Coolant Update

New to me '02 250k miles, previous post mentioned slight coolant loss and feared it was the head gasket. Then narrowed it down to potential Heater Core failure. Took it to the shop, they told me it should be fine and didn't notice any signs.

However, each time I drive and park overnight, the reservoir looses about half an inch of coolant! It doesn't expand either, when checking it while hot. It seems to stay in the same place while running and after top off, but after I've driven it and parked overnight it has that slight loss.

I'm perplexed! Any ideas what this could be? The only sign of loss I can discover is the truck smells like sweet coolant after running.

 

I would personally get a second opinion for the diagnosis.

 

Honestly, if there’s an external leak, you will notice coolant dripping from where ever it is leaking from. You should not be able to smell anything sweet unless it is burning.

A cracked heater core leak will be front to the firewall/floor board. Even if there’s a clamp failure from the hose to the core, the amount of pressure the cooling system is under will force coolant flow.

Try idling later at night or early morning for 20-30 minutes with the heater on at full blast and check for damp carpet or drip.

 

If you're smelling coolant there's a leak somewhere

Did the shop charge for their inspection? I'll bet they just don't want to do the heater core job..

 

If coolant system working properly, it’s under pressure. This pressure will push coolant somewhere even when engine at rest……like 02hilux says….a leak somewhere

“The truck smells like sweet coolant”

can u elaborate on this statement?
Inside cab
Engine bay
Exhaust

 

My coolant reservoir was suddenly dry. Turns out it was the radiator needing replacement. No, they don’t necessarily show fluid on the ground. It weeps out slowly thru fine cracks. Your fluid loss is more regular and might have other causes.

 

yeah on the crimp top radiators.....if it leaks at top, the fan blows it back onto the engine

this is the only good quality I can think of about the pink coolant........makes it easier to find leaks

.....built in leak dye

 

Same thing happened to me, crimps leaked and small cracks in the radiator plastic top.
Always needed to refill reservoir. New rad fixed all that

 

Mine ended up being the radiator. I couldnt see it leaking after i turned it off. Then it started leaking like crazy after a few days.

 

You may be able to borrow a cooling system pressure tester from an auto parts store for free as a loaner tool to see if it holds pressure.

Look for pink residue around the top and bottom edges of the radiator and around all of the hoses. It is also possible that the water pump is leaking from the weep hole, but look for the most simple places first.

How much coolant have you added to the system already to top it off?

 

Check the weep hole on the water pump

 

@Roadie_

We like to hear results, not crickets

Did you get it figured out?

 

Lots going on the past few weeks, with lots of travel in the truck. Two 9hr trips, with a few additional 3hr trips in between without any major coolant loss! I might have lost about half an inch (measuring while cold) since this post and about 3k miles of driving.

I believe the truck sat, or was very rarely driven since 2022. Dealership oil change sticker could attest to that. It displayed next service was set for Christmas day, 2022 or at the exact milage it was purchased at.

Previous owner sold it to a "mechanic" who did the timing belt and a few other things. They most likely forgot to top off the reservoir, just as they forgot to plug back in one of the AC pressure plugs. What a nightmare that was to figure out, when it ended up just being a disconnected plug. Ice Cold AC now though!

Anyways, no coolant smell after drives as it had when I purchased. Most likely was overspill from filling the radiator, and smell was coming from it burning on hot components. No leaks after any length of drives. Will continue to monitor the reservoir over time and continue to do some much needed maintenance.