Found a coolant leak

[Rebel_driver]

I have been topping up coolant occasionally but not very much. Noticed a leak today while looking under the hood. Anyone know what this is that is leaking?

 

[djevox]

Looks like the thermostat housing is leaking judging from the red crust around the edges of the housing.

Edit: can you take a pic of the other side between the right side of the upper radiator hose and the air charge intake hose?

 

[Rebel_driver]

Here’s a pic of the right side. It doesn’t look as bad as the left side.

Side note: I did have the water pump replaced on this truck about a year ago because it was squeaking. Tech possibly didn’t reassemble properly or reused an old gasket (if it was removed)?

 

[djevox]

Here’s a pic of the right side. It doesn’t look as bad as the left side.

Side note: I did have the water pump replaced on this truck about a year ago because it was squeaking. Tech possibly didn’t reassemble properly or reused an old gasket (if it was removed)?

That confirms it to me that it is the thermostat gasket leaking. It’s possible that the housing or the water pump side could be slightly warped, the tech reused something, or something just failed. It’s hard to say without being in front of the truck.

 

[Rebel_driver]

That confirms it to me that it is the thermostat gasket leaking. It’s possible that the housing or the water pump side could be slightly warped, the tech reused something, or something just failed. It’s hard to say without being in front of the truck.

Awesome. Thanks for the help. If I open that up to replace the gasket, coolant will spill out? Also, system will have to be bled once put back together?

 

[djevox]

Awesome. Thanks for the help. If I open that up to replace the gasket, coolant will spill out? Also, system will have to be bled once put back together?

Yes, and maybe. You can try to minimize it by using hose clamp pliers on the upper, lower, and bypass hoses, but you’ll still have a little but that comes out no matter what you do. It’s not a big deal though. If you clamp everything, just make sure when you’re done, you top off coolant in the tank, the truck gets to operating temp, and you check that the upper and lower hose feel similar in temp when the truck is fully hot. Make sure you don’t overheat while waiting, so if you cross 220 degrees on the coolant temp gauge, you have an air pocket that can’t work it’s way out and you need to bleed the system. You might as well cut the engine off right then and deal with the issue instead of overheating the engine.

On a similar note, if you have alpha OBD, or some other OBD two scan device, that can read live data, it’s better to monitor coolant temperatures through OBD than through the cluster. I think I’ve covered everything.

Edit: something that was taught to me and I’ve taught to many other people is that if I open a thermostat housing and the thermostat is not already brand new, as in less than 1000 miles, I replace the thermostat. The thermostat might not be bad, but it gives peace of mind that now the thermostat and the gasket are replaced and you won’t be pulling it apart again for a while. Granted, that mindset is a shop owner mindset, but I apply it to my personal vehicles as well.

 

[Rebel_driver]

Yes, and maybe. You can try to minimize it by using hose clamp pliers on the upper, lower, and bypass hoses, but you’ll still have a little but that comes out no matter what you do. It’s not a big deal though. If you clamp everything, just make sure when you’re done, you top off coolant in the tank, the truck gets to operating temp, and you check that the upper and lower hose feel similar in temp when the truck is fully hot. Make sure you don’t overheat while waiting, so if you cross 220 degrees on the coolant temp gauge, you have an air pocket that can’t work it’s way out and you need to bleed the system. You might as well cut the engine off right then and deal with the issue instead of overheating the engine.

On a similar note, if you have alpha OBD, or some other OBD two scan device, that can read live data, it’s better to monitor coolant temperatures through OBD than through the cluster. I think I’ve covered everything.

Edit: something that was taught to me and I’ve taught to many other people is that if I open a thermostat housing and the thermostat is not already brand new, as in less than 1000 miles, I replace the thermostat. The thermostat might not be bad, but it gives peace of mind that now the thermostat and the gasket are replaced and you won’t be pulling it apart again for a while. Granted, that mindset is a shop owner mindset, but I apply it to my personal vehicles as well.

