Coolant Loss

[jpneely]

Hey guys, trying to figure out what the problem is with my 2005 LC. just got it from my inlaws a few months ago and noticed that the coolant was low in the reservoir. not empty, but at the low mark. filled it up and noticed that the level dropped again. started looking and found coolant on the bottom bolts of the radiator and saw no other coolant anywhere. the radiator had 231,000 mi on her so I replaced it and it solved the leaking radiator problem. but im still losing coolant somewhere. im not seeing it on the ground, or on any hoses which worries me, but im also not seeing any white smoke out of the tailpipe or any issues idling. the oil looks pristine and the radiator cap is brand new so im not sure where it can be going. the coolant in the radiator is still a perfect clear red color and no contaminants to be found. where else should I be looking? I figure my next step is getting it compression tested. it has overheated once as far as I know. the heater T's failed going down the interstate. but that was maybe 50k miles ago?

Oh also shes not overheating at all. the highest ive seen is 195ish on the OBD2 reader.

Thanks for your time.

 

[94SRUNNER]

I would double check all coolant hoses and connections. I have had small slow leaks on aluminum coolant components where pitting occurred between aluminum and coolant hoses. Last fall I had an oring, on the back side of water pump where coolant hardline connects, fail and lost coolant.

 

[jpneely]

I would double check all coolant hoses and connections. I have had small slow leaks on aluminum coolant components where pitting occurred between aluminum and coolant hoses. Last fall I had an oring, on the back side of water pump where coolant hardline connects, fail and lost coolant.

I’ll check the hardlines a little more but it’s burning through about a reservoir worth of coolant every 2 or 3 tanks of gas. That’s a good bit right? That should leave drips around the engine and frame right?

 

[94SRUNNER]

I’ll check the hardlines a little more but it’s burning through about a reservoir worth of coolant every 2 or 3 tanks of gas. That’s a good bit right? That should leave drips around the engine and frame right?

Yes. That is a large loss. I would suspect you’d see some coolant, somewhere.

Have you pulled the belly pans so you can inspect closer?

You said the oil looks good? Maybe worth pressure testing the system, see if that will help pinpoint the leak.

 

[jpneely]

No, haven’t pulled any pans, I just did the radiator last Monday hoping it would solve all the problems.

 

[94SRUNNER]

Well the other thing is if you didn’t properly burp the coolant system and there was a lot of air trapped inside, that could account for the drop in your reservoir level.

Did you burp the coolant system with the front end elevated and the radiator cap off?

 

[jpneely]

Well the other thing is if you didn’t properly burp the coolant system and there was a lot of air trapped inside, that could account for the drop in your reservoir level.

Did you burp the coolant system with the front end elevated and the radiator cap off?

Nope. Didn’t do that either. Would that be a reservoir and a half worth though? The half I can almost account for with a hose clamp that didn’t seat right. So maybe a full reservoir.

 

[94SRUNNER]

If you did not spend any time bleeding the air out and just dumped coolant in until the radiator was full and then topped off your reservoir. Then it’s possible you had a lot of air in the system and that is why your reservoir keeps emptying, because it’s displacing the air that’s in the system.

It will be worth your while to follow the coolant system bleeding process that is well documented on this forum.

Once a proper system bleeding has occurred then you can properly monitor for coolant loss by other means.

 

[jpneely]

If you did not spend any time bleeding the air out and just dumped coolant in until the radiator was full and then topped off your reservoir. Then it’s possible you had a lot of air in the system and that is why your reservoir keeps emptying, because it’s displacing the air that’s in the system.

It will be worth your while to follow the coolant system bleeding process that is well documented on this forum.

Once a proper system bleeding has occurred then you can properly monitor for coolant loss by other means.

Fair enough. I’ll search for The procedure for burping it. It’s a relief that this could be the problem. Thanks for the heads up.

 

[94SRUNNER]

Fair enough. I’ll search for The procedure for burping it. It’s a relief that this could be the problem. Thanks for the heads up.

Not a guarantee but it’s definitely worth doing.

 

[JunkCrzr89]

Well the other thing is if you didn’t properly burp the coolant system and there was a lot of air trapped inside, that could account for the drop in your reservoir level.

This . You keep talking about the reservoir level but haven’t mentioned anything about the level in the radiator. How did you fill the system when you replaced the radiator?

 

[jpneely]

I filled i

This . You keep talking about the reservoir level but haven’t mentioned anything about the level in the radiator. How did you fill the system when you replaced the radiator

I filled it through the radiator until it was full then filled the reservoir to the full line after that. Ran 10 min, topped everything back off.

 

[94SRUNNER]

I filled i


I filled it through the radiator until it was full then filled the reservoir to the full line after that. Ran 10 min, topped everything back off.

I presume you sealed everything back up and either let it idle of drove around for 10 minutes?

 

[jpneely]

I presume you sealed everything back up and either let it idle of drove around for 10 minutes?

Yep. Buttoned everything up, ran at idle for 10 min checking for leaks. Then after no leaks or drop in level, took it for a drive, watching the temp and stopping every few miles to look things over for leaks.

 

[abuck99]

I filled i


I filled it through the radiator until it was full then filled the reservoir to the full line after that. Ran 10 min, topped everything back off.

You may not have purged all the air from the system- you should have used at least 2gal of coolant for a radiator swap maybe a bit more.

Purging cooling system helps when done front end higher than rear end, while engine running radiator cap removed (purge funnel attached) heater on HOT, squeezing hoses to get bubbles to clear. After it reaches operating temp- you can spend 20min purging air. When completed the coolant should be at the top of the neck- and over flow to the high line.

 

[jpneely]

You may not have purged all the air from the system- you should have used at least 2gal of coolant for a radiator swap maybe a bit more.

Purging cooling system helps when done front end higher than rear end, while engine running radiator cap removed (purge funnel attached) heater on HOT, squeezing hoses to get bubbles to clear. After it reaches operating temp- you can spend 20min purging air. When completed the coolant should be at the top of the neck- and over flow to the high line.

Alright. I’m almost at 2gal back into the system then. I’ll keep purging air. The front end is on jack stands now as high as I could get the front end. I love on the coast so not really any good hills to park on to get it high. Thanks for y’all’s help

 

[jpneely]

I got a funnel to help burp the system and put her back on the jack stands and ran her with the heat rolling full tilt for about an hour and didn't see anything besides when id squeeze the top rad hose and move coolant in the radiator, tiny tiny bubbles that are almost nonexistent. never any big burps, or bubbles. so far ive got 2 gal even in and shes back down to the low mark in the overflow. she still runs like a champ, no smoke, oils clean as can be, and stays at 195 ish even when its 90+ with the AC going. unless yall see some red flags im going to keep adding coolant till she slows down and have the shop compression test her next time I have her in there.

 

[JunkCrzr89]

so far ive got 2 gal even in and shes back down to the low mark in the overflow

The entire cooling system holds 4.2 gallons.

 

[jpneely]

Update: Coolant levels seem stable now. I saw a little pink crystallization on the the upper radiator hose where it joins with the block so I cleaned up that connection and retightened the hose clamps. I don't see how that spot could have lost that much coolant without me seeing any signs until now, but it could very well have been a combo of still bleeding air out and a small leak at the hose. Thank yall for the information and back-up. ultimately she did take a little over 2 gallons after the radiator replacement.