Troubleshooting Overheating - What Next? (1 Viewer)

[incudie]

Hey All,

After some recent maintenance I'm fighting issues with engine over heating. Coolant temp shot up to 239 while driving the other day after having been on the road for most of the afternoon.

Since then I've given some love to the cooling system, I run in the 190s while moving but as soon as I idle, the temperature creeps up past 210. Coolant heats up even faster with no apparent upper limit when AC is on. At the moment, I’m unable to safely drive the vehicle without watching coolant temp like a hawk.

Here are some details I've put together:

Maintenance History:

• Radiator and hoses replaced 54,000 miles ago with “Liland” aluminum.
• Water pump/gasket replaced 54,000 miles ago with OEM.
• FAN Clutch/Thermostat replaced 54,000 miles ago with AISN
• Replaced Heater-Ts with brass connector 54,0000 miles ago.
• Flushed coolant and used 50/50 Toyota Red 54,0000 miles ago.

Problem recently started after I:

• Replaced Starter
• Replaced gaskets for coolant at inlet/outlet at rear of engine coming from heater-Ts.
• Having fuel injectors serviced.
• Had intake manifold cleaned and replaced gaskets.

In response to overheating I have:

• Replaced thermostat with OEM

1. Coolant hoses hot, coolant seems to be circulating.
2. Heater on full blasts hot air and helps bring coolant temp down. This tells me the water pump is okay?

• Fan Clutch:

1. After driving for awhile and shutting the car off, fan stops spinning within 1 second. Tells me fan clutch is okay?
2. No free play in fan.

• Burped with cap open and ran engine at 2400 RPM with heaters wide open.

1. Attempted multiple times and drove with heat open.

• Replaced Radiator cap.
• Drained coolant at radiator and flushed through a few gallons of distilled water (ran the car, drained). Refilled with “Peak” brand pink concentrate blended to 70/30 with distilled water.
• AC Fan appears to start/stop correctly.

Next up to try:

* Replace vacuum hoses and clamps. They seem to be crusty and falling apart. Not sure if this is related.


If anyone has any recommendations on other things to check/try I would really appreciate any guidance.

Thanks!

 

[yngmrostrvile]

Where did you clock the tstat bleed valve? 12 o'clock?

 

[incudie]

Where did you clock the tstat bleed valve? 12 o'clock?

Yes, old one was in the correct position as is the new one. I should also note, the orientation is correct as indicated in FSM. (pointy part of tstat facing outward)

 

[yngmrostrvile]

Some here have indicated having to park on an incline to help the system burp after service. Have you used IR to get temp readings at different points?

 

[incudie]

Some here have indicated having to park on an incline to help the system burp after service. Have you used IR to get temp readings at different points?

Not an IR tool. I did put the truck on jack stands though to do the 'burb'.

 

[yngmrostrvile]

IR temp guns are cheap especially with the lingering vid. Worth while checking to help find an air pocket that wont work past the tstat

 

[incudie]

IR temp guns are cheap especially with the lingering vid. Worth while checking to help find an air pocket that wont work past the tstat

I'll give it a shot and see if I can find an air bubble.

 

[Trunk Monkey]

There's a tool you may be able to rent from an auto parts store that pulls vacuum on the entire system, down to collapsing hoses, and then on release pulls from a outside tank to fill. Pretty much guarantees no air pockets, works great.

I'd look at the radiator, since it's not OEM. Did the coolant react with the material and a bunch of crud has built up inside it?

 

[JunkCrzr89]

I run in the 190s while moving but as soon as I idle, the temperature creeps up past 210.

This is spot-on fan clutch symptom.

FAN Clutch/Thermostat replaced 54,000 miles ago with AISN

Certainly not out of the realm of possibilities that fan clutch has malfunctioned. We know that the Aisin clutches come from the factory with too low of oil type in them (3k I think, when 10k would be better), and are often under filled if you live in warm climate.

 

[Mike NXP]

Based on your symptoms my opinion is going to be something belt/fan/ or dirty radiator related.

The system cools properly when in motion and then gets hot when stopping. So something isn't pushing that heat away like it should. I don't think any focus should be put on worrying about air in the system.

>>When you cold start the engine that fan should roar. When cold and the belt is off it should spin sorta easily by hand. When hot and belt is off it shouldn't spin much ( like you described)

Any chance the radiator is packed with debris down low, it's hard to see sometimes ?

 

[incudie]

Based on your symptoms my opinion is going to be something belt/fan/ or dirty radiator related.