I 100% agree with your mindset, do it once do it right. Thanks for all the input. Very much appreciated.

 

[Darksteel165]

Yes, and maybe. You can try to minimize it by using hose clamp pliers on the upper, lower, and bypass hoses, but you’ll still have a little but that comes out no matter what you do. It’s not a big deal though. If you clamp everything, just make sure when you’re done, you top off coolant in the tank, the truck gets to operating temp, and you check that the upper and lower hose feel similar in temp when the truck is fully hot. Make sure you don’t overheat while waiting, so if you cross 220 degrees on the coolant temp gauge, you have an air pocket that can’t work it’s way out and you need to bleed the system. You might as well cut the engine off right then and deal with the issue instead of overheating the engine.

I'm looking to replace my 203 with a 180 thermostat (hemi not diesel).
Do you think this would be simple to throw in without anything else? CST 180* Thermostat for 5.7L and 6.1L Hemi

Do you have any hose clamp pliers you would recommend?
Also I assume once you remove the hose where the thermostat is you can just point it up and gravity will keep the remaining coolant inside and anything that drips will burn off in a few days?

 

[djevox]

I'm looking to replace my 203 with a 180 thermostat (hemi not diesel).
Do you think this would be simple to throw in without anything else? CST 180* Thermostat for 5.7L and 6.1L Hemi

Do you have any hose clamp pliers you would recommend?
Also I assume once you remove the hose where the thermostat is you can just point it up and gravity will keep the remaining coolant inside and anything that drips will burn off in a few days?

I can’t answer about the 180° thermostat because I don’t know how the 5.7 hemi likes the cooler temps. It’s quite possible you could increase knock count, cause detonation, etc. Personally, I would only consider that on a street vehicle for high temp loads like forced induction or heavy towing. (Large stress on engine)

The clamps are like these hose clamps (not HF specifically, just that type of plier). I apologize, I said hose clamp pliers earlier which is actually the wrong term for the needed tool. They will stop the coolant flow if you apply them to the proper coolant hoses for the component you’re working on.

For the coolant burning off, you don’t want that. At the shop if we have a large area on a vehicle that has coolant everywhere, the tech will drive into a cordoned off area and pour water all over the areas they worked in (water and coolant gets sent out to Safety-Kleen). For small areas, we use brakeclean and an airgun to dry it. The last thing you want is coolant stains everywhere so you cannot tell where a coolant leak is coming from.

 

[Darksteel165]

I can’t answer about the 180° thermostat because I don’t know how the 5.7 hemi likes the cooler temps. It’s quite possible you could increase knock count, cause detonation, etc. Personally, I would only consider that on a street vehicle for high temp loads like forced induction or heavy towing. (Large stress on engine)

The clamps are like these hose clamps (not HF specifically, just that type of plier). I apologize, I said hose clamp pliers earlier which is actually the wrong term for the needed tool. They will stop the coolant flow if you apply them to the proper coolant hoses for the component you’re working on.

For the coolant burning off, you don’t want that. At the shop if we have a large area on a vehicle that has coolant everywhere, the tech will drive into a cordoned off area and pour water all over the areas they worked in (water and coolant gets sent out to Safety-Kleen). For small areas, we use brakeclean and an airgun to dry it. The last thing you want is coolant stains everywhere so you cannot tell where a coolant leak is coming from.

My tuner guy asked me to get a 180 a while back so I think he would just make the adjustments when I change it anyways so i'm not worried about knock.

I knew you were talking about the line clamp but I didn't know the name because I looked up the hose clamp pliers and was thinking I just use a regular pair of players for those.

