Coolant leak

[Tee5alive]

Hi folks

I have had a leak that has been difficult to trace, not head gasket (as no yoghurt in the engine) not radiator. I suspected tje expansion tank was split so replaced this but STILL leaking. So one last try to spot the leak with fluorescent dye in the water system. This revealed a small suspect area under ultra violet light, in the hose going into the expansion tank at the bottom.

I have been unable to locate the correct part however to order one. Can anyone help please

The model is a 2003 V70 D5 SE AUTO 2.3.

Thank you

[Dangerous Dave]

Try www.skandix.de/en enter your model and chassis number then look for radiator hoses.

I've had a look but there are various options so it's best to put your chassis number in to get a more accurate part list.

This should get you a part number to work with.

[MoleT-5R]

Coolant leaks.....don't get me started on those, I killed two engines in separate vehicles within a couple of weeks of each other by not attending to them straight away, I look at a small weep in a very different way now.

[Dangerous Dave]

Two engines Adrian?

[MoleT-5R]

Two engines Adrian?

Gul killed its head gasket when the rad failed and filled the turbo with water and the xc90 seized it's water pump and popped the timing belt off, Gul is now just going back together after an engine swap and should be running again later today

[Dangerous Dave]

Gul killed its head gasket when the rad failed and filled the turbo with water and the xc90 seized it's water pump and popped the timing belt off, Gul is now just going back together after an engine swap and should be running again later today
OH no, not the XC too!

And good to hear Gul is fixed (ready for the next Wales run :) ).

[Tee5alive]

Sadly it is tunring into a mystery leak. Some days she loses water others not. Putting paper underneath NOT ONE DRIP so where is the water going? I replaced the expansion tank (my mistake as I got chinky knock off) which leaked out of the cap so bought a genuine VOLVO TANK. I put fluorescent dye leak finder in it and STILL no sign of water OTHER than blowing back through the exapnsion tank. The rad is like new, no yoghurt in the engine and BAGS of grunt so not a head gasket, no bubbles in the expansion tank. Performance is normal now ive done a fuel sysytem and injector clean and currently running her on a tank of 'the expensive stuff' i.e. not the usual 'red diesel' the cheap garages sell!

I looked at it with one of the guys from work and we reckon the ONLY thing left is the thermostat not opening fully so a new one was bought today and TRYING to fit in the pouring rain! The reason is...................... the return pipe is ROCK SOLID after a long run usually you can squeeze this pipe, leading me to suspect a faulty thermostat, pressurising one side of the system?

I thought i kew these cars but this one is a mystery - well I hope I fix it tomorrow as Im back to Devon! Otherwise Ive got to drive down in my T5..................no not a V70...................this is a VW VAN! Not comfy as shes GUTTED waiting for me to insulate and fit wiring and solar panels for the camper conversion!

[MoleT-5R]

When you say the return pipe is rock solid, you will probably find that the outlet spigot on the thermostat housing as corroded up blocking the return, it's a stupidly small bore tbh, why I don't know, I was temped to bore mine out and bit when it was off but then I thought there must be a reason Volvo made it that size. Water leaks are very annoying especially if the come and go, does this depend on how far your have been, i.e. if you do short trips nothing is lost, but long journeys you notice a loss..?

[Tee5alive]

well when I first got the car it would 'seem' to do about 30 miles then need topping up, but now the DIM warning comes on after just sitting outside the house idling?

I have just changed the thermostat assemly the whole alloy unit with temp sender etc and initially it seem to have cured it. Went to turn the car off (after an hour running on leak test) and the 'LOW COOLANT LEVEL STOP SAFELY' was on again!!!

The symptoms are it seems to suck all the water out of the expansion tank giving the 'low coolant' warning, then as it cools it returns to the tank? AS I said before NO HINT of a leak ANYWHERE. I have fluorescent dye in there and a UV light I can check with. The ONLY place I have found theis dye is BELOW the expansion tank after blowing some out of the tank BUT the temp guage NEVER goes above normal.

The radiator is hot all over so thats fine
NO YOGHURT in the oil or filler cap so thats fine
NO OIL IN THE COOLANT so not head gasket
PERFORMANCE as normal so same conclusion
HEATER working perfect
carpets dry inside SO not a heater matrix leak
I have BRIGHT YELLOW DYE MARKER in the coolant system and NO TRACE in the exhaist pipe or inside the engine oil cap so assume head gasket is intact.
As the performance is, shall we say, spritely........I doubt head gasket or can I be wrong?
SO
WTF is leaking??????

NEVER one instance of it overheating but the fans never seem to kick in, my VIDA is dead atm SO I cannot check fan funston.

I even tried a can of BARS LEAKS which didnt NADA! But WHERE DID IT GO??? not one drip under the engine?

I am on my FOURTH V70 so I THOUGHT I knew these cars well but THIS has me pulling out my hair (if I had any so metaphorical!)

I CANNOT now use the car to get to Devon and back without stopping at EVERY SERVICES and putting water in - now I can see why the bloke sold it cheap.:rolleyes: He told me 'Im selling it as it is losing water but I cant tell where'
ME all cocky " thats ok I'll sort it, easy fix"
FAMOUS last words duuuhh.

[uqj83l]

How sure are you it’s not ending up in the auto transmission via the cooler in the radiator?

[Tee5alive]

Ahh well no change in gear shifts and I think water in there would be wrecking those? Is there a level check for the transmission?

[Tee5alive]

Ahh well no change in gear shifts and I think water in there would be wrecking those? I havent checked that yet surely there would be ATF then in the expansion tank?

