Been smelling a mild coolant smell since we recently bought our 2014 JKUR (85K miles). Found the overflow hose was a bit loose on the radiator end with some coolant captured in the airbox ribs, so added a clamp. Still get the smell. No signs of leakage so far, and I know the overflow bottle is vented so maybe that's all it is. I know radiators, thermostat housings, and sometimes water pumps can be issues...

Anyway, I checked the coolant level and it is a tad low. Would like to add, and I know I'm supposed to use Mopar OAT, which I understand is reddish / purplish. Looking in the bottle, if anything it looks somewhat greenish, but there's not a lot there and the bottle is 8 years old. I know it can be bad to mix coolants, and since the Jeep's history is unknown to me I don't know for sure what's in there. I did pop the radiator cap and other than a very small amount of beige scum under the gasket area I didn't notice anything remarkable. The engine temp is normal and the heater seems to work fine thus far.

Would you:
a) top up with the correct OAT, figuring even if it is a mismatch it's only a few ounces anyway?
b) top up with distilled for now to buy a bit of time - figuring it is only a few ounces, and maybe plan on a full OAT coolant change in the next six months or something - once I see whether there's anything else going on?
c) some other option I've not thought of yet...

Thanks in advance!

 

I would top off with distilled water for the moment. Once things have cycled well I would pull the rad cap on a cool morning and suck some out with a turkey baster or something and into a clear bottle. OAT is kinda orange'ish with a purple additive. In a clear bottle it will look purple, but if you just open the rad cap and look in it will appear a rusty orange.

A common leak area is the radiator where the fins meet the plastic side....typically driver's side and typically you don't see any sign cuz it burns off so fast and the radiator shroud is in the way. It takes maybe 5-10 minutes to pull the airbox and intake boot and the fan shroud to get a good look at the back side of the radiator if you care to. Post #24 in this thread is a pic of an old one of mine. That radiator never showed any sign of a leak when inspecting from down below. A drop never made it that low.

https://www.jk-forum.com/forums/stoc...6/#post4319572

**Never had an overheating issue. From time to time I would just get a whiff of coolant and about every 2-3 weeks I'd notice my resi level was low by a couple cups.

 

Buy the type that says it is compatible with all kinds.. Been doing this for years. I use to worry that it was going to gel up or some crap. Nah.. I watched a video put out by the coolant companies saying to stop worrying about the color and find one that says it will work with all kinds. Its that simple.

 

I agree with resharp; just add distilled water for now and figure out whether you have a leak or not. Depending on where the leak is, you might wind up doing a flush anyway. If so, then the next decision is whether to replace the radiator hoses, now that they're 8 years old (I've had 2 failures in 10 years).

 

Thanks everyone - I appreciate all of the input. Added distilled this morning and will do some more investigating for the suspected leak. Utimately I think I will plan a full flush just so I have a "zero" benchmark in terms of what's in there, the concentration, and how old it is.

 

So back here after a year or so... My Jeep doesn't get a lot of miles since I have a really short commute, and the coolant loss rate never increased. But it still bugged me. Finally today I dug into things. In addition to the possible radiator seepage mentioned above, I had also read online about overflow bottles cracking & seeping, as well as the thermostat housing failing.

So, to cut to the chase, in my case it is the thermostat housing. Just a bit of residue on the front of it, almost unnoticeable. But I used a mirror to check the underside and much more evidence there of seeping & evaporation. I did check my overflow bottle and radiator - no signs of leakage on either one.

I will be buying a new OEM Mopar housing, and a new thermostat and changing all of the coolant that I can. Looking for opinions on a couple of points:

• Should I get a genuine Mopar stat? I've read about folks playing with the opening temp. What degree should I go for?
• Jeep is now 10 years old with about 91K miles. Should I change all of the hoses (radiator, heater, etc.)? They all feel a bit spongy, but I don't know what is normal with Jeeps. If I do change 'em, is there a preferred brand?
• Flushing? I am pretty sure someone put some sort of stop-leak in at some point - the overflow bottle and inside the rad cap have a brownish greasy film. Should I look into any sort of more aggressive commercial flushing or chemicals?
• Does anybody know how much coolant is left in the system after one pulls the stat and all the hoses? This may help me know whether to just go with a universal coolant depending on how complete the draining is.
• Is there anything else I'm missing?

Sorry for the long list, but I like to be prepared and want to do this once and do it right. I'm gonna keep reading threads - feel free to point me if there'a a good comprehensive info repository somewhere.

Thanks in advance!

 

I would stick with a Mopar thermostat. The housing and the thermostat come as 1 piece. I'd also stick with just Mopar OAT, but that is me and I get paranoid about getting every single bit flushed out of the block and heater core. I'd rather error on the side of caution and stick with what has been in there, assuming you know it's Mopar OAT. At my dealer a gallon of concentrate is ~$23.50, not much more than the good Zerex I use in some of our other vehicles. My jeep is '13 with 118k miles and I still feel just fine with my factory hoses. Given your mileage I don't think it's a big deal. If you had 150k+ I'd say those things have lived in a lot of heat over that same time period. That is just my 2c.

 

Thanks for the reply... Yeah, I don't really know what's in there, other than it smells like coolant. The stuff in the overflow is a light brown, but that's probably because I had to temporarily add some distilled again. I think I will follow the process here (https://www.jk-forum.com/how-tos/a/j...coolant-407878) using OAT concentrate. Possibly adding some chemical flush. I took a look at the location for the radiator petc0ck - holy crap that's inaccessible and what a tiny drain! This should be fun... and take a good chunk of a day.

 

Y, that petc0ck is worthless. Just pull the lower hose and let it gush out. You can also pull the thermostat, rip the old one out of the housing and put the housing back on and then pour distilled back through the block. I've not worried about the heater core before. I just rebuilt the timing on my jeep so everything came off the timing cover, and in the process I was surprised how difficult it was to get the lines to/from the HC off the timing cover. If you chose to mess with that then I'd think it would be easiest to disconnect there at the firewall. I'd likely feel fine leaving that coolant in there though cuz it's not all that much, especially if what is draining out looks like OAT.

 

OLD THREAD, but sibject in the line of my issue...
changed my fluid by a thourough flushing, original collant had a continuous odor, which i wid not like.
changed my rad.
this new collant is yellow and mix it with distilled water.
aftre many years of driving, i noticed that color is now brownish!!!
i do not seem to have a leak, the odor is completely gone.
what can cause this colow change? old system tubing? any thoghts? comments?