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

[NOAAguy]

I came to this thread with a similar issue, or so I thought..

Bought a used 2005 (1GR-FE) SR5 with 174k miles a couple months ago.

Recently, after about 3 hours of highway driving, while stopped at a stoplight, I notice the temp gauge rising quickly, all the way to redline then stopping. Turned off A/C, ran heat, seemed to stop the rise. As soon as we picked up speed (~35mph+) and returned to highway, the temp needle went back to normal. Problem was persistent whenever at a stoplight. Upon further examination, I notice the overflow tank is empty. I fill it up, but none of the fluid was being drawn into the rad. After the engine cools, I open the rad cap and fill fluid straight in, takes an entire jug of coolant! Rad was completely empty. Unfortunately this problem is persisting with the loss of coolant and I cannot find out why.

Originally, I dreaded the HG, so I got a block tester and ruled out a blown HG.
Then, I borrowed a cooling system pressure tester to see if I could find the leak. I pumped about 16psi in, and the pressure slowly receded to about 15psi and held there for 20 or so minutes. Replaced the radiator cap as well.

Here I am, still losing coolant and not at all sure where it is coming from. Any similar experiences? Thanks.

 

[duffdog]

I came to this thread with a similar issue, or so I thought..

Bought a used 2005 (1GR-FE) SR5 with 174k miles a couple months ago.

Recently, after about 3 hours of highway driving, while stopped at a stoplight, I notice the temp gauge rising quickly, all the way to redline then stopping. Turned off A/C, ran heat, seemed to stop the rise. As soon as we picked up speed (~35mph+) and returned to highway, the temp needle went back to normal. Problem was persistent whenever at a stoplight. Upon further examination, I notice the overflow tank is empty. I fill it up, but none of the fluid was being drawn into the rad. After the engine cools, I open the rad cap and fill fluid straight in, takes an entire jug of coolant! Rad was completely empty. Unfortunately this problem is persisting with the loss of coolant and I cannot find out why.

Originally, I dreaded the HG, so I got a block tester and ruled out a blown HG.
Then, I borrowed a cooling system pressure tester to see if I could find the leak. I pumped about 16psi in, and the pressure slowly receded to about 15psi and held there for 20 or so minutes. Replaced the radiator cap as well.

Here I am, still losing coolant and not at all sure where it is coming from. Any similar experiences? Thanks.

Sounds like the heads are warped and the coolant is being burned and blown out of the exhaust. Not only is the head gasket bad, but the heads will have to be replaced or resurfaced. "block testing" cannot possibly determine if a cylinder is creating a vacuum and sucking the coolant from the jacket, only if the coolant is being pressurized from the piston and going out of the overflow. I say pull the heads and take them to a shop to determine if they are either leaking or warped.

 

[metramm]

I'm having the same issue as the OP. Losing coolant in the radiator and the overflow tank is full.

I've been checking it daily and using a turkey baster to move coolant from the overflow tank to the radiator until it is full.

No overheating, everything else running fine. No waterfall sound, so indication of a head gasket issue.

Did a pressure system test and it held just under 15 psi for 10 minutes without the needle moving. I was hoping for it to show a leak somewhere but nothing.

I checked all over.. all the hoses, radiator, water pump (from what I can see with the skidplate on).

Purchased a new Toyota OEM radiator cap first in hopes it was an easy fix but that didn't help.

I have an appointment at Romeoville Toyota tomorrow at 9:30am CT to have it checked out. I'm betting it is either a bad water pump or radiator. Seriously don't think a head gasket.

I keep you posted on what I hear. I need to have it fixed as I'm driving 1500 miles next Thursday and would prefer not to break down in the middle of nowhere Tennessee.

 

[Drcoffee]

If your are producing enough pressure to eject coolant and overflow the res, its most likely a HG. Once the engine is at ambient, pull #4 #6 spark plugs and check for coolant in the cylinders.

 

[metramm]

Just a quick update on this.

I dropped it at the dealer and the tech wasn’t able to find any visable leaks.

They kept it overnight as the tech wanted to check it this morning.

Waiting on a call from the dealer on an update.

I did forget to mention that I have been hearing a faint rattle/bearing noise coming from the water pump/power steering pump area.

I used a stethoscope to attempt to locate the sound and I could very clearly hear a bearing noise when I placed the probe on the power steering pump, but I wasn’t able to determine if the bearing noise was coming from the power steering pump or was actually coming from say the the water pump.

Also I did more research last night and discovered that the water pump bearing could cause a leak and might be a contributing factor on my coolant loss.