[MoleT-5R]

Only word of warning if running the car with a water leak and just possibly topping up with water, untill a point at which you can get it fixed..! I've just killed two Volvo's, with my attitude of just pour water in till the parts arrive and I get a day to fix it.....oh no two dead Volvo's. We forget that the anti-freeze is also a pump lubricant so just topping up is nearly as bad as not topping up at all and as for the other one, ignoring a leaking rad only can be done for a short time, but it picking the time I'm late, pushing on and then for it to totally fail, dump the complete coolant spelt disaster again. Although these issue's are to be expected in 25 year old vehicles, these really caught me off guard tbh

[Tee5alive]

Only word of warning if running the car with a water leak and just possibly topping up with water, untill a point at which you can get it fixed..! I've just killed two Volvo's, with my attitude of just pour water in till the parts arrive and I get a day to fix it.....oh no two dead Volvo's. We forget that the anti-freeze is also a pump lubricant so just topping up is nearly as bad as not topping up at all and as for the other one, ignoring a leaking rad only can be done for a short time, but it picking the time I'm late, pushing on and then for it to totally fail, dump the complete coolant spelt disaster again. Although these issue's are to be expected in 25 year old vehicles, these really caught me off guard tbh

Thanks mate weather permitting ill pull the dipstick and check for whipped cream!

FRIDAY UPDATE:

ok Ive dipped the transmission and found NO WATER whatsoever in the ATF. It is going dark red so Im going to drain and refill (if anyone can tell me the right fluid plz?)
SO I guess the only thing left is to replace the radiator? This is getting costly.

[uqj83l]

Good thing the transmission fluid looks ok. The radiators have a tendency to leak in the bottom corners. I think trans fluid is JWS 3309 compliant, but double check as transmissions changed through the years.
I think Nissens make an aftermarket OE quality radiator. Again memory fades after time!

[Tee5alive]

Thanks for that mate

Well after topping up the coolant then a real HELL of a test drive including sitting on the motorway for hours in a big post accident jam - not ONE warning light!

So the leak appears to have been something to do with either the thermostat or temperature sensor as the new part has both pre fitted! So tomorrow need to put antifreeze back in her and she can begin her life with me!

[MoleT-5R]

Glad you've got it sorted, just get the volvo coolant in there asap, I learnt the hard way, I would make that mistake again.

[Tee5alive]

Glad you've got it sorted, just get the volvo coolant in there asap, I learnt the hard way, I would make that mistake again.

Ive put anti freeze in is there a specific 'Volvo' one?

[LeeT5]

I've put anti freeze in is there a specific 'Volvo' one?

To answer your question, yes......

https://www.ebay.co.uk/itm/202456103425

You Sir, have been extremely lucky! I'm going to say this without flowering it up, for the benefit of anyone else reading this thread that may be looking for advice on how to 'correctly' diagnose a coolant leak on a car, no matter how big or small the leak, they should all be treated with the upmost seriousness.

All you did was throw parts at the car and second guess 'what could be wrong'. As Adrian has said, a few times, even the smallest of leaks, if ignored, kill cars!

Coolant IS made up of many components and as said, serves as a lubricant for the pump - so NEVER fill your car with plain water more than once. Even if it's a small leak, topping up dilutes the coolant mix and potentially damages the pump.
Coolant, mixed at 50% water 50 % Coolant, will also raise the boiling point of water by around 5*C. So, filing your car with plain tap water or distilled (doesn't matter which) will mean your engine is more likely to overheat - assuming everything else is working as it should!
A partially seized open thermostat will NOT cause any water loss..FACT!
A seized shut thermostat will very quickly cause the engine to overheat, so driving 30 miles will certainly not be attainable, especially sitting in motorway traffic.
A correctly operating expansion tank cap will further raise the boiling point by as much as 8*C by allowing the system to pressurize. This, further prevent's the coolant from boiling and turning to a gas (which will get trapped in the water pump and cause lack of circulation).
The water pumps job is to circulate the coolant - it does not pressurise the system.
Looking for 'Mayonnaise' or 'Yogurt' in a cooling system will tell you nothing, unless there's 100% of the stuff and no coolant. Emulsion can be present in a header tank (In minute amounts) and more evident in the rocker cover and Oil filler cap in a perfectly working engine. This merely indicates that the driver is doing too many short journeys and condensation is building up due to the engine never being driven for long enough to evaporate the moisture. When the condensation drips down off the rocker cover, it mixes with the Oil and causes the 'Mayo' and 'Yogurt' to be present. Certain Make /models suffer this phenomenon and is made worse by a blocked breather system.
Many people fall into this trap when buying a second hand car. They undo the oil filler cap and see mayo, suck through their back teeth and say 'Oohh, looks like the head gasket is gone!'.....then walk away. :slap:

The only way to correctly diagnose a potential coolant leak (big or small) is with a Sniffer test kit (this is to determine head gasket damage or not) and a Cooling system pressure test kit. This can be used to pressurize the system cold, static, monitor correct pressure increase with a running engine, check operation of the water pump and diagnose if the Expansion tank cap is leaking or not - an often overlooked but very common failure point! If the cap does not hold pressure, then you WILL lose coolant via the overflow (if fitted) or bypassing the cap seal. This will then look like a leaking header tank or associated pipework attached to the tank.

Don't get me wrong Tee5Alive, I am super happy for you that you've hopefully fixed the issue, but you went about it the wrong way, risking the engine in the process.

Always seek professional advice from your local garage with regards to coolant loss, especially if you do not understand how the cooling system works. You risk injuring yourself too as faulty cooling systems can be a real menace and extremely volatile.

Stay safe people! :wavey: