[mike78nc]

Hey guys. Hope everyone is doing well. So I have been doing some reading on old posts regarding coolant smell and have done some investigating. Car is a 2015 Challenger Hellcat. The car has a little over 30,000 miles. I smell coolant from the front of the car when it’s at driving temps. I have been under the car looking for leaks and can’t find anything. Doesn’t seem to be losing coolant as far as I can tell. I also used a pressure tester and pumped the system up to about 16 psi and it didn’t lose pressure. Maybe I am being over cautious I dont know. I’m nervous to drive the car right now because I don’t want to mess anything up. I drove the car about 35 miles the other day and it even looked like there was some steam coming from the drivers side vent on the hood. This is when I began investigating. Could it just be the cap on the coolant tank? I was going to replace that and see if it went away. That would be great if that was the problem. I know there are older threads on this, which I have read. Just wanted to see if there was any new information on this or if this is still an issue on newer cars. I appreciate the help. Thanks.
Mike

 

[104148]

Best way to find out is have the cooling system pressure tested. Or you can buy a pressure tester for $100 or so.

 

[mike78nc]

Best way to find out is have the cooling system pressure tested. Or you can buy a pressure tester for $100 or so.

I bought a pressure tester and hooked it up. Didn’t lose any pressure and couldn’t find any sign of a leak.

 

[Hellcat Forester]

Look for any seepage around water pump. Sometimes when they go bad you’ll smell it but no noticeable drips.

 

[mike78nc]

Look for any seepage around water pump. Sometimes when they go bad you’ll smell it but no noticeable drips.

I’ll check it out. Thanks for the help.

 

[Linda's Hell Cat]

Does your HC have any mods done to it?

Linda

 

[mike78nc]

Does your HC have any mods done to it?

Linda

None that I’m aware of. I just recently bought the car used. Appears to be stock.

 

[Mopar23]

Could be thermostat related

 

[Linda's Hell Cat]

Could be thermostat related

I was thinking the same thing.
There were guys who changed the stock to the 180 T stat.
No tune or mods. I can't find the thread on it, but it was pretty long.
I'm not sure why they did, probably depended on where they lived.

Linda

 

[mike78nc]

I was thinking the same thing.
There were guys who changed the stock to the 180 T stat.
No tune or mods. I can't find the thread on it, but it was pretty long.
I'm not sure why they did, probably depended on where they lived.

Linda

I appreciate all the help. I was reading a post last night where someone stated that the stock thermostat was important for this car. He/she stated that the higher temps resulted in less cylinder wear and a few other things. I dont know if I can find the post again. I have been doing a lot of reading. How do you feel about that? I know a lot of folks switch to the 180 degree thermostat. I just want to have the best quality of life I can. I bought the car used. I’m sure it’s been beat on a fair bit with 30,000 miles on it. I’m sure these engines are pretty tough and can take a fair bit of abuse. I don’t have a warranty of course and I plan to do any work on the car myself unless it’s not possible or I’m in over my head. I’m by no means a mechanic or anywhere close to it. I’ve been into different engines and I’ve built some small block Chevys. I just enjoy learning and wrenching on my own cars if I can. I don’t have much time nowadays with a 1 year old so it takes me some time to get things done. I’m dying to drive the car as I haven’t had it long but I hate to drive it with the coolant smell because I don’t want to wreck the engine over something that’s hopefully a simple fix. Thanks for all the advice.

 

[why2kmax]

Hey guys. Hope everyone is doing well. So I have been doing some reading on old posts regarding coolant smell and have done some investigating. Car is a 2015 Challenger Hellcat. The car has a little over 30,000 miles. I smell coolant from the front of the car when it’s at driving temps. I have been under the car looking for leaks and can’t find anything. Doesn’t seem to be losing coolant as far as I can tell. I also used a pressure tester and pumped the system up to about 16 psi and it didn’t lose pressure. Maybe I am being over cautious I dont know. I’m nervous to drive the car right now because I don’t want to mess anything up. I drove the car about 35 miles the other day and it even looked like there was some steam coming from the drivers side vent on the hood. This is when I began investigating. Could it just be the cap on the coolant tank? I was going to replace that and see if it went away. That would be great if that was the problem. I know there are older threads on this, which I have read. Just wanted to see if there was any new information on this or if this is still an issue on newer cars. I appreciate the help. Thanks.
Mike

My 15 did the same thing around 20k. I could always smell it in traffic and when Id shut it down and get out of the dar, but I could never find the leak. Explained it to a Dodge Tech (not service writer) during an oil change and he let it run for 30-40 min until he found it. The radiator had a small crack and it was dripping down on the lines and evaporating before it hit the ground or was visible under the car. The radiator was replaced under warranty.