I’m leaning towards just having the dealer change the water pump as preventive maintenance as I’m at 231,000 and it is from 2006.

Not planning on having the thermostat changed unless it is cheap because I have plenty of heat and I can change that myself.

Please let me know if anyone has experienced these issues and performed a water pump change to correct it.

I’ll let you know what I decide and if it corrects the issue.

 

[Drcoffee]

The only situation I know of that blows coolant into the res tank would be a head gasket. Normal flux from hot to cold would only raise the level few inches. Even if the water pump had a bad bearing, the impeller is still spinning and circulating the coolant

 

[metramm]

Picked up my truck from the dealer an hour ago.

The tech didn't find any issues with the cooling system. Below is from the work order word for word:

"MISC: Customer states
The radiator overflow tank keeps filling up with coolant from the radiator. Customer stated he couldn't find any visible leaks and has also had it inspectd at another Toyota dealer.
Please advise. Customer recently replaced radiator cap.
Caused by:
No problem found, could not duplicate condition.
Tech:
Checked coolant level, ok.
checked for leaks, none found
tested for blown head gasket, no co2 gas detected in cooling system.
Head gasket ok at this time.
Ran multiple cool and heat cycles to observe and worked normal."

They didn't charge me for the inspection since nothing was found.

I was advised to monitor the coolant level.

I did ask the service advisor if the tech heard any rattling bearing noise while working on the truck and he stated no, but I can hear it in the garage while idling.

I guess from here I'm going to just check the coolant weekly and before every long trip and fill the radiator as needed, and listen for that bearing/rattling noise to see if it gets any louder.

I have 100 mile towing on my AAA so if I break down I can always have it towed and fixed at that point in time.

Thanks for all the assistance with this and if anything changes/breaks I will update this thread.

 

[the_josh]

Picked up my truck from the dealer an hour ago.

The tech didn't find any issues with the cooling system. Below is from the work order word for word:

"MISC: Customer states
The radiator overflow tank keeps filling up with coolant from the radiator. Customer stated he couldn't find any visible leaks and has also had it inspectd at another Toyota dealer.
Please advise. Customer recently replaced radiator cap.
Caused by:
No problem found, could not duplicate condition.
Tech:
Checked coolant level, ok.
checked for leaks, none found
tested for blown head gasket, no co2 gas detected in cooling system.
Head gasket ok at this time.
Ran multiple cool and heat cycles to observe and worked normal."

They didn't charge me for the inspection since nothing was found.

I was advised to monitor the coolant level.

I did ask the service advisor if the tech heard any rattling bearing noise while working on the truck and he stated no, but I can hear it in the garage while idling.

I guess from here I'm going to just check the coolant weekly and before every long trip and fill the radiator as needed, and listen for that bearing/rattling noise to see if it gets any louder.

I have 100 mile towing on my AAA so if I break down I can always have it towed and fixed at that point in time.

Thanks for all the assistance with this and if anything changes/breaks I will update this thread.

thanks for the update, im haing some similiar issue, here was my post on another thread:


last year i have some major overheating issues coming back from a 2 week trip to sedona, truck ran great the whole trip except when coming back thru phoenix then it started getting bad.

After i got home, replaced the radiator with a high capacity racing radiator from CSF, i replaced the water pump, thermostat,radiator cap and fan clutch.

truck has been running great for a long time. recently have some new axle seals on and the put on about 800 miles in the past month and a half. up now at shaver lake in the sierras. doing some wheeling on local trails.

scangage shows and average of about 188-194 most days when driving.

when wheeling a couple times itll go up to 204 but then settle back down in the 190s.

yesterday went wheeling all day long, towards the later afternoon, the temp gauge would go up to 212 and and then drop back down, a few times it went up to 217 but the dash gauge is still in the normal range with no movement. i would. pause and just see if it would escalate and no the temp would go back down in the 190s.

this morning i popped the hood and noticed the same symptoms as mentioned before with coolant spray from the overflow tank. i checked the radiator and the radiator was still pressurized and air came out, grabbed a jug of coolant, and filled it up, was down a half gallon, while the overflow tank was filled to the brim.

i also removed the hose connecting the two and it was free of debris and clear.

ive also did the gas test in the coolant several months back and no hydrocarbons were present in the coolant. coolant is bright pink and the oil is clear as well.

 

[metramm]

the_josh,

What year is your 4runner? I didn't see it mentioned in your response.

I'm glad that your truck didn't overheat on you when you were wheeling!

Glad I'm not the only one that has experienced a pressurized radiator after being cold and sitting for hours.

