I was planning a 60 mile or so trip earlier and unfortunately I noticed temperature indicator going up.  After pulling over to the side of the road, it looked like the 1997 2.5 was down a lot of coolant.  I stopped at a convenience store and filled up a gallon jug with hot water and poured it in after letting the car cool down.

I checked underneath and sure enough the one inch or so hose coming off the thermostat housing had sprung a leak.  I'm glad I caught it and was still able to drive it back to parking to address it in the morning.  The smaller hoses can be hard to catch; I had one less than finger width go in a 2.2 engine on top of the engine and blew the engine.    More likely in the hot weather we have been having.

The hose looked like it has a curve in it, anyone know the ID on that?  Thanks.  is it the engine coolant bypass hose?

If I duck tape it up will that buy me enough time to pick the part up and install it?

Edited July 14, 20214 yr by ThosL

It is the engine coolant by[rump roast hose.
Duct tape, i woudn.t chance it since you are in a safe place.

O.

Duct tape will not last.  Yes, coolant bypass hose.  It pretty easy any 90 degree hose bend will work.  In total it's about 4" long.  Sorry I don't have the Dia.  I'm in PDX so out of the garage.

Pull it and take it to Subaru or an auto parts store.  They will be able to match it.

if you can't match it, as an emergency measure, see if you can make a bigger 'loop' with straight generic hose. Smallest 3/4 circle that doesn't kink. Tie/support it out of the way with some cord or zipties strung together.....?

like this

 

____(

Edited July 14, 20214 yr by 1 Lucky Texan

Typically listed aftermarket as a bypass hose, but it's actually inline with the heater hose circuit. Crucial to thermostat operation. Since it's such a simple hose with a bend, most parts stores stock one that will fit (sometimes with some trimming).

If not, there are self-adhesive silicone hose repair tapes that work fairly well for emergency repairs. I try to keep a roll in my cars most of the time.

Frankly I think a comparable straight, not molded hose would have served just as well.  Is there any evidence to the contrary?

At any rate, I went down to NAPA in Norwalk after calling them that said that they had the Dayco #87964 in stock which ebay listed as the right part.  Their computer however showed a different part they did not have in stock.  

I worked on the car down the road in a parking space at the library.  Pulling the main hose going into the thermostat is essential.  The hose clamps you get off with pliers can be hard to work with.  I replaced one with a standard hose clamp from NAPA.  I'm not sure I got the orientation of the hose accurately aligned, I have never been good with that sort of thing.  I put in a gallon of Auto Zone antifreeze, I will watch it more closely for future leaks.

Would it be good to spray down other hoses that may have been compromised by oil leaks falling on them?

 

Edited July 14, 20214 yr by ThosL

1 hour ago, ThosL said:

Frankly I think a comparable straight, not molded hose would have served just as well.  Is there any evidence to the contrary?

because of the short distance, standard straight hose will kink (been tried), unless you do like Texan suggested and make a loop to prevent kinking.

If it were me, when you get it home, change all of the coolant hoses, unless you have done that recently. If they’re all basically the same age, you can expect more leaks in the future, especially the oil soaked ones. 

4 hours ago, 88SubGL said:

If it were me, when you get it home, change all of the coolant hoses, unless you have done that recently. If they’re all basically the same age, you can expect more leaks in the future, especially the oil soaked ones. 

The one that blew was the oldest as far as I know and changing all the hoses is just unrealistic unless specific ones show signs of distress.

And that raises the question why most work by mechanics has become after the fact and why it seems mechanics don't look for potential problems?  The alternative to my working on the car was a tow to a mechanic with problems getting my insurance company tow service to do that with typical 2-3 hour waits, with a shop that may not be able to get to the job for several days and a likely $100 plus charge.  

changing the 2-3 largest hoses preemptively makes sense to me as you might severely overheat before getting off the road. Ths smaller ones likely give you enough time before you go dry so, unless they are easy to get to and inexpensive, might just wait until they leak.

Of course your personal situation makes a lot of difference on this type decision. If you rely on a 15-20+ year old car for critical transportation or long distances driving alone,etc. , you would want to address ANY issue that could strand you. maybe even carrying a starter, alt. and fuel pump even......plus tools lol!

 

and repair tape as mentioned, JB-Weld, and other similar repair gear would be good to have with you.

 

Edited July 15, 20214 yr by 1 Lucky Texan

11 hours ago, ThosL said:

And that raises the question why most work by mechanics has become after the fact and why it seems mechanics don't look for potential problems?  

 

Sounds like you need a new mechanic.

I've been working in dealership parts departments for about 10 years, now. And every vehicle gets a thorough inspection, and when necessary, potential failures are communicated/quoted to the customer and any work declined is clearly noted on the repair order for our records and theirs.

18 hours ago, ThosL said:

Dayco #87964 in stock which ebay listed as the right part

 

Not reliable.

I always start with the OEM part number (with the VIN on www.partsouq.com or www.parts.subaru.com). If that's cheap enough, I just buy OEM. Or I use the part number search on RockAuto to look for cross references to aftermarket numbers.

Otherwise, RockAuto has a pretty good application lookup (look for notes, though, as there can be some tricky listings in there). Any parts store lookup. Or, I believe Dayco, Gates and Continental all have pretty good lookups right on their websites.

I'll try to scrutinize the hoses for possible failures and make sure the oil gets soaked off; the major hoses were recent.

 

What are the most caustic substances that degrade hoses?

From the outside oil. It’s hard tell from the outside when a non contaminated hose is bad. They deteriorate from the inside. If the rest are original, I would seriously consider changing them. They’re 24 years old, if I saw the model of your car right.

On 7/14/2021 at 9:57 PM, ThosL said:

changing all the hoses is just unrealistic

no it isnt - there arent that many rubber hoses that would need to be changed, tbh

upper and lower rad hoses, that little one off the thermostat, and maybe a couple other small ones near the throttle body

the one that is unrealistic unless it is showing signs of leakage is the metal one that runs along the top of the block.

 

On 7/15/2021 at 12:34 PM, ThosL said:

I'll try to scrutinize the hoses for possible failures and make sure the oil gets soaked off; the major hoses were recent.

 

What are the most caustic substances that degrade hoses?

Depends on the hose. All hoses have intended fluids. If you use bulk heater hose for PCV, it'll turn to mush. Standard fuel hose is only fuel resistant on the inside, and can't be used submerged in fuel as the outside layers will degrade.

 

But for a coolant hose, fuel would probably be the worst, but oil is not good, either.

^^^ yep,I was gonna say fuel, and maybe ATF - but, it depends on the actual polymer used.

age is a factor too.

when i got the Forester (214K miles and 14+ yrs old) and did my initial maintenance on it (timing, plugs, filters, etc..) the radiator hoses looked and felt fine from the outside, but the lower one was so thin in places you could actually see daylight thru it. i was honestly surprised that it wasn't leaking.

needless to say, it, and the upper, got changed immediately, along with that small one you just dealt with, for the simple fact that it was prudent to do so at that time, while the radiator was drained, and things were accessible.

I also changed out pretty much all of the vacuum lines, most of which were hard as a rock.

My guess is the high heat conditions blew this one;  

 

Considering the heat these engines endure, it is amazing that does not happen more often.

heat and age...

bet that one is about as hard as a rock, too, isn't it?