Coolant loss

[S.Dodge]

So never had this happen before. Driving on the highway and engine temp alarm came on. Pulled over and saw coolant leaking out the front of the engine. Let it cool down and got to a truck stop and overheated again. It's-10 degrees and a snow storm. The radius was empty and I filled it with coolant and it drained out again soon after.stopped again and used water because I was needing yo get home and it's still hot.

All of a sudden no more leaking and it holding the water. I'm about to drain it All again and flush to get coolant back in it. Could it be the t-stat just didn't open and it overflowed? Happen before in my diesel but it was a bad water pump. Not the issue right now because it stopped leaking. And ideas?

 

[Ken226]

Not the issue right now because it stopped leaking. And ideas?

What kind of driving was occuring when it overheated. Lot's of low speed, stoplight to stoplight and/or idling right before? Or all highway speeds?

You need to figure out where it was leaking from.

Until you know that, it could be anything and anywhere. The ceramic seal in the water pump has moving parts that will leak when it wants, under some conditions. Maybe it's only leaking when under pressure AND when the engine is running, or some other unknown condition that isn't always present.



Have the system pressure tested. That's how you find a leak that is only happening when the system is hot and under pressure.

If it holds pressure at design limits, then you can look at the fans and/or thermostat.

 

[S.Dodge]

I was on the highway for about an hour when It started to overheated. Very hard to see anything right now as it all covered in snow and ice

 

[Ken226]

I was on the highway for about an hour when It started to overheated. Very hard to see anything right now as it all covered in snow and ice

The thermostat is easy to test and rule out.

All you need is a pot of water on the kitchen stove and a thermometer.

 

[Jeepwalker]

Get a flashlight and an inspection mirror, or look up from below ....look underneath your truck's water pump. There's a weep hole under there. If it's wet at ALL and nothing is wet above the water pump ...then you most likely need to replace your water pump right away. And by right away, that means it's advisable to not drive your tk. When a water pump leaks, the coolant generally runs down the lower radiator hose and drips off the hose and easy to think it's a radiator issue ...or hose. The coolant washes the grease from the w/p bearings which make them 'Whirrrr' (noise). So the bearings will soon fail, when they start to leak. Yours may not be leaking but that's the first thing I would check.

Grab the fan (engine off ..lol) and rock the fan. See if there's any bearing 'play' there. like wearing water pump bearings. Start with the water pump and rule that out so you know it's at least safe to continue to drive the truck. Inspecting it takes 5-7 min.

If the water pump looks good, then check the radiator, cap, coolant level and other things. Do you see bubbles with the rad cap off...running the engine at 1200-1500 rpm? That could indicate a weak head gasket (causing over-pressurization). Just some things to put your eyes on.... Good luck

 

[S.Dodge]

So I got some new coolant and filled the rad after draining the water, didn't really get alot out. Filled it while idling and it bubbled and then the stat opened and hoses got hot and heat works. Topped up as required and see no leaks. Drove it around while hot and the no leaks and it's not overheating. Can't get it to overheat again. Not sure what's going on.

 

[Burla]

If you were driving an hour it wasnt going to be the t stat unless it was a total fail = not likely. There is no way for that valve to close under pressure when hot. Of the two usual culprits fans or water pump, sounds like water pump to me. It could however just be a leak as well, get some dye?

 

[S.Dodge]

If you were driving an hour it wasnt going to be the t stat unless it was a total fail = not likely. There is no way for that valve to close under pressure when hot. Of the two usual culprits fans or water pump, sounds like water pump to me. It could however just be a leak as well, get some dye?

I got it up to temp again and checked the play in the fan, zero play, tried to check the water pump for leaks but hard withbthe wet environment and all the undercoating. Drove it again, stat is operating correctly amd zero leaks, drove to a dry spot, let it idle and also at an elevated rpm. No leaking. I'm confused because a broken part would leak steady. Drained the rad a few time and checked the hoses, coolant is flowing.

 

[Ken226]

It's-10 degrees and a snow storm.

what was your coolant/water mix ratio before this happened?

It may not be likely, but it's possible with a temp of -10, for a coolant mixture with too much water to freeze in the radiator as air flows through, and block the flow of coolant, resulting in an overheat at the engine.

While it isn't likely, if this truck got low on coolant in its past and was topped off with water a time or three, it could have ended up with a coolant ratio that would freeze at -10.

Kinda just spitballing random, wild-assed ideas.

 

[Burla]

I got it up to temp again and checked the play in the fan, zero play, tried to check the water pump for leaks but hard withbthe wet environment and all the undercoating. Drove it again, stat is operating correctly amd zero leaks, drove to a dry spot, let it idle and also at an elevated rpm. No leaking. I'm confused because a broken part would leak steady. Drained the rad a few time and checked the hoses, coolant is flowing.

everytime I got in the car I would set evic to coolant temp../.