 

[mike78nc]

My 15 did the same thing around 20k. I could always smell it in traffic and when Id shut it down and get out of the dar, but I could never find the leak. Explained it to a Dodge Tech (not service writer) during an oil change and he let it run for 30-40 min until he found it. The radiator had a small crack and it was dripping down on the lines and evaporating before it hit the ground or was visible under the car. The radiator was replaced under warranty.

I’d honestly be thrilled if it were the radiator. Reading all the posts about head gaskets, milling, and supercharger leaks is what I’m worried about. I feel like I could replace the radiator. I think I’m going to pump it back up with the pressure tester and let it sit for awhile. I didn’t let it sit very long last time. Tough to find a leak on this car. So many coolant lines and it’s tight in the engine bay.

 

[Spoolin]

I’d honestly be thrilled if it were the radiator. Reading all the posts about head gaskets, milling, and supercharger leaks is what I’m worried about. I feel like I could replace the radiator. I think I’m going to pump it back up with the pressure tester and let it sit for awhile. I didn’t let it sit very long last time. Tough to find a leak on this car. So many coolant lines and it’s tight in the engine bay.

That a good idea. Pressure it up and let it set for about 30 minutes to see if you can spot any odd things.

 

[Linda's Hell Cat]

Maybe this will help.

2015 Challenger Hellcat Radiator TSB

I’ve have looked and have seen a few discussions on this but can’t find the actual TSB from Dodge on the radiator feeler gauge one . Can anyone help I have a weeping radiator !! Also can anyone recommend a good aftermarket radiator ??

www.hellcat.org

 

[mike78nc]

Maybe this will help.

2015 Challenger Hellcat Radiator TSB

I’ve have looked and have seen a few discussions on this but can’t find the actual TSB from Dodge on the radiator feeler gauge one . Can anyone help I have a weeping radiator !! Also can anyone recommend a good aftermarket radiator ??

www.hellcat.org

I did check the upper radiator hose and it does have two clamps on it so I guess it was taken in by a previous owner for that. As far as the radiator, wouldn’t I see leaking somewhere? Or loss of pressure? I have had my pressure tester hooked up to the car for the last 4 hours and it hasn’t lost pressure at all so far and still no leaks as far as I can tell. It would be nice if it was just the cap. I am thinking about purchasing a new cap and trying that to see if the smell subsides. I see that many performance sites sell caps but I’m not seeing any that are 21 psi like the factory. Is it ok to go with a lower psi rating?

 

[Linda's Hell Cat]

Some more info from another thread.

[QUOTE="Rockster,
The odor of antifreeze when the engine/cooling system is hot is almost certainly because of a leak.

Had one car that on a hot day I smelled anti-freeze. Got car into dealer service and tech put car on lift and very clearly at the water pump there was coolant leak sign, and sign it had been leaking there for some time. I'm pretty good about looking for any signs of a leak under my cars when I walk up to them and I never saw any leak sign on the ground under the car.

Yet, this same car "fooled" me when after I had the radiators replaced upon using the car -- essentially giving it a shake down test drive before heading out on a 2K mile drive back home -- I smelled anti-freeze. Took the car back to the dealer service department. Tech checked over the car and reported no leaks. He did admit he spilled some coolant when refilling the system. He rinsed the engine thoroughly and started the engine and got it to temperature and there was no smell. I took the car and after some more shake down testing deemed the car ok and drove it home with no problems.

My advice is do a hot pressure test.

With the engine dead cold top up the coolant level using distilled water. Do not over fill the cooling system but bring the level up closer to the max line. The less air space in the system the better.

Be sure the cap is on properly.

Turn off the A/C.

Drive car around town -- my experience this gets the engine -- coolant and oil -- hotter quicker and just hotter than a drive at freeway speeds -- until the radiator fan comes on due to the coolant temperature reaching the fan on trigger temperature. With my Hellcat this appeared to be 216F.

