I have a issue with my wifes E150. There seems to be a varying amount of coolant smell coming from the HVAC vents. The catch is, the heater core was replaced couple years ago and my mechanic just did a pressure test on the cooling system and it passed with flying colors. He thinks it's just residue from the old heater core but the smell persist and the wife is not happy.

Any ideas guys?

 

Well if it is tested and OK , the mechanic is right ...you could put some Febreeze vent clip deals till it goes away....

 

Smell should be gone after that much time . If I remember correctly those heater cores are simple to change . You could remove the access panel and ck for coolant in the housing . It could have a small leak when warm or cold . Not enough to "leak " but enough to smell .

 

By the way , I put 3 !!! heater cores in a 98 F150 in ONE YEAR ! The parts house told me they had a bad run of parts ! Had a lot come back .An 8 hour job ! The 3rd one came from Ford .

 

I can't imagine a situation where you would be smelling coolant years after a heater core replacement. That just doesn't make any sense to me. If you can smell it there is a leak somewhere. Was the coolant maintained? Heater cores generally don't go bad on their own, typically they are a consequence of lack of maintenance because the corrosion inhibitors in coolant will wear out over time.

So it stands to reason that if your heater core failed because of this other components aren't far behind. Just my two cents.

 

Radiator was done last year. HC, two years ago. I'd like to do the water pump soon. The coolant was changed with the radiator.

I just don't understand how the thing can pass a pressure test and have a leak. They said they tested it for 2 hours.

Also my wife noticed that when when turned the HVAC off completely today the coolant smell actually got worse, which makes no sense to me.

 

Doesn't make sense to me either, but your van has a history of coolant problems. Sounds to me like the coolant was neglected and caused all sorts of mayhem, so another leak doesn't seem out of the question to me at all. The coolant smell doesn't just come from nowhere!

 

Coolant turns acidic and eats things . Do test on your coolant system for electric bleed, improper ground or conductive coolant . That can eat cooling system parts .

 

On my 94 the heater core failed and after replacement I was still getting a faint oder of coolant. One of the hose clamps loosened slightly allowing a small leak into the plenum. I also replaced the heater hose since it was original. Some leaks won't show unless the engine is operating temp.
Regards
rikard

 

A few things come to my mind about the HC, having changed my own a few times on the E Vans............

Its possible there is a leak outside the cabin that quickly finds its way inside and to your wife's nose. Women tend to be more aware of odors due their enhanced olfactory senses so that also might be at play here.

That this smell is more evident after HVAC is off completely is a bit puzzling to me too. Hot coolant constantly circulates through the HC with engine running, if there is a leak inside the cabin in theory its odor should be more evident with the blower turning, even on its slowest or the speed switch set to off.

If you're a handy DIY the outer HC box cover is somewhat easily removed. Once off there would be evidence of a leak, perhaps a few drops or small pool of coolant collecting there.

Hoses could also be an issue given the age of your E150. The quick connector hose connectors tend to remain intact unless they weren't inspected during the HC's replacement, Replaceable lock bushings might need inspecting as its possible they're causing a small leak and in turn this odor.

Something like this would scare the dickens out of me---wondering how long 'til something inside bursts and I'm in a glycol steam bath at 65 MPH!

Let us know your progress or updates please---will be interesting to follow up.


HTH

 

I have a similar situation in an E450 and from what I've read in several posts, I'm leaning towards a leaky heater core. My question is, can the odor mimic that of a dead animal?

 

Good morning hbridge, and welcome to FTE!

Nope, I don't see that happening. Coolant has a unique sweet smell to it. If you smell dead animal that may be your problem.

 

Tom, thanks for the welcome note. I've pulled everything apart looking for an animal, or some parts of one, without success. Our authorized Ford mechanic first told me that the coolant was "burnt" then came back with "PH was off". Any thoughts on that comment? Also, when we initially discovered what we thought was the source and opened the coolant resevoir, the smell from the tank was overpowerning and the color of the coolant was very dark. If I have oil and coolant mixing, could that cause this odor which seems to increase with driving distance. The truck has about 16K miles. Thanks for your input.

 

"Burnt" coolant or if tested and the pH is off that's troubling all by itself. pH when out of spec for the coolant means something has changed its chemical make up, quite possibly shifting towards acidic, a very bad situation indeed.

From your description and assuming you're not having overheating issues my guess is the trans cooler inside the radiator has sprung a leak letting AFT flow into the coolant. This needs to be addressed ASAP otherwise repair bills will be much higher than a new radiator. Check the transmission dipstick for any signs of coolant having mixed in.

Testing the radiator for leaks might not show the internal trans cooler is leaking so its possible to have positive results but a problem still existing.

Another WAG would be the oil filter mounting boss with integrated coolant loop could be leaking too. That would be rare but not impossible.

And just because something is fairly new or recently replaced doesn't mean much if the installation is at fault or parts used have failed.

 

I've never heard of ATF causing a foul-smelling coolant reservoir, but I can certainly imagine combustion gasses doing the same. Has the van overheated in recent history? A bad head gasket could be causing this.