 

[wrench78]

Just went through something similar. Turned out my water pump had gone bad. I am now on my 3rd water pump since December 2024. It's been 1 week since the last install. Crossing my fingers that 3rd time is the charm. Oh and yes, it was the Ram Dealership that did the work.

 

[wrench78]

I got it up to temp again and checked the play in the fan, zero play, tried to check the water pump for leaks but hard withbthe wet environment and all the undercoating. Drove it again, stat is operating correctly amd zero leaks, drove to a dry spot, let it idle and also at an elevated rpm. No leaking. I'm confused because a broken part would leak steady. Drained the rad a few time and checked the hoses, coolant is flowing.

When my water pump went out, it didn't leak all the time. mostly only when up to temp and pressure. The dealership ended up doing a pressure test on it to find the leak.

 

[S.Dodge]

what was your coolant/water mix ratio before this happened?

It may not be likely, but it's possible with a temp of -10, for a coolant mixture with too much water to freeze in the radiator as air flows through, and block the flow of coolant, resulting in an overheat at the engine.

While it isn't likely, if this truck got low on coolant in its past and was topped off with water a time or three, it could have ended up with a coolant ratio that would freeze at -10.

Kinda just spitballing random, wild-assed ideas.

It was the factory coolant, never been topped up with water. A couple months ago it was -30C and no issues. I've owned it since new. It's filled back up now with the factory equivalent diluted to 50/50. It's really strange that it's not leaking or doing anything out of the ordinary now even after multiple heat cycles. When I pulled over on the side of the highway it was leaking out, almost pouring out when I was topping it up, all of a sudden stopped.

 

[Burla]

Coolant expands wit heat, dimes to donuts the underlying condition is still there, the hotter it gets can push through seals which are now compromised even if they aren't showing. You will know next time you travel for an hour. Might want to carry an over heat first aide kit, water wetter, coolant, some dist water, some silicone tape, some stop leak tablets.

 

[S.Dodge]

Coolant expands wit heat, dimes to donuts the underlying condition is still there, the hotter it gets can push through seals which are now compromised even if they aren't showing. You will know next time you travel for an hour. Might want to carry an over heat first aide kit, water wetter, coolant, some dist water, some silicone tape, some stop leak tablets.

Yeah I know the issue is still there. I was hoping it would be obvious. Truck is in a warm garage now so I'll check in the morning. I have lots of coolant now in the toolbox as well. I did notice that the leaking/pouring was from the passenger side and seemed like the front by the rad and not the front of the engine.

The last ride I went on was for about 20 mins and the temp on the evic never went above 96 degrees C even under heavy throttle up hill.

 

[Wild one]

Yeah I know the issue is still there. I was hoping it would be obvious. Truck is in a warm garage now so I'll check in the morning. I have lots of coolant now in the toolbox as well. I did notice that the leaking/pouring was from the passenger side and seemed like the front by the rad and not the front of the engine.

The last ride I went on was for about 20 mins and the temp on the evic never went above 96 degrees C even under heavy throttle up hill.

It's not that uncommon for the rads plastic side tanks to develop a leak that only shows up when the cooling system is at full pressure.I'm guessing you're in Canada,check your local Crappy Tire for their loan a tool program,they might have a pressure testor you can borrow

 

[S.Dodge]

It's not that uncommon for the rads plastic side tanks to develop a leak that only shows up when the cooling system is at full pressure.I'm guessing you're in Canada,check your local Crappy Tire for their loan a tool program,they might have a pressure testor you can borrow

Yes I'm in Canada, after it's dried off tomorrow I will run it and check for any sign of a leak. I will try and do a pressure test as well.

 

[S.Dodge]

So a little update, I took the truck to a shop and they did a pressure test and said everything was all good and it's been weeks with no issue. Last night I was driving home and the engine over temp Alarm sounded so I went to pull over and it went away, the temps dropped and I drove home with no more issue but the temp was a little higher than normal. Cooled it down then checked the coolant and it was low. So it's got to be a very slow leak from somewhere because I've been using it daily with no issue and towing often as well. The pressure test shouod have found the issue.

 

[Ken226]

While driving at highway speeds again?

Intermittent overheating at highway speeds with plenty of airflow through the radiator would cause me to suspect a partial blockage.

How many miles are on the truck and how long since you've done a coolant flush? This is a commonly neglected system that can cause serious and expensive problems.

Maybe it's time for a flush with some CLR or RMI25, a new thermostat and a coolant replacement? If you are over 100,000 miles, a water pump replacement at the same time wouldn't hurt. I'm 2 for 2 on having a water pump **** the bed within weeks of a coolant flush.

If you have a shop do a flush, make sure to explain your concerns and have them watch for debris when they do the flush.

 

[S.Dodge]

I have about 120,000kms on it. I was travelling on back roads with varying speeds, about 80km/h at the time. I have new coolant in it from the last time but not a full blown flush.