V6- coolant not siphoning back from coolant overflow (not overheating)

[djtc]

Hi guys need some tips here. I am about 11 hours away from home and having some coolant problems.

So, the first stop on my trip i noticed some coolant dripping from the coolant overflow tank. Now the truck is behaving like it should with no overheating. First thing I did was unbolt the tank and dump it back in to the rad . 2 hours later I was able to get some coolant and a new rad cap. Filled the rad to the top and replaced the cap... No difference. Coolant dumping into the overflow tank and not going back to the rad with no overheating.

 

[progress4m]

Hi guys need some tips here. I am about 11 hours away from home and having some coolant problems.

So, the first stop on my trip i noticed some coolant dripping from the coolant overflow tank. Now the truck is behaving like it should with no overheating. First thing I did was unbolt the tank and dump it back in to the rad . 2 hours later I was able to get some coolant and a new rad cap. Filled the rad to the top and replaced the cap... No difference. Coolant dumping into the overflow tank and not going back to the rad with no overheating.

Could be bad thermostat… but since you are not seeing any overheating and since you have a V6… I hate to say it but it could be HG… exhaust gasses creating higher pressure than rad cap can hold and pushing fluid into the expansion tank… sorry for the bad news.... and I do hope that my second suggestion is wrong...

 

[djtc]

I really hope so too at only 120 000miles! Hopefully I can make the trip back home and perform some tests.

 

[wnelax04sr5]

i think the problem lies local to the radiator. if it starts and runs fine and you don't see any coolant leaks along the heads then you can probably rule out any HG failures

 

[djtc]

No other symptoms. Ill replace the cheaper stuff first.

 

[TechWrench]

Check to see if the return line from overflow tank to radiator is pinched/blocked. Also you may have air in the system. Did you bleed the system after filling radiator and overflow tank?

 

[JKC2638]

It might be as simple as a small leak in the cooling system. When your cooling system cools it will pull coolant back into the radiator through a suctioning effect. If you have any leak even small this will pull air into the cooling system and then when it gets hot and expands pushes more coolant into the overflow. Look at all your hose clamps for any sign of coolant. Might just have to re position a clamp.
Hope for an easy fix.

 

[SkylineGTRracer]

Have you check your water pump and gasket? My gasket was bad during one of my track days and raced with the heater on to not over heat. I replaced both the gasket and the water pump as the bearing had a little play and both were original. BTW Toyota has a revised/updated water pump for the 1gr.

 

[BOSMECH]

First thing I would do is have the system pressure tested then go from there.
I think autozone will do it for free or your local auto parts store.

 

[djtc]

i have not driven the truck since I got to my desination 11 hours away from home;but today i started the truck and let it run with the rad cap off. There was a lot of air in the system! Even after letting it run for 25min there was still a bubble every once in a while but it was much better. Ill have to see how it does on the way back home thursday.

 

[BOSMECH]

Let us know so it will help others here.

 

[RPS13]

Honestly, that sounds like either a pretty good leak, or a blown HG.

 

[chitown40]

I've experienced the same symptoms after doing a coolant change. For some reason these trucks just make it a little more difficult to bleed all the air pockets out of the system. You really need to get the nose of the truck pretty high in the air to help those last few bubbles make their way out.

 

[djtc]

I've experienced the same symptoms after doing a coolant change. For some reason these trucks just make it a little more difficult to bleed all the air pockets out of the system. You really need to get the nose of the truck pretty high in the air to help those last few bubbles make their way out.

The problem is that I did not work on the cooling system lately.So air was introduced into the system somehow. Fingers crossed on not being the hg.

 

[djtc]

Passed the Block test. Next up ill fill the cylinders with some pressurised air to see if the coolant will bubble.

 

[BOSMECH]

Let us know what happens again.

 

[djtc]

I just thought to bring this up but...do any of you hear a sound of rushing fluid/waterfall like behind the dash when the starting up your runners?I notice it in the mornings when the engine is cold...I wonder if its my heater core that is causing these issues.

 

[Mike07SE]

Haven't had the issue on the 4Runner, but did on one of my past Grand Cherokee's. Sounds like it could be a heater core as you've mentioned. Get it up to temp and turn the defroster on HI heat. See if you can pay attention under the truck and see if you can catch fluid coming out of the HVAC box drain hole. This may give you the answer you looking for.

*** Also, a cracked heater core blowing on defrost will also steam up and layer a film on the windshield...

 

[djtc]

Quick update: changing all the minor things did not help. I am in the process of doing the headgasket.

 

[fdbyrne]

I'm really sorry to hear that man. That really sucks.