Cruiser Down: Tale of Heater T failure on a 100 series (1 Viewer)

[pjabber]

I’m sorry about your troubles on your trip. Your hardship gave me the motivation to change my Ts this afternoon. I’ve been carrying them around for about a year in case I had to do a roadside fix because I assumed mine were done. The previous owner only took it to the Lexus dealer, timing belt was done at 89k miles not too long ago, very fastidious owner.
This is from a ‘06 with 140k miles...

 

[JZinNM]

I was fortunate....while replacing my starter I just BARELY bumped the heater hose with the intake manifold and one of the heater Tee's snapped right in two. I replaced with metal Tee's. It is in fact a quite common issue if they've never been replaced. Glad you got back on the road.

View attachment 2735437
View attachment 2735438

This is the way to go. These tees were failing before the 100 series was even 10 years old. In my opinion, if a part crumbles when you replace it, it was overdue for replacement. I replaced mine with metal tees in 2007.

 

[LC97MD]

I’m sorry about your troubles on your trip. Your hardship gave me the motivation to change my Ts this afternoon. I’ve been carrying them around for about a year in case I had to do a roadside fix because I assumed mine were done. The previous owner only took it to the Lexus dealer, timing belt was done at 89k miles not too long ago, very fastidious owner.
This is from a ‘06 with 140k miles...
View attachment 2735952

Wow, my friend. I’m continuing to learn that the Tees are a no-joke item. Great job on that repair and thanks for the look at that past-its-prime Tee.

 

[medtro]

I actually believe the 283 was a false reading of some kind. I don’t think it got that high. I think at some point (but my eyes weren’t on the scan gauge, the temp skyrocketed).

ScanGauge records Max temperature. Take a picture of the reading before it is overwritten.

 

[LC97MD]

ScanGauge records Max temperature. Take a picture of the reading before it is overwritten.

Unfortunately another “trip” had occurred, I guess (driving into the shop from the lot?) I couldn’t figure out how to go back more than 1 past trip.

 

[LC97MD]

Update:

I write now at 2300 about 80 miles west of Sioux Falls as my wife pulls the last leg to the hotel for the night.

I got the cruiser back late this afternoon, with the Tee replaced, a fresh oil change, fresh Toyota “red” coolant, a new thermostat (scan gauge shows the temp pegged at 195*F now). Compression test shows “160 to 170” (I’d rather have had precise numbers, but that’s what they gave me).

After driving a couple hundred miles this evening, it runs excellent. I’m obsessively looking at the coolant temp but I think I’ve dodged a bullet this time… no offense to anyone from the Rapid City area, but we were happy to put it in the rear view… onward!

 

[medtro]

Unfortunately another “trip” had occurred, I guess (driving into the shop from the lot?) I couldn’t figure out how to go back more than 1 past trip.

You may still have a chance to get previous day Max Temperature.

User Manual: » User Manuals - https://www.scangauge.com/support/user-manuals/

Copy and paste from » ScanGauge II - https://www.scangauge.com/products/scangauge-ii/

Time & Distance Trip Computers​

The ScanGauge includes three trip computers based on time and distance. They include the Current Trip, Today Trip and Previous Day Trip. Each trip computer starts automatically and tracks the following parameters:

• MPG
• Fuel Used
• Max Coolant Temperature
• Miles Driven
• Max RPM
• Hours Driven
• Max MPH
• Average MPH
• Fuel Cost

 

[LC97MD]

You may still have a chance to get previous day Max Temperature.

Copy and paste from » ScanGauge II - https://www.scangauge.com/products/scangauge-ii/

Time & Distance Trip Computers​

The ScanGauge includes three trip computers based on time and distance. They include the Current Trip, Today Trip and Previous Day Trip. Each trip computer starts automatically and tracks the following parameters:

• MPG
• Fuel Used
• Max Coolant Temperature
• Miles Driven
• Max RPM
• Hours Driven
• Max MPH
• Average MPH
• Fuel Cost

Good idea… I just gave it a look and it looks like I missed a good chance. I should’ve done this yesterday. Dammit. Missed a chance to capture some good info there.

When I go to previous day now I see 105*F and .1 miles. I’m guessing the drive from the front of the service door into the bay at Toyota by the service tech. The cruiser sat there until the parts arrived from Kansas City (or maybe until they wanted to do the work, but I’m always the skeptic).

 

[medtro]

Survived 283F in picture would make you more popular here

 

[LC97MD]

Survived 283F in picture would make you more popular here

No joke! I should’ve reached for the iPhone instead. My pulse probably matched that 283 when I looked at the scan gauge! But, as @flintknapper smartly said, that 283 was most certainly some air/steam reading. An experience I hope to never repeat or read about from a fellow ‘mud member.

 

[e9999]

Not quite sure what this steam thing is we're talking about there. Is that supposed to be better somehow? If anything, that could well mean hotter metal because of lesser cooling, I would think. (Sorry.)

 

[LC97MD]

Not quite sure what this steam thing is we're talking about there. Is that supposed to be better somehow? If anything, that could well mean hotter metal because of lesser cooling, I would think. (Sorry.)