Go home.

On your driveway raise RPMs to ~1K and hold until the radiator fan comes on. When it does shut off engine.

Raise hood.

Wait.

The heat load of the engine will raise coolant temperature and pressure and if there is a leak almost certainly you'll know it.

Most likely the leak will be from the water pump seals, but I had one car with a coolant tank that had developed a crack along the bottom of the plastic tank at the mold seam.

Another time the coolant tank cap proved to be defective. It allowed pressure to escape at too low a pressure. With this leak I did not smell anti-freeze because only water vapor escaped. But I did spot some drops of water on the trunk lid above the coolant cap. I tented the cap with aluminum foil and after a few minutes after I shut off the hot engine water had condensed under the foil. A new cap put a stop to that.

 

[mike78nc]

Some more info from another thread.

[QUOTE="Rockster,
The odor of antifreeze when the engine/cooling system is hot is almost certainly because of a leak.

Had one car that on a hot day I smelled anti-freeze. Got car into dealer service and tech put car on lift and very clearly at the water pump there was coolant leak sign, and sign it had been leaking there for some time. I'm pretty good about looking for any signs of a leak under my cars when I walk up to them and I never saw any leak sign on the ground under the car.

Yet, this same car "fooled" me when after I had the radiators replaced upon using the car -- essentially giving it a shake down test drive before heading out on a 2K mile drive back home -- I smelled anti-freeze. Took the car back to the dealer service department. Tech checked over the car and reported no leaks. He did admit he spilled some coolant when refilling the system. He rinsed the engine thoroughly and started the engine and got it to temperature and there was no smell. I took the car and after some more shake down testing deemed the car ok and drove it home with no problems.

My advice is do a hot pressure test.

With the engine dead cold top up the coolant level using distilled water. Do not over fill the cooling system but bring the level up closer to the max line. The less air space in the system the better.

Be sure the cap is on properly.

Turn off the A/C.

Drive car around town -- my experience this gets the engine -- coolant and oil -- hotter quicker and just hotter than a drive at freeway speeds -- until the radiator fan comes on due to the coolant temperature reaching the fan on trigger temperature. With my Hellcat this appeared to be 216F.

Go home.

On your driveway raise RPMs to ~1K and hold until the radiator fan comes on. When it does shut off engine.

Raise hood.

Wait.

The heat load of the engine will raise coolant temperature and pressure and if there is a leak almost certainly you'll know it.

Most likely the leak will be from the water pump seals, but I had one car with a coolant tank that had developed a crack along the bottom of the plastic tank at the mold seam.

Another time the coolant tank cap proved to be defective. It allowed pressure to escape at too low a pressure. With this leak I did not smell anti-freeze because only water vapor escaped. But I did spot some drops of water on the trunk lid above the coolant cap. I tented the cap with aluminum foil and after a few minutes after I shut off the hot engine water had condensed under the foil. A new cap put a stop to that.

Awesome. Thank you. I’ll definitely give this a shot when I can. Probably be next week sometime before I can. I have been hesitant to drive the car in the event that it was a head or blower issue.

 

[Chancey]

I have another thread on here that I posted on concerning the exact same issue. I had a 2020 redeye that always smelled like coolant/antifreeze after obtaining operating temp. Never lost coolant, never dripped a single drop on the ground. I traded it for my new 2021 SS. Then at about 4000 miles, it too smells of coolant after getting up to operating temps. Same thing, never leaks (that you can find), never loses coolant, and never overheats. Even when 90 degrees, in traffic, with AC on. Zero noticeable issues. On the 20 redeye, dealer supposedly pressure tested it for 30 minutes and declared no leak. Even though everyone could smell antifreeze. I am gonna bite the bullet and buy a pressure tester, pull all of the belly pan plastics off underneath and fine tooth comb the whole setup. Like on the 20 redeye, doesn’t seem to hurt anything or lose coolant, just bugs the crap out of me!

 

[SRyeeT392]

check your coolant tank reservoir cap. I did the pressure test too and it was as all good, so it was just vapor leaking past the bad cap. I swapped in a new cap and all good

 

[Dennis H]

I have heard that this hard to find odor is weepage. I would put K-Seal in. Read directions and research for yourself.