Eating coolant?

[DirtySouth89]

3 weeks ago I popped my hood and happened to notice the coolant reservoir at below the bottom line. Maybe a shotglass left. I've never even looked at coolant so I have no context for how long it had been like that. I bought some Asian red coolant and filled it to an inch above the topmost line. Within a week it was down another 2 inches (feeding the rad?), and within 3 weeks, down below the minimum line again. None is visible leaking to the ground, any ideas?

Context: It's the V8, had the timing belt/water pump done just 1,700 miles ago.

 

[hankd]

there is a part near the top front of engine that has a gasket (possibly going to the thermostat maybe?) which starts leaking on a lot of v8's after they have the timing belt job done. happening to me too but i'm just going to leave it as-is and top it up once in a while. some folks don't address it and it seems to only leak til the reservoir says low and the level will stabilize there. there are some other threads with more info on this.

 

[pauldub]

Did you take off the radiator cap and see if the radiator was full? If the radiator isn't full, fill it first.

 

[DirtySouth89]

Did you take off the radiator cap and see if the radiator was full? If the radiator isn't full, fill it first.

I lifted off the radiator cap but it's a dark black skinny tube. Not sure what its supposed to look like up there at the cap. You can't actually see down it, it lets no light in.

 

[Whamola]

there is a part near the top front of engine that has a gasket (possibly going to the thermostat maybe?) which starts leaking on a lot of v8's after they have the timing belt job done. happening to me too but i'm just going to leave it as-is and top it up once in a while. some folks don't address it and it seems to only leak til the reservoir says low and the level will stabilize there. there are some other threads with more info on this.

Yup. Happened here. Took a while to even notice where it was leaking out. I just keep an eye and add as needed. I think mine tends to leak more when it's cold. It's annoying to refill, but honestly....a hell of a lot cheaper than pulling it all apart. I think I'm on jug 4 or 5 in 8 years.

 

[Bassturd]

I lifted off the radiator cap but it's a dark black skinny tube. Not sure what its supposed to look like up there at the cap. You can't actually see down it, it lets no light in.

He meant the actual radiator cap not the overflow reservoir cap. Check it when it’s cold always and if it’s low fill the radiator first then the overflow. Good luck.

 

[pauldub]

Fill up the radiator. It should be filled to the brim. Then fill the overflow tank to the cold line and drive for some days and see if the level in the overflow tank changes much.

 

[AuSeeker]

First is that you should be using "Pink" Asisn coolant for all 4th Gens T4Rs not red which is used in 3rd Gens.

You obviously have a leak/s somewhere, look for pink crystallization to find where the leak/s are, could be at the top front of the engine, any coolant hoses and or the corners of the radiator usually the bottom corners, sometimes it's hard to see if it's the radiator because of the shroud.

But until you find and fix any leaks do what has been suggested by others, fill cold radiator first and the the plastic reservoir.

 

[delucat2]

I always start with a new radiator cap and adding a package of AlumAseal. If it is a slow exterior leak, you will eventually be able to find the red crusty buildup.

 

[fefe_grn210]

there is a part near the top front of engine that has a gasket (possibly going to the thermostat maybe?) which starts leaking on a lot of v8's after they have the timing belt job done. happening to me too but i'm just going to leave it as-is and top it up once in a while. some folks don't address it and it seems to only leak til the reservoir says low and the level will stabilize there. there are some other threads with more info on this.

Is this a common area for the V6 to leak as well? Coolant on mine is also disappearing and I'm trying to track down the cause.

 

[Sunn4Runner]

Is this a common area for the V6 to leak as well? Coolant on mine is also disappearing and I'm trying to track down the cause.

I have a 2003 V6 and yes I was losing coolant, and noticed some crystalization on my radiator. I replaced with a a new Denso rad and its all good now, no coolant loss.

 

[Drcoffee]

The radiators in general are a weak point IMO on 4th gen 4runners. Same for the 3rd gen. The radiators have plastic side tanks in the 4th gen and the radiator is rigidly mounted to the radiator support by 4 bolts. There are rubber isolators but they dont do much to absorb continuous vibrations. So the side tanks weaken at the seal causing a leak undetected.

In 3rd gen 4runners, the plastic tanks are mounted top and bottom. The same rigid mounting system with four bolts. In these, the vibration causes the internal transmission cooler to vibrate and break over time, leading to a pink milkshake, where coolant and atf mix destroying the transmission.

It would be nice if toyota could design a more forgiving radiator mounting system. I havent looked at the 5th gen trucks yet. They may have figured it out by now, but doubt it.

 

[BackOff]

Blacklight makes the antifreeze glow bright pink...phosphates.

 

[FordF150]

yOU HAVE A LEAK SOMEWHERE. Maybe check the WP you installed. Did you use the steel Toyota gasket?

Keep it full. One overheat and ruin a 4runner performance.

Check radiator. When you take cap off, is it low? Get a new cap.

Find the leak.:clap2:

Use the pink coolant long life.

I have 2005 with 150,000 miles. I check my coolant canister twice a week. If that overflow canister is ever low by much I find out why.

A bad overheat can ruin any engine beyond repair.

Good luck.