Cooling Situation...Is This Normal?

[Tachycardic]

I was driving offroad up a 6% grade For 2 miles to get to a trailhead today. Ambient temps were about 92F. I was full-loaded with 7 people and some gear and the AC was blowing.

The AC cut out with another half mile to go, so I assumed that the engine temp hit at least 226F. No smoke or steam from the hood. we made it to the trail head and I checked the engine bay and this is what I found...





After the engine cooled a bit, we continued on our way. AC was blowing fine. This normal? Thanks and happy 4th!

 

[Grandlooser]

You blew up your radiator man. That would be a big fat NO on normal.

 

[ChaseTruck]

Not normal. In the second vid, it looks like the top gasket of your radiator let go.

 

[1911garand]

Totally normal for an overheated engine and failed radiator. $400-700 later - you'll be laughin'.

 

[flintknapper]

Your radiator (top seal at least) is knackered.

So in one respect, yes...it's normal for your coolant to boil over. You lost all the pressure in your cooling system...so the 'boiling point' was lowered to correspond with atmospheric pressure.

But NO..........it's never 'normal' (by design) for your cooling system to boil like a tea kettle.

 

[brockdeck]

Toyota 16400-66081 or Koyorad A1918 available on Amazon

Check for signs of HG failure if you overheated massively

 

[Tachycardic]

I don't have the classic signs of a blown HG. After I let the engine cool, I drove it for another 50 miles to get home and the engine did not overheat--toyocom recorded 186-191F driving home on the highway (105F ambient). Engine power remained good, no white exhaust/smoke, and no leaks.

What could have caused the radiator failure? It was replaced by the PO 8 months ago before I bought the truck, it was working great.

 

[-Spike-]

Failed cap, failed thermostat, lack of airflow to name a few. You pushed the truck harder than normal, and beyond the capabilities of whichever part(s) were faulty.

 

[ccslider]

I don't have the classic signs of a blown HG. After I let the engine cool, I drove it for another 50 miles to get home and the engine did not overheat--toyocom recorded 186-191F driving home on the highway (105F ambient). Engine power remained good, no white exhaust/smoke, and no leaks.

What could have caused the radiator failure? It was replaced by the PO 8 months ago before I bought the truck, it was working great.

Did it have coolant still?

If you lost a lot of coolant the temp sender for the coolant will no longer be reading real engine coolant temperature, you will be reading AIR temp.

 

[flintknapper]

What could have caused the radiator failure? It was replaced by the PO 8 months ago before I bought the truck, it was working great.

Any number of things.

Ranging from poor manufacture (faulty components/assembly) to something else in your cooling SYSTEM.

The last word in the sentence above is an important one to remember. IMO the most often overlooked maintenance duty is the cooling 'system'. It is critical that ALL associated parts be in good working order, as the performance of one often depends on the others.

Your radiator might have been faulty right from the start and just waiting to fail at the least amount of stress. OR your cooling 'system' experienced excessive pressure.

So many things that could cause a build up of pressure (beyond the normal 13-15 psi). But a few (individually or in combination) would be:

1. Low coolant level.
2. Thermostat stuck closed or only partially open.
3. Radiator Cap faulty.
4. Head Gasket failure (manifests in several different ways).
5. Restriction in circulation (hoses, water passages).
6. Ignition timing off.
7. Faulty Fan Clutch.
8. Incorrect coolant mixture (in excess of 50/50).

And the list goes on.

 

[ccslider]

I'd guess the radiator blew up because the head gasket popped and over pressurized the cooling system.

 

[TomH]

I'd guess the radiator blew up because the head gasket popped and over pressurized the cooling system.

That's what happened to mine. My overflow tanked looked like a jacuzzi too.

 

[Ronny Grady]

I bet your engine is fine. My radiator failed the same way. I kept filling it with water every 200 miles, drove home, replaced radiator, hoses, thermostat, fresh coolant, and I was back in action.

 

[Tachycardic]

Did it have coolant still?

If you lost a lot of coolant the temp sender for the coolant will no longer be reading real engine coolant temperature, you will be reading AIR temp.

