Auto cooling system question

I didn't notice a section for car questions/ problems so I thought I'd try here first. I have a 20 year old Outback that I'm trying to kep running as lomg as I'm able to drive safely. Have always done regular maint. and repairs. On Mon Nov 25 took it in to shop for regular oil change and AAA inspection and everything was ok.
Wed. Nov 27 drove home from errands and some white vapors came out from front of engine. Called the shop where I had the work done. Since they were to be closed till Mon 12/2, the owner came out and diagnosed a coolant leak but no idea where in system. Sat. I took it to one of the oil change shops to see if they could locate the leak and they did and showed it to me They were VERY thorough. Leak caused from a crack in the "coolant bypass cap" a little $4 part, but they couldn't get the right part to fix it. Called the original shop and told him what problem was and what he needed to do about it. He is going to obtain the part but acted like he never heard of it before. I'm sort of wondering if somehow the thing got sabotaged on my original visit so he could try to sell me a new rad. , but the crack leaked too soon. Anyone ever heard of a "coolant bypass cap" before or had any problems with one? Anyone else ever suspicious that garages put time bombs under your hood to set up problems for later? thanks!
 

oldman

Well-known Member
Location
PA
Maybe he is referring to the overflow jug. You should see a small hose running from the radiator to the white jug. He may have taken it off to check the level and either didn’t get the cap on correctly or it may have cracked from the heat of the water against a cold jug.
 

Camper6

Well-known Member
It's good to be suspicious but I don't think it was sabotage.

This is a 20 year old vehicle. You have to expect something with the coolant system. It does get hot. Usually the water pump fails in older vehicles. If the rad was leaking it would be all over your driveway because it would leak even when cool. There is a couple of caps on the cooling system. I'm suspecting the bypass is the one that goes to the expansion overflow tank when the coolant gets hot. What you saw was steam. Maybe it's just what we used to call the radiator cap.
 
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Don M.

Well-known Member
Location
central Missouri
I didn't notice a section for car questions/ problems so I thought I'd try here first. I have a 20 year old Outback that I'm trying to kep running as lomg as I'm able to drive safely. Have always done regular maint. and repairs. On Mon Nov 25 took it in to shop for regular oil change and AAA inspection and everything was ok. Anyone else ever suspicious that garages put time bombs under your hood to set up problems for later? thanks!
If you took your car to a reputable dealer...especially one that has been in business for several years, or you have used before, I doubt that they did anything to "sabotage" your car. If your car is 20 years old, there is a real good chance that many of the Rubber heating hoses, etc., are nearing end of life....and this bypass cap is quite likely just a forewarning of things to come. These rubber hoses/components age, over time, and can fail at any time, leaving you stranded, or with a severely damaged engine, if you try to drive it with a major coolant leak. If you haven't done so in quite some time, you might want to schedule a time with your dealer to replace ALL of the radiator and heater hoses, giving your coolant system a good flush and replacing the Anti-Freeze. Such a repair/maintenance job might cost a couple hundred dollars, but could save you a huge repair bill, and/or needing to replace this vehicle should the engine get overheated and damaged.
 

mike4lorie

Well-known Member
Is it the exact cap for that model, cuz I have a buddy who had an outback, and he couldn't put on any aftermarket parts, and to be Subaru parts. I doubt it, but maybe the mechanic made a mistake and put the wrong one back on yours. Worth a look... I know about the parts, cuz my Buddy who owns one, brought his car down so we could do his brakes... Well howdy, doodie... You need their tools, and exact parts to do the job... Just my 2 cents Buddy! Good Luck with it...
 

Camper6

Well-known Member
Great information here. I hope this becomes a regular topic.

If you can replace the antifreeze yourself you're a better man than me.

It was an easy job in the good old days. Just drain it and run a hose until it's clear and then replace the antif freeze coolant. But no longer. I cant even find the drain plug on the radiator.
 


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