What do you think about a clamp like this? Just thinking might be stronger then the plastic ones. Not sure how strong the tubing is.

https://www.amazon.com/Rustproof-Strength-Universal-Stainless-Radiator/dp/B0BM8D6H9Q/

Or maybe this? https://www.amazon.com/GearWrench-145-Hose-Pinch-Pliers/dp/B000O3NACS/

I guess I can try and be extra careful to not get any coolant anywhere. Maybe use a throw away towel under it and then rinse it with a hose and dry it with my shop vac or leaf blower (never used to blow leafs) to dry it.

 

[djevox]

My tuner guy asked me to get a 180 a while back so I think he would just make the adjustments when I change it anyways so i'm not worried about knock.

I knew you were talking about the line clamp but I didn't know the name because I looked up the hose clamp pliers and was thinking I just use a regular pair of players for those.

What do you think about a clamp like this? Just thinking might be stronger then the plastic ones. Not sure how strong the tubing is.

https://www.amazon.com/Rustproof-Strength-Universal-Stainless-Radiator/dp/B0BM8D6H9Q/

Or maybe this? https://www.amazon.com/GearWrench-145-Hose-Pinch-Pliers/dp/B000O3NACS/

I guess I can try and be extra careful to not get any coolant anywhere. Maybe use a throw away towel under it and then rinse it with a hose and dry it with my shop vac or leaf blower (never used to blow leafs) to dry it.

Yeah, whichever clamp you like is fine. All any of them do is pinch the hose shut anyway, so I don’t see a problem with any kind that doesn’t damage the hose.

I can’t advocate for coolant potentially going on the ground, but old timers used to fill watering containers (like for a garden) with water and dump it over the area that had coolant. Then they’d drive it to let heat and air dry it.

 

[Darksteel165]

Yeah, whichever clamp you like is fine. All any of them do is pinch the hose shut anyway, so I don’t see a problem with any kind that doesn’t damage the hose.

I can’t advocate for coolant potentially going on the ground, but old timers used to fill watering containers (like for a garden) with water and dump it over the area that had coolant. Then they’d drive it to let heat and air dry it.

Yeah I understand that.
Would be going on my driveway if anything not leaking into the earth.

Guess i'm adding on another project for myself now.

 

[tom318]

No luck on finding my coolant leak after some pressure testing today. When cold, it held 20psi for 20-25min. Got it up to temp and it climbed to about 20psi and then slowly came back but that may be due to it simply cooling down. Where is it going!!! It’s consumed about a gallon over the last 7-10k miles. Egr cooler? Pictures are at operating temp after the engine was shut down 12minutes between pictures. Also no visible leaks anywhere and potassium was higher on oil report....so it seems to be getting into the oil as well? Not to sure.
It is under warranty still but I hit a deer and the bumper is smashed so I don’t want to take it in until that’s repaired. Nothing is damaged from that impact form what I can see.

 

[djevox]

No luck on finding my coolant leak after some pressure testing today. When cold, it held 20psi for 20-25min. Got it up to temp and it climbed to about 20psi and then slowly came back but that may be due to it simply cooling down. Where is it going!!! It’s consumed about a gallon over the last 7-10k miles. Egr cooler? Pictures are at operating temp after the engine was shut down 12minutes between pictures. Also no visible leaks anywhere and potassium was higher on oil report....so it seems to be getting into the oil as well? Not to sure.
It is under warranty still but I hit a deer and the bumper is smashed so I don’t want to take it in until that’s repaired. Nothing is damaged from that impact form what I can see.
View attachment 158817 View attachment 158818

Stop now and get it in for warranty. You can always not accept the repair if it’s not under warranty, then repair it yourself. You don’t want to end up needing a new engine if there’s an egr cooler leak. Did you scope the cylinders? If coolant was getting into your oil, it would look like a light brown milkshake. If you let it sit and get cold, then the oil and coolant will separate. If you crack the drain plug after it sits overnight and you get coolant out, then you know.

 

[tom318]

Stop now and get it in for warranty. You can always not accept the repair if it’s not under warranty, then repair it yourself. You don’t want to end up needing a new engine if there’s an egr cooler leak. Did you scope the cylinders? If coolant was getting into your oil, it would look like a light brown milkshake. If you let it sit and get cold, then the oil and coolant will separate. If you crack the drain plug after it sits overnight and you get coolant out, then you know.

