2002 S60 diagnose a coolant leak ?

butthole · Post by **butthole** » 30 Oct 2014, 18:15

Hi there, so basically the symptoms are:

-bad coolant leak (sometimes multiple litres a day)

-upon a coolant low warning light, turning the air-con to full blast removes the warning for a while (and turning it down again brings back the warning)

-lots of rust residue and colour in expansion tank

-temp has never gone above the middle yet

-alot of the time a dripping is not evident on the floor, however the other day I noticed a lot of fluid dripping from passenger side of engine bay

Post by **abscate** » 30 Oct 2014, 18:57

You have probably blown the heater hose on the back of the engine (RHD)

Stop driving it now, find it and fix..,

butthole · Post by **butthole** » 30 Oct 2014, 20:29

abscate wrote:You have probably blown the heater hose on the back of the engine (RHD)

Stop driving it now, find it and fix..,

It's been driven this way for months lel (friends old car)

butthole · Post by **butthole** » 30 Oct 2014, 20:41

And the bad part is the coolant was regularly replaced with tap water.

Post by **abscate** » 31 Oct 2014, 09:36

And the bad part is the coolant was regularly replaced with tap water.

...which means you now have no coolant at all in your car. This means the boiling point of your liquid is 100C, which can easily be exceeded inside the engine. Every time you drive this car you are pointing a partially loaded gun at it and pulling the trigger.

Post by **precopster** » 31 Oct 2014, 13:33

Gotta agree with the Magnum statement; ; Volvos don't like water as coolant. Boiling occurs every time you drive it and this will over pressurise the cooling system. The small leak becomes a bigger one and the engine is exposed to pockets of air instead of coolant. Don't think that your temp guage will save you; they have a mid guage position range of around 20 deg C. When they overheat they're already at 115 degC and your coolant is nothing more than froth at this temperature.

Put 50/50 mixture back in and this will slow the leak and make it easier to find with the green traces it leaves behind.

draser · Post by **draser** » 31 Oct 2014, 17:54

Being as it may, I'd fix the leak though.

db130 · Post by **db130** » 31 Oct 2014, 18:49

You'll need a coolant pressure tester, like the Stant 12270 kit from Amazon. You'll also need an adaptor for the Volvo's coolant reservoir which part number 12018. With this kit, you'll be able to pressurize the coolant system to simulate a fully warmed up engine, without having to worry about hot scalding coolant possibly hitting you on unfortunate parts of your anatomy.

Post by **precopster** » 31 Oct 2014, 19:41

Be careful with pressure testers. Only pressurise the cooling system to the cap's rated relief pressure of 15psi or just a little more. If you over pressurise the cooling system the next weak link may pop, like seams on the radiator.

butthole · Post by **butthole** » 01 Nov 2014, 03:29

Well I'm beginning to think the sensors gone bad from rust build up or something because it'll bring up the low coolant warning, then I will open the expansion tank while it's still hot in which case it usually over-flows. Okay so next I turn the engine on which stops it overflowing, the level is still above the minimum line. (Speaking of which I realized it's been filled over the maximum line many times.)

I think it does have a leak but it may be more minor than I think (possibly). Can anyone figure out why the warning would go away (atleast for a little while) after turning the air-con (cold) on full?