[Jenapher928]

Hello everyone. I have a 2017 challenger hellcat. I’ve had it for a few months. No issues. Out of nowhere. It started idling warm. Around 221. The temp gauge jumps up and down like something is sticking. You can also smell the smell of overheat. Checked the coolant and the overflow was low so I put more in. Even got a coolant flush. Didn’t help. The reservoir was super dirty so I bought a new one and installed today. I thought maybe a pin hole leak from that but no. It still smells like overheat. Oh and I took it to the dealership. They put 20 pounds of pressure and they couldn’t find any leaks. They don’t see anything wrong. No codes. And they said no leaks. But when I did change the overflow tank. There was no coolant in there so it must be leaking somewhere. Anyone with the same problem?

 

[Blickie]

Hello everyone. I have a 2017 challenger hellcat. I’ve had it for a few months. No issues. Out of nowhere. It started idling warm. Around 221. The temp gauge jumps up and down like something is sticking. You can also smell the smell of overheat. Checked the coolant and the overflow was low so I put more in. Even got a coolant flush. Didn’t help. The reservoir was super dirty so I bought a new one and installed today. I thought maybe a pin hole leak from that but no. It still smells like overheat. Oh and I took it to the dealership. They put 20 pounds of pressure and they couldn’t find any leaks. They don’t see anything wrong. No codes. And they said no leaks. But when I did change the overflow tank. There was no coolant in there so it must be leaking somewhere. Anyone with the same problem?

Was the 20 psi pressure test done when the engine was cold & not running? It needs to be done @ operating temp.

Did the original tank have an oil residue in the tank & on the bottom of the cap?

 

[Jenapher928]

Was the 20 psi pressure test done when the engine was cold & not running? It needs to be done @ operating temp.

Did the original tank have an oil residue in the tank & on the bottom of the cap?

I’m not sure. The dealership was a joke. They said. We did all the test. No fluid is low. We ran 20 pounds of pressure and didn’t see any leaks. Idk what to tell you. When I drove it home. There was no coolant in the reservoir. I’m bringing it to a different dodge dealership in the morning. And I’m not sure if oil was in there. I can take a picture of the reservoir so you can see. This is my dads car. And he’s older so I’m just trying to help him figure this out. And thanks for your help

 

[Jenapher928]

 

[Himmelkat]

It sounds like a blown head gasket or the thin token gasket between coolant passage and the intake runner for which Dodge is famous is leaking coolant into the intake of one of the cylinders. A quick bore scope down the cylinders through a spark plug hole would show which cylinder had the most abnormally clean piston.

 

[Blickie]

I’m not sure. The dealership was a joke. They said. We did all the test. No fluid is low. We ran 20 pounds of pressure and didn’t see any leaks. Idk what to tell you. When I drove it home. There was no coolant in the reservoir. I’m bringing it to a different dodge dealership in the morning. And I’m not sure if oil was in there. I can take a picture of the reservoir so you can see. This is my dads car. And he’s older so I’m just trying to help him figure this out. And thanks for your help

@Jenapher928

Updated Comments...

Disappearing coolant at operating temp is an issue, and you have not reported any visible leaks or coolant tracks anywhere. The amount of coolant loss is notable and repeatable. Combustion getting into the coolant would raise the temp noticeably. Might be a head gasket. You might also pull all the plugs & see if any are really clean from steam, which occurs from a coolant leak into the cylinder(s).

The Recovery Tank needs to be filled to level and then the Pressure Tester needs to be installed, and then take the car for a drive to operating temp to see what the pressure does and what happens to the coolant level.

Some mention the thermostat. Thermostats are designed to fail OPEN, so it would take forever for the engine coolant to reach operating temp. While not impossible to fail closed, when it did over heat, you would not necessarily lose coolant because the system is totally tight and leakproof. The engine temp just overheats with no loss of coolant. Your reports say this is not happening.

I also don't like the dark colors in your Coolant Recovery Tank, which is not common on a tight cooling system. I think you also noted some residue (other than coolant) on the bottom of the Recovery Tank Cap.

Because of the coolant loss, you do need to insure coolant is NOT getting into the crankcase. If not visible to the naked eye on the dipstick or in the drained oil, then consider sending a crankcase oil sample out for an Oil Analysis, which will tell you immediately. Better to know then guess!

 

[Jenapher928]

Disappearing coolant at operating temp is an issue. Combustion getting into the coolant would raise the temp noticeably. Might be a head gasket. You might also pull all the plugs & see if any are really clean from steam, which occurs from a coolant leak into the cylinder(s).

Thank you. I’m going to have a different dodge dealer check all of that tomorrow morning. I only know a little about cars. But I’ll have the dealership take a look into other problems. Also. I did purchase an extended warranty for the car. Let’s hope shit is covered. I just had oil changed and they never said anything about the oil looking milky or anything. I’ll check myself and see if I see any of the dip

 

[Himmelkat]

As I said, it sounds like it is most likely the coolant being ingested, not the engine compression blowing the coolant OUT. Are there any signs of coolant overflow? One of the guys on here got the engine replaced on warranty due to this, so you may be on the lookout for them trying to weasel out of it, as it has happened before, the engine being ruined by guzzling its own coolant.

 

[borden72]

There's been an issue with the seal on the reservoir cap leaking coolant as well. Coolant will go out the overflow tube. I'd give that a check too.

 

[Dennis H]

Stay calm. Was the thermostat replaced? Find a reliable shop who is not a dealer.

 

[Mopar23]

I had a similar experience on another car and it was a bad thermostat

 

[baabootoo]

Did I miss if the fans were working properly??????????

 

[Mattm400]

First of all, 221° is not overheating by any means. But if you are smelling coolant, then you have a slow leak or it's seeping out from somewhere enough to cause evaporation.