Another overheating thread, sorry.

[ASUMTNEER]

Just bought a 2001 SR5 with 188k miles. Runs great but I noticed it had green coolant in it after I bought it, so I decided to change it out to pink. I've done a couple of flushes with distilled water and it started overheating on the way home yesterday. When I turned the heater on, it seemed to help bring the needle down. It never did hit the red mark, but came pretty close. Also, it seemed to help when I accelerated.
I went home and checked the radiator and it was low, nothing in the overflow tank either, so I cranked the engine and started slowly filling it back up. I put about 3/4 gallon in before it reached the top and I let it idle until al the bubbles were gone. Drove it in this morning and it started overheating again about 15 minutes into my 20 minute drive. Do I have trapped air in the system somewhere? Bad thermostat? Help is appreciated.

 

[Bad Luck]

Just bought a 2001 SR5 with 188k miles. Runs great but I noticed it had green coolant in it after I bought it, so I decided to change it out to pink. I've done a couple of flushes with distilled water and it started overheating on the way home yesterday. When I turned the heater on, it seemed to help bring the needle down. It never did hit the red mark, but came pretty close. Also, it seemed to help when I accelerated.
I went home and checked the radiator and it was low, nothing in the overflow tank either, so I cranked the engine and started slowly filling it back up. I put about 3/4 gallon in before it reached the top and I let it idle until al the bubbles were gone. Drove it in this morning and it started overheating again about 15 minutes into my 20 minute drive. Do I have trapped air in the system somewhere? Bad thermostat? Help is appreciated.

Sounds like trapped air in the system. These engines are difficult to get all the air out of the system. I recommend getting a Lisle spill free funnel (Lisle 24780 Amazon.com: Lisle 24780 Spill Free Funnel with Standard/GM/VW/Ford Adapters : Everything Else) and using that in combination with parking on an uphill incline. Install the funnel with one or two of the height attachments, add coolant to the funnel, let the engine run with the heat on (and rear heat if you have it), Give the upper radiator hose a squeeze every now and then, then turn the engine off and let it cool down before removing the funnel setup.

EDIT: If you do replace the thermostat make sure the jiggle valve is at the bottom (6 o'clock).

 

[jsnppp]

It could be any number of things, but I would consider thermostat and possibly radiator change unless its obvious they are newish. I know it didn't overheat before, but its just one of those things.

I was in a similar situation. New to me 2002 SR5 with what looked like light yellow/green coolant. I wanted to switch to pink (I went with Zerex for Toyota).

While it was all apart and b/c of the unknowns of a new rig, I changed everything at that time. All coolant hoses, thermostat, radiator. Truck was parked on a slight uphill. I filled it up, opened all the heaters and let it run. I then squeezed the hoses to get rid of bubbles, and filled up more. I then made sure the overflow was up to the mark.

I watched Timmy's video and possibly someone elses too.

Not super helpful reply but it feels like its solvable, but may require going back through it again.

Jason

 

[jgue467]

I'd start with a new OEM radiator cap, if it doesn't work properly, the system cannot cool properly, cheap place to start before the heads get warped.

 

[ASUMTNEER]

I'd start with a new OEM radiator cap, if it doesn't work properly, the system cannot cool properly, cheap place to start before the heads get warped.

I forgot to mention that I did replace the cap with an OEM one to start the process. Thank you for the input.

 

[ASUMTNEER]

Sounds like trapped air in the system. These engines are difficult to get all the air out of the system. I recommend getting a Lisle spill free funnel (Lisle 24780 Amazon.com: Lisle 24780 Spill Free Funnel with Standard/GM/VW/Ford Adapters : Everything Else) and using that in combination with parking on an uphill incline. Install the funnel with one or two of the height attachments, add coolant to the funnel, let the engine run with the heat on (and rear heat if you have it), Give the upper radiator hose a squeeze every now and then, then turn the engine off and let it cool down before removing the funnel setup.

EDIT: If you do replace the thermostat make sure the jiggle valve is at the bottom (6 o'clock).

I ordered an AISIN thermostat and it should be here Friday. I think the radiator is good, but that will be the next item if I can't get it figured out. Went ahead and ordered the funnel. Thanks for the recommendations.

 

[alumarine]

Did it overheat before you changed your coolant?
Is the rad full now?

 

[Bad Luck]

I ordered an AISIN thermostat and it should be here Friday. I think the radiator is good, but that will be the next item if I can't get it figured out. Went ahead and ordered the funnel. Thanks for the recommendations.