I'm concerned if its not covered under warranty due to the visible damage to the bumper then it will never be and then they will reject any claims moving forward. Not only that but ill be forking up money for the diagnosis......not a fan of the situation ive put myself in by dragging my feet on this front end repair. Live and learn I guess.

I didn't notice anything visibly different when I changed the oil 1k miles ago. What leads me to think it was in the oil was the oil analysis report which had elevated potassium by 10ppm compared to my last oil change. Blackstone didn't say anything about that but the aluminum was also higher like it always is for others.
Maybe ill stop driving it for now and let it sit. Since the oil change, and really since the last 3k miles I haven't seen the coolant come down.

 

[HSKR R/T]

Yes, and maybe. You can try to minimize it by using hose clamp pliers on the upper, lower, and bypass hoses, but you’ll still have a little but that comes out no matter what you do. It’s not a big deal though. If you clamp everything, just make sure when you’re done, you top off coolant in the tank, the truck gets to operating temp, and you check that the upper and lower hose feel similar in temp when the truck is fully hot. Make sure you don’t overheat while waiting, so if you cross 220 degrees on the coolant temp gauge, you have an air pocket that can’t work it’s way out and you need to bleed the system. You might as well cut the engine off right then and deal with the issue instead of overheating the engine.

On a similar note, if you have alpha OBD, or some other OBD two scan device, that can read live data, it’s better to monitor coolant temperatures through OBD than through the cluster. I think I’ve covered everything.

Edit: something that was taught to me and I’ve taught to many other people is that if I open a thermostat housing and the thermostat is not already brand new, as in less than 1000 miles, I replace the thermostat. The thermostat might not be bad, but it gives peace of mind that now the thermostat and the gasket are replaced and you won’t be pulling it apart again for a while. Granted, that mindset is a shop owner mindset, but I apply it to my personal vehicles as well.

As long as you don't buy the cheapest thermostat available and it's bad out of the box

Also, the upper and lower radiator hoses should not be the same temp. The lower hose should be noticeably cooler than the upper hose. Otherwise the radiator isn't doing its job.

 

[djevox]

As long as you don't buy the cheapest thermostat available and it's bad out of the box

Also, the upper and lower radiator hoses should not be the same temp. The lower hose should be noticeably cooler than the upper hose. Otherwise the radiator isn't doing its job.

that’s not accurate, and note that I didn’t say same temp.

 

[djevox]

I'm concerned if its not covered under warranty due to the visible damage to the bumper then it will never be and then they will reject any claims moving forward. Not only that but ill be forking up money for the diagnosis......not a fan of the situation ive put myself in by dragging my feet on this front end repair. Live and learn I guess.

I didn't notice anything visibly different when I changed the oil 1k miles ago. What leads me to think it was in the oil was the oil analysis report which had elevated potassium by 10ppm compared to my last oil change. Blackstone didn't say anything about that but the aluminum was also higher like it always is for others.
Maybe ill stop driving it for now and let it sit. Since the oil change, and really since the last 3k miles I haven't seen the coolant come down.

I’d want to see if there’s coolant in one or more cylinders then.

 

[HSKR R/T]

that’s not accurate, and note that I didn’t say same temp.

What's not accurate?

And you said the upper and lower hoses should feel "similar" in temp. But the lower hose should be noticeably cooler. Not what I would consider similar

 

[tom318]

I’d want to see if there’s coolant in one or more cylinders then.

Wouldn't you expect to see a puff of white smoke at startup? Especially after it sat @20psi for almost an hour?

Also, just read over the warranty and it looks like the EGR was only covered for 24k miles so might be on my own anyway if that's the issue. The 5yr 100k doesn't state a word about exhaust or emissions related items.