(Edit: Found leaking radiator that needs replacing.)

Not sure it's a problem but thought I'd see if others have noticed the same issue.

I've had the truck since new. Now at 206000 Km (~128000 mi) and starting to use coolant.
I drain and refill with 2 gallon jugs of OEM spec'd coolant every 2 years. Did this last October and slightly top up the reservoir tank in the process until I get a stable tank level.
I noticed about 3 months ago that for the first time the tank was almost empty. Topped it up and noted the mileage. Now 6000 Km later it's almost empty again. No obvious signs of a leak (rad, hoses, drain.)

Anyone else use coolant like this on a higher mileage vehicle?

Yep, but not on my 4runner...on my XJ cherokee (202,000+ miles). 'Drinks' coolant due to the infamous bad 0331 head casting...hairline crack in the head. Doesn't have white smoke, no 'milkshake' in the oil...except just under the oil cap (crack is just below the oil cap).

So, in your case, I would get some dye put into the coolant and have it pressure tested. But it could be anything...head gasket, cracked head, pin hole leak in the radiator...

How does it run...does it run hot...warmer than normal?

One thing you have to do as part of regular maintenance on the cooling system is replace the radiator cap...the spring and seals in them do wear out...

good luck.

Thanks for the info.

Was meaning to update this thread once I do some work on the rad. Runs fine. No increase in temp. Checked the rad cap and it's good.

Took a closer look on the weekend. There is a very slow leak in the rad in the joint between the core and the drivers side tank end. There is a metal band with "tangs" or "tabs" on it that act as a crimping to hold the seal between the core and the tank. Some of these tangs are not crimped over where the upper and lower tranny cooler hose fittings are. The leak is right at the upper uncrimped area. I'm planning to take the fan shroud off to get access to the side area of the rad in order to try and crimp the area closed.

Luckily it's not a bigger gasket or engine issue like I feared. Sorry, no pics yet but will do so as I work on this.

Glad to hear it doesn't seem to be a serious problem...but that seems like a defect that should not have left the factory...surprised it didn't give you problems in the very beginning...

good luck...

jwyshrek (or anyone else with a 4th Gen),

Not sure if this missed crimping is abnormal. Can you look at your rad to see if there are some uncrimped tabs in this location? Looks like they aren't crimped because of potentail interference with the hose fittings.

Can anyone get me the TIS repair manual pdf document for a radiator component repair? I thought I saw it before but can't find it. I don't want to rebuild the rad (not worth it) but I would like to know how it's supposed to be put together, especially the sealing and crimping.

Hey.

Yep, even though I have a V8...around the transmission lines and around the mounting points...those tabs are not crimped down onto the side tanks of the radiator. I guess for clearance. So, it is normal...

Maybe time for a new radiator...

Found time to take a closer look. Pulled the top trim cover off (pop out 11 clips) and it was immediately evident that:

Here's a (not so clear) before pic where I thought there was a small leak at the crimped joint near the top of the tank because of some pink coolant residue.

Attached Images

 

(Edit: Turns out it's not the seal or crimping.)
Here's the bigger issue at the top corner of the core.
New OEM rad from the stealer is C$927 + tax = 1047!
I've got an aftermarket on order for C$297 (includes tax.)

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Sheesh!

Gotta love it when they use cheap parts on a 25k-30k+ vehicle. It would have been nice if they had spent a few extra dollars and got an all metal radiator.

Well, now the mystery has been solved...I have a sudden craving for pink lemonade...