Coolant Leak (2004 V70)

[BobbyC777]

That’s the famous P2 viper.

It’s a down draft tube for the ECU box I believe

viewtopic.php?t=89322&hilit=Mystery+tube

Thanks, @abscate - I'm sure you are correct.

[leapdragon]

So after multiple P80s and P2s, my basic practice at this point is to replace all cooling components every other timing belt. i.e.:

- Water pump (Aisin only!)
- Thermostat unit (including housing) + gasket
- All hoses (2x radiator, 2x reservoir)
- Coolant reservoir
- Radiator
- Heater core

If I didn't do this all myself, it would be hard to stomach as it would cost $$$ at a mechanic I'm sure, but the actual parts themselves for all of the above come to a few hundred dollars for decent (i.e. name brand but not Volvo OEM) parts (Mahle, Behr, Aisin, etc.)

Thing is, sometime between 150k and 200k these things start to fail. My experience with a couple cars was that first the lower radiator hose bursts. You get that fixed and then you're likely to get coolant reservoir, radiator, and/or heater core (in no particular order) in quick succession as you fix them one by one. And each time you have to get a tow as all the coolant got dumped (in the case of the heater core, inside the car!).

You get tired of that... And you start just replace the lot. The water pump is every other timing belt, which generally works out to every 150k miles if you're like me, so in the end I just make it part of my "150k service"... Timing belt (for the second time), idler, tensioner, and the entire cooling system, along with alternator (which also seems to go somewhere between 150k and 200k).

Some would say why bother if it's not failed yet, but you make it all up on tow costs alone in my experience and this stuff isn't particularly hard to do on the P2 cars (radiator is the worst, but still not too, too bad compared to a lot of other cars). It's a couple Saturdays worth of work.

But even if you're having someone else do the work, it might be worth it to bite the bullet and have them replace all the bits and pieces if you're up over 200k. These radiators and heater cores in particular all WILL fail at some point and when they do, it's a PITA. Radiator because it feels really risky (unlike a burst hose, these tend to dump all the coolant without notifying you via steam or a loud noise; you just have to detect that your coolant light has come on before you fry your head!) and even if/when you catch it in time before damage has been done, it means a tow and usually the shop has to order one in from afar and you're left waiting, heater core because it tends to get antifreeze all over your interior...

[BobbyC777]

@leapdragon
Thanks so much for the detailed response and advice. If I had a proper shop and extra car I might have the courage to tackle all this but I have neither. <sigh> And putting a couple of thousand $ into a 21 year old (230K mi.) car is something I'd have to think long & hard about. Of course, the option (a newer car) would cost even more. Thanks again!

[abscate]

Topping off once per month? Just drive it.

Two scenarios

If you have a sane commute, top off until it reaches the one week top off frequency mark, then you can start looking at end caps of radiator and decide if you want to deal with it. P2 cooling systems are a lot more robust than P80, Ive found.

If your commute is crazy, high miles, the economics of repair are easier. Driving 500 miles per week costs you 50 (self) or 100 (paid) a week in repair and maintenance, and 150 a week in depreciation of a new car, so its an easy choice.

[BobbyC777]

Abscate -

I like your logic! I've been thinking along those same lines - just drive it. I don't want family pet getting into any anti-freeze so I have some cardboard down and at this point it's only a couple of drops which is easily absorbed. And I'm keeping our critter out of the garage as a safety measure. Thanks for the counsel !

[jonesg]

so you didn't find the leak yet ?
this is the time of your I decide whether I can limp through winter with delayed repairs or get it done.

[BobbyC777]

so you didn't find the leak yet ?
this is the time of your I decide whether I can limp through winter with delayed repairs or get it done.

Nope, it's pretty small and I mostly see traces on outside of ECU vent tube. It could just be expansion tank. At this point I can live with topping off coolant once a month or so. Thx.

[BobbyC777]

Thx - that would be nice if it was the reservoir. BTW I have never been able to release the tab that connects the coolant reservoir to the power steering reservoir. I have tried and tried!

flat screwdriver blade, they usually snap off anyway, even my new one broke.

Anybody ever removed the coolant reservoir as easily as this? Not me !
https://youtu.be/pRzIpsAXbhQ?si=zav9nev3A76x651T&t=49

[abscate]

Sure,you snap off the tabs in the dead of winter by looking set them, then put a big zip tie around the cooling and PS reservoir!

[jonesg]

Thx - that would be nice if it was the reservoir. BTW I have never been able to release the tab that connects the coolant reservoir to the power steering reservoir. I have tried and tried!

flat screwdriver blade, they usually snap off anyway, even my new one broke.

Anybody ever removed the coolant reservoir as easily as this? Not me !
https://youtu.be/pRzIpsAXbhQ?si=zav9nev3A76x651T&t=49

Those videos are staged but thats the method, I just jam the 2 tanks back in position and they've never moved in 8 yrs.
I blew my old volvo engine playing coolant roulette so I'm cautious.
Oil leaks, power steering leak meh...