Yes, I double checked after the engine cooled down. Still have coolant, but interestingly, I have even more more fluid in the reservoir bottle than before. The coolant was filled to the max level, but now I would estimate that it is 80% filled. The thermostat and radiator cap were replaced within the past 3 months with OEM parts, and the timing was put back to 3 degrees BTDC at idle (from 7 degrees)--also about 3 months ago.

I'm hoping that the radiator blew--much cheaper and easier to replace than an HG. But I think what I'm hearing is that the truck is not safe to drive until the issue is resolved (it's my DD). I decided to sell my old DD after driving the truck around for 3 months and not having any issues after base-lining it, and I haven't babied it.

So I guess the question now is, do I replace the radiator and hope it doesn't happen again, or do I check the HG? I'm assuming that a leak detector kit (chemical) won't work since my radiator is shot?

Thanks for the responses all.

 

[TomH]

If the radiator and overflow are bubbling like in your video when the engine is cold then it's a good indication you have a head gasket problem. You may also notice the smell of exhaust coming from the bubbles as they pop.

 

[flintknapper]

Yes, I double checked after the engine cooled down. Still have coolant, but interestingly, I have even more more fluid in the reservoir bottle than before. The coolant was filled to the max level, but now I would estimate that it is 80% filled. The thermostat and radiator cap were replaced within the past 3 months with OEM parts, and the timing was put back to 3 degrees BTDC at idle (from 7 degrees)--also about 3 months ago.

I'm hoping that the radiator blew--much cheaper and easier to replace than an HG. But I think what I'm hearing is that the truck is not safe to drive until the issue is resolved (it's my DD). I decided to sell my old DD after driving the truck around for 3 months and not having any issues after base-lining it, and I haven't babied it.

So I guess the question now is, do I replace the radiator and hope it doesn't happen again, or do I check the HG? I'm assuming that a leak detector kit (chemical) won't work since my radiator is shot?

Thanks for the responses all.

Well.....we know your radiator cap is working (at least one direction) as it let the overflow reservoir accept coolant.

If you start the engine cold with radiator cap off....you should be able to see if there is a constant stream of bubbles (suggesting a head gasket leak to the coolant passage(s). IF you don't see that....then I would suspect the radiator just failed, though you'll want to examine the other components anyway and possibly do some head gasket testing. At the very least...a new radiator is in your future.

 

[baldilocks]

You could also pull the spark plugs and look for the one(s) that has been steam cleaned. Is there any Smokey steam coming from the tail pipe? You can send an oil sample to Blackstone but prior to draining the oil verify the level on the dipstick. If it’s higher than before there may be coolant in the oil pan. And there is always a simple draining and visual inspection of the oil. The fact that engine temp recovered and you drove it 50 miles home without issue tells me the HG is probably fine.

 

[Tachycardic]

Well.....we know your radiator cap is working (at least one direction) as it let the overflow reservoir accept coolant.

If you start the engine cold with radiator cap off....you should be able to see if there is a constant stream of bubbles (suggesting a head gasket leak to the coolant passage(s). IF you don't see that....then I would suspect the radiator just failed, though you'll want to examine the other components anyway and possibly do some head gasket testing. At the very least...a new radiator is in your future.

I just started the truck for the first time today and there were no bubbles in the radiator or in the reservoir tank. I did notice that the coolant levels were low and it took 16 ounces of coolant to get back to normal levels. No smoke coming from the tailpipe. I will probably send an oil sample to Blackstone, and I will pull the spark plugs later.

I'd like to take the truck out to see some petroglyphs today with the family (7 pax). 1000 feet elevation gain on gravel roads, 3-4 degree grades over 6 miles. Expected to be 105F. Go or no go? Thanks!

 

[cartercd]

If the truck breaks down 6 miles from civilization in 105 degree heat what is the contingency plan to keep the 7 people alive? I say no go.

 

[Tachycardic]

We would set up camp (we travel with shelter, food, and water x 1 day for daytrips), and 2 of us would hike back for help. But, point taken thanks!