You're welcome. Just an FYI the aisin thermostat does not come with a new thermostat gasket.

 

[ASUMTNEER]

Did it overheat before you changed your coolant?
Is the rad full now?

It was not overheating before. The radiator was full last night, I'll go check now.

 

[ASUMTNEER]

You're welcome. Just an FYI the aisin thermostat does not come with a new thermostat gasket.

Just checked ad the rad is not full. No leaks underneath either. It was full last night so i guess I didn't get all of the trapped air out before I capped it off?

 

[19963.4lsr5]

Just checked ad the rad is not full. No leaks underneath either.

Did it suck any coolant out of the expansion tank?

The Rad cap working properly is very important to purging any air out of the system. However, saying that there can be zero coolant leaks. Including the hose to the expansion tank.


Sent from my iPhone using Tapatalk

 

[ASUMTNEER]

Did it suck any coolant out of the expansion tank?

The Rad cap working properly is very important to purging any air out of the system. However, saying that there can be zero coolant leaks. Including the hose to the expansion tank.


Sent from my iPhone using Tapatalk

There's a fair chance I forgot to fill the expansion tank.

 

[ASUMTNEER]

Update

Well, here's a game changer. I went out to my car at lunch and found water running out from under it. t was steady dripping from what I assume is the water pump. No info from PO on TB/WP service. Is the coming from the pump? No signs of water 2 hrs after I got to work, but 4.5 hrs later, I find this leak. Did the engine cool down and allow a seal to contract and weep?

 

[alumarine]

Well, here's a game changer. I went out to my car at lunch and found water running out from under it. t was steady dripping from what I assume is the water pump. No info from PO on TB/WP service. Is the coming from the pump? No signs of water 2 hrs after I got to work, but 4.5 hrs later, I find this leak. Did the engine cool down and allow a seal to contract and weep?

Is it water or coolant?
It's hard to tell from the picture.

To check if it's the water pump you have to pull the top plastic timing belt cover back.

 

[ASUMTNEER]

Is it water or coolant?
It's hard to tell from the picture.

To check if it's the water pump you have to pull the top plastic timing belt cover back.

It's coolant. I'll pull the cover in a few minutes and see what it looks like. It could be coming out of the thermostat housing as well. It's near that general area.

 

[gamefreakgc]

I ordered an AISIN thermostat and it should be here Friday. I think the radiator is good, but that will be the next item if I can't get it figured out. Went ahead and ordered the funnel. Thanks for the recommendations.

The entire cooling system for the engine is as follows, exiting the cylinder heads:

Engine Coolant Temp sensor
Upper radiator hose
Radiator (plus cap)
Lower radiator hose
Thermostat
Water pump

That's the whole system for cooling the engine, minus the fan and fan clutch. The leak is most likely the water pump but could be the thermostat housing. Since you ordered a new thermostat that's the time to check if the leak was coming from there. Do not use any sealant on the thermostat but be sure to use a new gasket as that's what actually seals the housing. If that doesn't fix it assume it's the water pump.

 

[Pyral]

Put some UV dye in the coolant, and use a uv light to see where the fluid is originating. You can get a kit for this at any autopart store and it works well for large leaks

 

[ASUMTNEER]

OK, so I pulled the timing cover and it was dry. The belt and pump actually looked like it has been replaced at some point. The coolant is leaking from back behind the thermostat housing. It looks like a flange of some sort? It doesn't look like it's coming from the actual housing, but whatever it is bolted to behind. Maybe I'm wrong. It may just have to go to the shop.

 

[alumarine]

OK, so I pulled the timing cover and it was dry. The belt and pump actually looked like it has been replaced at some point. The coolant is leaking from back behind the thermostat housing. It looks like a flange of some sort? It doesn't look like it's coming from the actual housing, but whatever it is bolted to behind. Maybe I'm wrong. It may just have to go to the shop.

An oil cooler hose attaches just to the right of the thermostat.
Could be leaking there.

Are the thermostat stud nuts tight?

The thermostat housing and the oil cooler nipple are part of the water pump.

 

[ASUMTNEER]

An oil cooler hose attaches just to the right of the thermostat.
Could be leaking there.

Are the thermostat stud nuts tight?

The thermostat housing and the oil cooler nipple are part of the water pump.

Thanks for this info. It looks to be coming from the oil cooler nipple area (actually where it seals to the head). I have ordered a timing belt and water pump kit and will get it replaced next Wednesday.