You performed more preventive maintenance then even I did. I'm still going to have my water pump replaced in the near future.

If you take it in, or if mine changes for the worse, I will of course update this thread. Maybe between the two of us, we can figure this one out, because as far as I can tell, we might be the first two on the board experiencing these symptoms.

 

[the_josh]

the_josh,



What year is your 4runner? I didn't see it mentioned in your response.



I'm glad that your truck didn't overheat on you when you were wheeling!



Glad I'm not the only one that has experienced a pressurized radiator after being cold and sitting for hours.



You performed more preventive maintenance then even I did. I'm still going to have my water pump replaced in the near future.



If you take it in, or if mine changes for the worse, I will of course update this thread. Maybe between the two of us, we can figure this one out, because as far as I can tell, we might be the first two on the board experiencing these symptoms.

Hey man, it's a 2004 v6, just another update to keep this going as I continue problem solving. After our trip at shaver lake and driving around and such we had a 3.5 hour drive home, drove home no issues at all.

Topped off coolant at home with distilled water.

I replaced the thermostat with a new OEM Toyota unit.

Now this week, we are doing a wheeling trip to big bear lake and I'm towing a trailer (2400lbs)

So yesterday we left mid day, with the trailer, drove 4.5 hours straight to pismp beach, didn't stop at all. Truck drove perfectly fine, temps ranged between 186-197f during the whole trip including hill climbs

Woke up this morning and checked coolant, reservoir was full as "normal" and I topped off the radiator, added probably about 20ozs which I think also included some of the bubbles that's burped out after doing the thermostat since I didn't really drive if after doing that part replacement.

I was going to replaceme my radiator cap and purchased a OEM Toyota one then realized it doesn't fit my CSF aftermarket radiator, so I'm gonna find a replacement STANT brand one that will fit my radiator and match the OEM psi rating.

I kinda doubt that will do much, I'm still confused as to what the issue exactly is.


Also as a side note, back in 2008 I had a head gasket issue on this truck. I was actually one of the very first to document the process on this forum, if not the first. Well the easy fix back then was to just replace the engine. So I dealt with head gasket issues very thoroughly and know all the indications on this engine and everything it did. At this point, I still have not ruled out a head gasket but it needs to make it self known which it hasn't yet, nothing at this point is identifying a head gasket.

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[Warwicke36]

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.

EDIT: Just realized someone resurected a Zombie Thread, I will leave this up for anyone else anyways....


That's what mine did when it needed head gaskets. YMMV. I had no overheating or misfire..just very small unexplained coolant loss and the occasionaly startup waterfall noise through the heater core. Good luck, they're a pain in the ass.

I did my timing chains, waterpump serp belt tensioners and idlers (plus some other stuff) while I was in there. FWIW I had my heads milled .008" with no issues. Definitely get your heads checked and milled if necessary. If you have questions I would be happy to help.

 

[the_josh]

EDIT: Just realized someone resurected a Zombie Thread, I will leave this up for anyone else anyways....





That's what mine did when it needed head gaskets. YMMV. I had no overheating or misfire..just very small unexplained coolant loss and the occasionaly startup waterfall noise through the heater core. Good luck, they're a pain in the ass.



I did my timing chains, waterpump serp belt tensioners and idlers (plus some other stuff) while I was in there. FWIW I had my heads milled .008" with no issues. Definitely get your heads checked and milled if necessary. If you have questions I would be happy to help.

Appreciate the input but the coolant loss In this thread is not unexplained, it's an overflow from the reservoir and not bubbling in the heater core have been experienced

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[Warwicke36]

Appreciate the input but the coolant loss In this thread is not unexplained, it's an overflow from the reservoir and not bubbling in the heater core have been experienced

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OK, I was trying to be helpful. You are choosing to twist my words in a way that wasn't the meaning behind my post. My coolant loss was unexplained (until diagnosed)... Of course there is an explaination, that's the diagnostic part, which is generally what people come here for help with. Which was what I was trying to provide. My situation was SIMILAR but not exactly the same... My exhaust gasses entering the cooling system weren't enough to push coolant out of the reservoir, But overfill it slightly and then not siphon back in due to the loss of vacuum created by the hole in the head gasket.

If you read the whole thread you will see he mentions the waterfall noise behind the dash, which is a classic symptom of a bad head gasket. That is what I was speaking to. As far as "bubbling in the heater core" those are your words not mine. Lastly if you want to come here and jump on my post for reasons unknown on what has already been identified as a zombie thread please make coherent thoughts... the wording of your post makes no sense.