The system cools properly when in motion and then gets hot when stopping. So something isn't pushing that heat away like it should. I don't think any focus should be put on worrying about air in the system.

>>When you cold start the engine that fan should roar. When cold and the belt is off it should spin sorta easily by hand. When hot and belt is off it shouldn't spin much ( like you described)

Any chance the radiator is packed with debris down low, it's hard to see sometimes ?

You might be on to something.

How caked does this look to you?

As you can notice, I'm missing part of the shroud (have for many years).

 

[Mike NXP]

You might be on to something.

How caked does this look to you?

As you can notice, I'm missing part of the shroud (have for many years).

View attachment 3041348

Seen worse but I'd say that would be the next area of interest. Especially since you don't have the shroud down there.

Be gentle with it and try to clean it up. Hose water and maybe some soft nylon brushing will do the trick .
More info here
>>Radiator fins need cleaning! Alert Alert Alert - https://forum.ih8mud.com/threads/radiator-fins-need-cleaning-alert-alert-alert.1151006/

 

[JunkCrzr89]

You might be on to something.

How caked does this look to you?

As you can notice, I'm missing part of the shroud (have for many years).

View attachment 3041348

Yeah that’s not great. Plus with a gaping hole in the shroud like that, the fan is not pulling air through the radiator to cool the coolant.

 

[incudie]

I gave both sides of the radiator a thorough cleaning and there's definitely some improvement but still getting dangerously hot at idle. Coolant hit 214 today while sitting in traffic (with AC on). It's also quite hot here in Austin, TX.

I feel like it's got to be related to the starter job I just did. Maybe I've got a leak somewhere and the PSI isn't getting what it should be.

Would seepage through older hose clamps cause this kind of high heat?
I could go through and put hose clamps on everything.

 

[JunkCrzr89]

I gave both sides of the radiator a thorough cleaning and there's definitely some improvement but still getting dangerously hot at idle. Coolant hit 214 today while sitting in traffic (with AC on). It's also quite hot here in Austin, TX.

I feel like it's got to be related to the starter job I just did. Maybe I've got a leak somewhere and the PSI isn't getting what it should be.

Would seepage through older hose clamps cause this kind of high heat?
I could go through and put hose clamps on everything.

Old leaky hoses or a gasket leak somewhere, etc. But the fact that the truck cools down while driving but heats back up at idle = air flow through radiator problem. That busted shroud is a major problem. I’m guessing you probably don’t have a bit of foam around the front edges of the radiator either, do you?

 

[incudie]

Old leaky hoses or a gasket leak somewhere, etc. But the fact that the truck cools down while driving but heats back up at idle = air flow through radiator problem. That busted shroud is a major problem. I’m guessing you probably don’t have a bit of foam around the front edges of the radiator either, do you?

Probably no foam if it comes attached to the OEM radiator. Looks like I can use something from HomeDepot though since Toyota doesn't sell it. Any tips on placement/type of foam?

I agree the shroud needs to be replaced and foam needs to be added but I've never had this kind of issue until after doing the starter job.

Thanks for your help!

*edit* I'm getting a replacement shroud either way.

 

[JunkCrzr89]

I've never had this kind of issue until after doing the starter job.

Could be coincidence. Could be something else. But there’s enough wrong with the radiator + shroud + fan that air flow is insufficient to help cool the coolant. You have enough coolant in the system?

 

[wengejor]

I saw a video on how to check for exhaust gasses in the coolant. You might see if you have a head gasket leaking.


I have experienced the burp issue in other land cruisers. It ran fine for months around town after radiator work, then on a long highway run the bubbles made their way past the sensor which caused brief and scary high readings.

 

[Mike NXP]

Probably no foam if it comes attached to the OEM radiator. Looks like I can use something from HomeDepot though since Toyota doesn't sell it. Any tips on placement/type of foam?

I agree the shroud needs to be replaced and foam needs to be added but I've never had this kind of issue until after doing the starter job.

Thanks for your help!

*edit* I'm getting a replacement shroud either way.

I was able to purchase new foam recently although I stuck it to my oem skid plate . Suppose it would have made more sense to stick it to the frame above.

I can't imagine what you would have screwed up with your starter job they would be making this happen. If something is leaking you would see it and the fluid level would be low. What else might have happened , aren't there some electrical connections down in the engine valley related to cooling ?

 

[JunkCrzr89]

What else might have happened , aren't there some electrical connections down in the engine valley related to cooling ?

Knock sensors are in there. But I suppose the ECT sensor by the throttle body could’ve been damaged when removing the intake manifold, which could cause temps to rise.