Sadly, that makes sense — hotter metal and definitely not better just because it was steam (and not coolant), but somehow this rig weathered the storm.

That 283*F was the last number I saw on the display as I got to the end of the proverbial kill chain. I heard a sound (hard to describe, but not pinging of any kind); asked my wife “do you hear that”; killed the A/C and radio to hear; noticed the check engine light; noticed the insane temp on the scan gauge; panicked; and the engine shut down… all in 5 to 7 or so seconds.

 

[flintknapper]

Not quite sure what this steam thing is we're talking about there. Is that supposed to be better somehow? If anything, that could well mean hotter metal because of lesser cooling, I would think. (Sorry.)

An air pocket with steam *under pressure* can reach very high temps...BUT what matters is how long that temperature is present. I.E. long enough to transfer to the head or block, or just long enough to be picked up by the sensor. My 'guess' is that is what happened in this case *heat was not present long*.

Warping of components or damage to a head gasket is not a given just because a sensor briefly recorded steam/air pocket. When a cooling system is devoid of liquid coolant *none or little circulating* is when rapid heating of the heads will occur.

A system that is just starting to empty itself will still have coolant and possible pockets of air/steam *if open to atmosphere* or radiator not completely full before the event.

 

[JunkCrzr89]

Public Service Announcement for future readers:

 

[BrownAce]

Wish i saw this thread before my Death Valley trip this last weekend.

Saw a small drip under the car, popped the hood, traced the drip to the T, barely touched it with 1 finger and it exploded hot Koolaid in my face.

I was lucky we were at the Furnace Creek visitor center and the guy at the gas station next door gave me a piece of heater hose. I bypassed both Ts and ran it straight into the other side of the engine. Then drove all the back to LA.

Lesson learned, read this thread first!

On a more serious note, some of the crumbled T went down into the coolant inlet on the engine side. How concerned should I be? Just flush it hard after i replace the Ts? They were literally dust. Turned to paste in my hand

 

[AlpineAccess]

Wish i saw this thread before my Death Valley trip this last weekend.

Saw a small drip under the car, popped the hood, traced the drip to the T, barely touched it with 1 finger and it exploded hot Koolaid in my face.

I was lucky we were at the Furnace Creek visitor center and the guy at the gas station next door gave me a piece of heater hose. I bypassed both Ts and ran it straight into the other side of the engine. Then drove all the back to LA.

Lesson learned, read this thread first!

On a more serious note, some of the crumbled T went down into the coolant inlet on the engine side. How concerned should I be? Just flush it hard after i replace the Ts? They were literally dust. Turned to paste in my hand

If they turned to paste that piece that went in will probably do the same - depending on how big of a chunk it is. It shouldn't be a major concern and the reality is at this point, what can you do other than see if it causes an issue. I'd keep an eye on temps for a week or so and if you don't see an issue I'd leave it. If you do see some odd temperatures, bring it in and have it power flushed.

 

[BrownAce]

If they turned to paste that piece that went in will probably do the same - depending on how big of a chunk it is. It shouldn't be a major concern and the reality is at this point, what can you do other than see if it causes an issue. I'd keep an eye on temps for a week or so and if you don't see an issue I'd leave it. If you do see some odd temperatures, bring it in and have it power flushed.

Thanks, that's about the same conclusion i came to.

Going to add 18 inches of heater hose to my tool kit too.

 

[RemyRunner]

So, are these replacement heater tees from Toyota made from more durable plastic than the originals or will they continue to disintegrate as they age? I have purchased new ones to install but wondering if this is just going to be a wear item in a few years?

 

[BrownAce]

So, are these replacement heater tees from Toyota made from more durable plastic than the originals or will they continue to disintegrate as they age? I have purchased new ones to install but wondering if this is just going to be a wear item in a few years?

Maybe someone else knows for sure but I doubt Toyota has changed the part. They do last more than a few years. Mine were 24yo when they failed. I'd just do them when you do hoses. It's sort of an Achilles heal but you could look at rubber parts that way too.

 

[AlpineAccess]

I haven't seen anything about them that shows that Toyota improved on the design. Some folks are putting in brass units. I don't know how they handle reacting to anything in the coolant but can't imagine they are having issues.

The PO of my vehicle had a shop replace them at 100k. I replaced those at 175k (9 years later) and they were still in very good shape (slightly discolored). At 175k I replaced all of the hoses around the T's as well. It looks like these heater T's are just something that should have been added by Toyota to a 90-100k Toyota service interval; but the Toyo engineers likely didn't foresee having this issue.

I pull the radiator and fan shroud when doing a timing belt because it gives me more room and I don't want to damage a radiator over 15 minutes of work and some cooling fluid. I plan to do the heater T's every timing belt simply because it's easy to go the extra mile and do my coolant flush at the same time.

You could also do heater T's every time you do spark plugs.

IMO the plastic holds up great for 10-15 years, but 20 years is just way beyond what it was designed to do. If Toyota had fiber reinforced the plastic or just gone with metal T's this would have solved the issue altogether but those hoses would have become the weak link then.