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'10 3.6R Outback Limited, 2zr swapped Toyota Yaris track toy, '05 AWD Pontiac Vibe
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395 Posts
Discussion Starter #1
I have a 2010 3.6R that has an unknown and likely very poor maintenance history. It has always seemed to run a bit warmer than I would expect (208-212*F in the summer on the highway and 2010*F at idle in the winter, up to 217*F on long hills mid summer) I have read on this forum of someone loosing coolant instantly from a cracked/failed radiator neck. I am already planning on replacing the Tstat this spring as it has a very slow weep of coolant below it and I was thinking of replacing the radiator as well to avoid this potentially bad failure.

I'm wondering if you guys think the radiator failures like that are common enough to warrant swapping radiators or do they almost always fail by slowly leaking? All of my past Toyota's have had their radiators go bad in a very un drammatic fashion by just showing some dry coolant around one of the plastic end tanks at around the 10 year mark so I have always waited until they go bad before replacing them.

My wife uses this car when she travels for work and isn't as in tune with the car as me, the last thing I want is to have her stranded and an engine fried due to severe and instant loss of coolant while she kept driving.

side note, coolant was completely drained and re filled 25k km's ago by myself when I purchased the OB.
 

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2008 Outback Wagon 2.5i limited
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154 Posts
I swapped mine for an aftermarket one, as preventative, probably when the car was 6 or 7years old. It hard over 100k miles on it and was just starting to look a little iffy down at the bottom where the road debris accumulates. I think I was changing coolant at the time and didn’t want to fail on a trip out of town. It wasn’t terribly expense and gave me peace of mind. I don’t think it’s crazy, myself.
 

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'03 outback limited, '01 Outback Limited, '01 Legacy L wagon, '96 Legacy Brighton wagon
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1,832 Posts
Have you checked to see if there is any of the usual bugs and road debris clogging the radiator core?
 

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'10 3.6R Outback Limited, 2zr swapped Toyota Yaris track toy, '05 AWD Pontiac Vibe
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395 Posts
Discussion Starter #4
Have you checked to see if there is any of the usual bugs and road debris clogging the radiator core?
I checked it and gave it a really good cleaning when I bought the car. I actually found an old piece of cardboard covering a small section of it. It is very clear now with no obstructions
 

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'03 outback limited, '01 Outback Limited, '01 Legacy L wagon, '96 Legacy Brighton wagon
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1,832 Posts
The next thing you could try is to flush it with vinegar. While most Sub owners will fill the radiator with the correct stuff, there are many who will buy whatever for anti-freeze, and then mix it 50/50 with their tap water, which can easily have a lot of lime dissolved in it (especially here in the midwest), that will eventually coat the insides of the tubes.

Here's one way to do it: How to Clean a Car Radiator With Vinegar
 

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2019 Subaru Outback
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200 Posts
I'm not familiar with the radiator on your car, but many radiators of about the same vintage, give or take ten years, literally fall apart at the seams! What I'm talking about is the connection method where the top and bottom portion of the radiator connect to the cooling portion in the middle. It's often some sort of a clamping system with a gasket in-between. So rather than the cooling fins or internal passages, I'd be worried about those portion of the radiator. I also saw a 2000 Toyota 4Runner recently where that top part (made of plastic) was actually starting to deteriorate. So again I would focus there.
 

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2001 VDC/SC One of a Kind
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12,835 Posts
I've had a few radiators that were original at 200k. I've seen some cracked at 100k. The environment the car is in tends to deter or speed up the radiator replacement timeline. If your more comfortable with replacing it, do it.

Check your battery, grounds and alternator. When my H6 temps started to rise it was because the alternator was going stupid and the fans weren't getting enough current. They ran too slow.

Dito the system cleaning if you find deposits in the thermostat housing or aluminum hose connections.

On the weeping coolant; is it from the thermostat housing or the water pump weep hole? Look closely.
 

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'10 3.6R Outback Limited, 2zr swapped Toyota Yaris track toy, '05 AWD Pontiac Vibe
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395 Posts
Discussion Starter #8
I've had a few radiators that were original at 200k. I've seen some cracked at 100k. The environment the car is in tends to deter or speed up the radiator replacement timeline. If your more comfortable with replacing it, do it.

