a bit the smell clears out of the engine compartment and the cabin.

If the radiator is leaking out the seam, which it sounds like it is, than replace it. There are no fixes for this only band-aids!

If it was a heater core,it would steam up the windshield also.Put a pressure pump on and find the leak this way.

If it was a heater core,it would steam up the windshield also.Put a pressure pump on and find the leak this way.

Not always true. My heatercore leaked for 2 months with not a tiny bit of steam and this was even during the winter. Even the pressure tester did not help me here other than to tell me it was not able to hold pressure. I was fearful the heatercore was still good right up until I physically removed it from the truck and then I saw the leak.

IF you need intake gaskets, a rad and a heatercore all done at once your wallet is so screwed you are going to cry green. THe heatercore is a brutal job, basically everything you see in front of you when you sit in the seat will need to come off to access it.

The plastic radiator tanks are notorious for leaking on the frame side, (where it mounts to the front grill) just opposite of the upper radiator hose. In other words, where the Hot coolant hits the back of the plastic tank when it leaves the upper hose.

The radiator pressure tester can usually borrowed from your local Autozone for free. Pump up the Radiator when it is cool to the same pressure as the Radiator cap. You should be able to spot the leak easily. When My radiator started leaking, I had to loosen the radiator mount and move it away from the frame a little bit and the 3 inch long crack became plainly visible, and leaked like hell under pressure.

To buy yourself some time if you do have a leaking core, you can always buy a small plastic jumper for a couple of bucks that accommodates the two different sizes of heater hose and "jumper" them together by removing both hoses at the fire wall and using the clamps you just loosened to clamp the jumper in place. You won't have any heat, but it is Summer time and you can run this way until your wallet recoups.

I cannot stress enough that you absolutely do NOT want to put any sort of stop leak in the system. All that will do is cause even more problems and cost you more money in repairs. Stop leak is evil and should always be avoided at all costs.

Thanks for all of the replies.

I know for sure the radiator is leaking where Rick Norwood mentioned. Found it yesterday. Picking one up to deal with over the holiday. Surprisingly not as expensive as I thought. Any advice on that? Anything I should be aware of that might not be typical for this kind of job?

If the heater core is indeed bad, I'll wait until this fall/winter to deal with. I ran heat this morning and didn't smell a thing, but ran it last night and the smell wouldn't go away. It certainly doesn't seem like the typical symptoms that I've read about.

Thanks again.