Engine: 70: - V70 Coolant Problem - help needed please

Adriansewell · Mar 29th, 2013, 22:09

Hi,

We have a 2004 V70 2.5T. I can see no leaks in the coolant system, but from the max level mark, the coolant level drops say over 3-4 days to below the min level and the coolant light comes on. The temp gauge is bang in the middle all the time so no probs there. The top left rad hose (when looking into engine bay from front) has blown off twice now. The coolant level does not rise back up when the engine cools down, but does rise back when the expansion tank cap is undone to release the pressure from the system. When I do this, I can hear something located below and right of the engine (again when looking into engine bay from front of car) 'relaxing' when the pressure is released. Our local garage have done a sniff test etc for suspected blown head gasket but found nothing. On idle, there are no bubbles in the expansion tank. The heater did fail to heat just before the top hose blew off last time a few weeks ago but after filling coolant system back up, the heater seems fine again.

Any help/advice re coolant system problem would be really appreciated to get this sorted.

cheers.

jgjones095 · Mar 29th, 2013, 22:18

does the pressure cap on the coolant work?

RM955I · Mar 29th, 2013, 22:19

Same thought here....faulty pressure cap on reservoir?

Adriansewell · Mar 29th, 2013, 22:37

Hi, thanks for such promp replies. sorry for sounding dumb, but how would I know if the pressure cap is working or not? it appears to be a sealed unit so if there is a pressure relief valve inside, I can't see or test it. Thanks again.

RM955I · Mar 29th, 2013, 22:44

The green (?) pressure cap on top of the translucent white expansion tank. Don't know if there's a way to test them - for the relatively small outlay it's just a question of replacing them

http://www.google.co.uk/search?q=v70...bd%3B224%3B300

Adriansewell · Mar 29th, 2013, 22:46

cool thanks. will do and see what happens! thanks v much.

RM955I · Mar 29th, 2013, 22:46

Good luck with it - let us know

GrahamBrown1 · Mar 30th, 2013, 23:21

check to see if your cap as warped slightly i had a similar issue no hoses blowing off but mysterious coolant level replaced cap and no issues since

kicku · Mar 31st, 2013, 14:28

If the sniff test were negative does not mean that you are ok.
This mean head with micro cracks or worse main block cracks.
The only way of creating pressure into expansion tank is cracks into head / gasket / main block. Or boiling water but you said the temp gauge is ok.
You'll never see bubbles in the water tank because the cracks are very little. If the cracks were bigger you will see bubbles into water tank, white smoke, difficulty to mantain 800rpm at minimal revs and water vanishing in minutes.

Sorry for my poor english.

RM955I · Mar 31st, 2013, 20:39

If the pressure cap is faulty it will allow the coolant to boil at a lower temperature than pressurised water: water/coolant under pressure has a much higher boiling point - that's why you should never remove the cap when the engine is hot. The sudden drop in pressure will cause the water to boil spraying you with boiling coolant

Mar 29th, 2013, 22:09	#1
Adriansewell New Member Last Online: Apr 26th, 2013 10:52 Join Date: Jul 2011 Location: Leeds	V70 Coolant Problem - help needed please Hi, We have a 2004 V70 2.5T. I can see no leaks in the coolant system, but from the max level mark, the coolant level drops say over 3-4 days to below the min level and the coolant light comes on. The temp gauge is bang in the middle all the time so no probs there. The top left rad hose (when looking into engine bay from front) has blown off twice now. The coolant level does not rise back up when the engine cools down, but does rise back when the expansion tank cap is undone to release the pressure from the system. When I do this, I can hear something located below and right of the engine (again when looking into engine bay from front of car) 'relaxing' when the pressure is released. Our local garage have done a sniff test etc for suspected blown head gasket but found nothing. On idle, there are no bubbles in the expansion tank. The heater did fail to heat just before the top hose blew off last time a few weeks ago but after filling coolant system back up, the heater seems fine again. Any help/advice re coolant system problem would be really appreciated to get this sorted. cheers.

Mar 29th, 2013, 22:18	#2
jgjones095 Master Member Last Online: Feb 28th, 2024 22:04 Join Date: Feb 2013 Location: South wales	does the pressure cap on the coolant work? __________________ Who said Volvos were build to last? 2.4t V70XC Auto 2001 165k D5 185 XC70 M66 2006 202k

Mar 29th, 2013, 22:19	#3
RM955I Premier Member Last Online: Jun 26th, 2022 23:42 Join Date: Mar 2012 Location: Midlands	Same thought here....faulty pressure cap on reservoir? __________________ D5, 205 Phase 3 V70...love the grunt. Previous: 2004 (2005 facelift) 2.4 170

Mar 29th, 2013, 22:44	#5
RM955I Premier Member Last Online: Jun 26th, 2022 23:42 Join Date: Mar 2012 Location: Midlands	The green (?) pressure cap on top of the translucent white expansion tank. Don't know if there's a way to test them - for the relatively small outlay it's just a question of replacing them http://www.google.co.uk/search?q=v70...bd%3B224%3B300 __________________ D5, 205 Phase 3 V70...love the grunt. Previous: 2004 (2005 facelift) 2.4 170

Mar 29th, 2013, 22:46	#7
RM955I Premier Member Last Online: Jun 26th, 2022 23:42 Join Date: Mar 2012 Location: Midlands	Good luck with it - let us know __________________ D5, 205 Phase 3 V70...love the grunt. Previous: 2004 (2005 facelift) 2.4 170 Last edited by RM955I; Mar 29th, 2013 at 22:48.

Mar 29th, 2013, 22:37	#4
Adriansewell New Member Last Online: Apr 26th, 2013 10:52 Join Date: Jul 2011 Location: Leeds	Hi, thanks for such promp replies. sorry for sounding dumb, but how would I know if the pressure cap is working or not? it appears to be a sealed unit so if there is a pressure relief valve inside, I can't see or test it. Thanks again.

Mar 30th, 2013, 23:21	#8
GrahamBrown1 VOC Member Last Online: Today 19:49 Join Date: Feb 2013 Location: North Yorkshire	check to see if your cap as warped slightly i had a similar issue no hoses blowing off but mysterious coolant level replaced cap and no issues since __________________ Previous -03 S40, 04 V70 D5, 04 V70 D5 Sport, 05 V50, 07 S60 D5, 09 V70 D5 R design, 12 XC60 DrivE, 15 V60 D3 Current- 05 XC90 D5 Exec, 12 XC70 D4 AWD Se Lux, 14 S80 D3 Se Lux

Mar 31st, 2013, 14:28	#9
kicku New Member Last Online: Nov 22nd, 2013 16:14 Join Date: Aug 2012 Location: iasi	If the sniff test were negative does not mean that you are ok. This mean head with micro cracks or worse main block cracks. The only way of creating pressure into expansion tank is cracks into head / gasket / main block. Or boiling water but you said the temp gauge is ok. You'll never see bubbles in the water tank because the cracks are very little. If the cracks were bigger you will see bubbles into water tank, white smoke, difficulty to mantain 800rpm at minimal revs and water vanishing in minutes. Sorry for my poor english.

Mar 31st, 2013, 20:39	#10
RM955I Premier Member Last Online: Jun 26th, 2022 23:42 Join Date: Mar 2012 Location: Midlands	If the pressure cap is faulty it will allow the coolant to boil at a lower temperature than pressurised water: water/coolant under pressure has a much higher boiling point - that's why you should never remove the cap when the engine is hot. The sudden drop in pressure will cause the water to boil spraying you with boiling coolant __________________ D5, 205 Phase 3 V70...love the grunt. Previous: 2004 (2005 facelift) 2.4 170

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