Cabin coolant smell but levels remaining stable...?
 

Hi there, I've searched several variations of key words but haven't found anything like this.

My 99 Jimmy will smell like coolant in the cabin with the heat on or off as it starts to warm up. There is no wet floor, foggy windows, etc... no leaks/puddles under the truck, and I've kept an eye on the coolant and cant really tell that's it even lost anything. Very little if at all.

What the heck could it be? Heater core leaking somewhere else? Some kind of leak in the engine that's being vaporized once the engine heats up? I know the water pump was recently replaced, but that is about it.

I guess I'm mainly curious if there are common problem areas to check out or if anyone has some specific places to check. I'm not a big fan of stop leak products and definitely dont want to use one if it's not even a heater core leak.

Thanks!

Try flushing the heater core... Not saying it will fix the problem but it is a very cheap start...

I am asking sincerely because I truly do not know... but would flushing a heater core help with the smell of antifreeze

Heater core seeping. The only place where the coolant is inside the cabin is in the heater core. Doesn't take much to stink. You'll be finding out pretty soon I suspect. Or you can flush it and find out for certain even sooner! Not a lot of fun to fix.

I kinda had the same problem with the smell of coolant in the dash board area... I never seen any kind of leak, just a sloshing liquid kinda sound... I flushed the heater core and the sound and smell went away. It also made the defrost and heat work 5 times better or more.

Years ago I mistakenly indicted my heater core due to a slight coolant smell in the cabin with no wet carpet or fogging windshield. I bypassed the core through the summer but occasionally still had the smell. Turned out to be the dreaded LIM gaskets and that repair cleared up the coolant in the oil and the coolant smell in the cabin

George

Thanks for the reply. I have heard about the intake manifold repair... luckily this is only my winter beater. The oil was changed religiously by the previous owner who has experience working with vehicles (and is a family member), I am sure he would have noticed coolant in the oil and I haven't seen or smelled any on the dipstick so I am hopeful I'm still good in that regard.

as mentioned though it doesnt seem like my coolant level is even going down... it's been since Thanksgiving, so... 3-4 weeks and it still appears to be at the same level in the reserve tank and the radiator is full. Really strange.

I am afraid of flushing it and then having a complete failure of the core, lol... like if its barely hanging on right now due to the soot in it. Maybe I will do that this spring when I pull my main vehicle out.

the smell seems to dissipate after a little while which is also strange, and as mentioned the coolant levels have hardly changed over the past month of driving.

it also has apparently been this way for a very long time. I think it's easy to ignore because the smell dissipates after about 5-10 minutes. Maybe that is just scent blindness taking place, I dunno. It does go away though. I know those fumes aren't good for you though so I am just trying to track it down. The truck doesnt have a cabin air filter that I know of, so I dont see why the scent couldn't be coming from the engine bay somewhere, although there isnt a coolant smell from outside the cabin.