Check your battery, grounds and alternator. When my H6 temps started to rise it was because the alternator was going stupid and the fans weren't getting enough current. They ran too slow.

Dito the system cleaning if you find deposits in the thermostat housing or aluminum hose connections.

On the weeping coolant; is it from the thermostat housing or the water pump weep hole? Look closely.
It appears as dried coolant right at the base of the Tstat housing. It isnt much and my coolant level never drops, but something I noticed when I just did the last oil change.

I thought the water pump was located at the front of the engine? This is why I figured it would be nothing else other than a bad/old tstat gasket.

When I bought the car the coolant was about 700ml low but it was very clean looking and the correct blue color. I have no reason to think the radiator is plugged other than my coolant temps seems to be about 5*F higher than what most others report.

The coolant temp has always ran high (at least higher than my Toyota's) but it has never seemed to be a cause for concern as the highest it ever hit was a long slow hill and it peaked at 217*F which is still a ways away from the boiling point.

I think I'm going to grab an aftermarket new radiator (Denso has worked well for me in the past) and a new Mahle tsat and gasket. It will give me a piece if mind for my wife's long trips as I'm sure it still is the original radiator. There is currently no sign of coolant leaking at the end cap mating points on the radiator.
 

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2008 OB Limited 2.5i, Portland OR USA
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5,156 Posts
I've had a few radiators that were original at 200k. I've seen some cracked at 100k. The environment the car is in tends to deter or speed up the radiator replacement timeline. If your more comfortable with replacing it, do it.
This ^^^^.

There are a number of components like this that fall outside of a factory specified replacement interval. I don't normally replace otherwise serviceable components unless a failure is imminent and will leave you stranded. However, one other measure I also use that might override this bias is the following:
1. Is my vehicle's age and mileage such that I am I likely to be at a point where I am more than half the service life of the vehicle?
2. Is the component in question not likely to last to the end of that service life?
3. Will it strand me if it fails, or at least be very inconvenient if I were on a trip?

If the answer to all three is "yes", then it seems to me a no-brainer to replace it - you'll probably spend the money sooner or later anyway, but only one more time. Doing it this way means you're in control of the process, and it gives you peace of mind. And then you probably won't need to think about it again.

Things that fall in this category for me are:
  • radiator
  • alternator
  • PS pump
  • A/C compressor
  • transmission
  • braking system components
  • suspension components
 

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2019 Subaru Outback
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200 Posts
This ^^^^.

There are a number of components like this that fall outside of a factory specified replacement interval. I don't normally replace otherwise serviceable components unless a failure is imminent and will leave you stranded. However, one other measure I also use that might override this bias is the following:
1. Is my vehicle's age and mileage such that I am I likely to be at a point where I am more than half the service life of the vehicle?
2. Is the component in question not likely to last to the end of that service life?
3. Will it strand me if it fails, or at least be very inconvenient if I were on a trip?
I would add a fourth. Are you doing other work that makes the labor on changing the part less? For many cars that includes changing the water pump when the timing belt is changed. As to this topic it might be changing the radiator when the water pump is changed, depending on the location of the water pump.
 

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2018 3.6R Limited
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121 Posts
I agree with the preventive maintenance advice. My only input is don't skimp and buy cheap parts. My experience is that sometimes you are no better off than if you had left the old one in.
 

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'10 3.6R Outback Limited, 2zr swapped Toyota Yaris track toy, '05 AWD Pontiac Vibe
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395 Posts
Discussion Starter #12
I would add a fourth. Are you doing other work that makes the labor on changing the part less? For many cars that includes changing the water pump when the timing belt is changed. As to this topic it might be changing the radiator when the water pump is changed, depending on the location of the water pump.
I have the 3.6R so no timing belt or regular WP change for me. I already am planning on draining the coolant and replacing the Tstat and gasket due to a slow weep. With that being done a radiator change is only another 20 mins to do at most.

I plan to grab a Denso radiator off roack auto , they are the OEM for toyota and have served me well in the past, but as expensive as OE but not a cheap part either
 

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2018 3.6R Limited
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121 Posts
My '03 Ford Focus had at least 3 plastic cooling system parts that failed on me. One almost stranded me 300 miles from home.
 
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