Coolant loss XC90 2009 SE LUX

johncrwales · Mar 6th, 2017, 22:59

We've had this lovely car since almost new - bought as demo model. We've had a slow running saga with coolant loss for several months. The dealer in Shrewsbury looked for a leak and couldn't find one, so recommended having the head off and changing the gasket. OUCH!!
Unfortunately this has not really helped - possibly loss is a bit slower and is certainly unpredictable. Recently it was pressure tested for one hour and no sign of a drop in pressure.
Question: has anyone had problems with the screw top for the coolant header tank? I just wonder if this is leaking when the engine gets hot. Anyone got any bright ideas? It's a lovely car and we want to keep going. Only 170000 miles.
The coolant looks and smells completely normal all the time - no sign of oil emulsion and the engine oil looks very normal. This was always true and the HG replacement was only because they couldn't think of anything else to do.
Thanks to all. John

cheshired5 · Mar 6th, 2017, 23:24

The problem with pressure tests is that they don't test the cap because it's removed to do the pressure test.

You could try removing the seal within the cap then flip it over and reinstall.

It's worth saying though that if your coolant strength is correct, any leak should manifest as a dry, light powdery crystal residue.

Big thumbs down to the dealer for changing the head gasket if it was a guessed last resort.
Surely a compression test and checking for a pressurised expansion tank would have ruled that out as a possibility.

oragex · Mar 7th, 2017, 00:23

Surprised about the head gasket job. Did the dealer measure the compression in each cylinder before the job? If he didn't then it's quite careless. Were the engine head and block inspected for cracks during the job?

Another source of leak can be the cabin heater, it may leak underneath the front carpets. The carpets are rubberized so may stay dry on top, with liquid underneath.

gmonag · Mar 7th, 2017, 10:47

Very unprofessional of the dealer, but typical behaviour!
It is simple to test for hydrocarbons in the coolant and/or perform a compression test to diagnose a blown head gasket.

Mar 6th, 2017, 22:59	#1
johncrwales John Last Online: Aug 3rd, 2023 18:34 Join Date: Mar 2017 Location: Llanrhaeadr ym Mochnant	Coolant loss XC90 2009 SE LUX We've had this lovely car since almost new - bought as demo model. We've had a slow running saga with coolant loss for several months. The dealer in Shrewsbury looked for a leak and couldn't find one, so recommended having the head off and changing the gasket. OUCH!! Unfortunately this has not really helped - possibly loss is a bit slower and is certainly unpredictable. Recently it was pressure tested for one hour and no sign of a drop in pressure. Question: has anyone had problems with the screw top for the coolant header tank? I just wonder if this is leaking when the engine gets hot. Anyone got any bright ideas? It's a lovely car and we want to keep going. Only 170000 miles. The coolant looks and smells completely normal all the time - no sign of oil emulsion and the engine oil looks very normal. This was always true and the HG replacement was only because they couldn't think of anything else to do. Thanks to all. John

Mar 6th, 2017, 23:24	#2
cheshired5 Premier Member Last Online: Dec 26th, 2021 13:42 Join Date: Dec 2013 Location: Crewe	The problem with pressure tests is that they don't test the cap because it's removed to do the pressure test. You could try removing the seal within the cap then flip it over and reinstall. It's worth saying though that if your coolant strength is correct, any leak should manifest as a dry, light powdery crystal residue. Big thumbs down to the dealer for changing the head gasket if it was a guessed last resort. Surely a compression test and checking for a pressurised expansion tank would have ruled that out as a possibility. __________________ 2002 S60 SE D5 Manual 209000 miles

Mar 7th, 2017, 00:23	#3
oragex Premier Member Last Online: Jul 26th, 2021 21:24 Join Date: Jun 2013 Location: Coldnada	Surprised about the head gasket job. Did the dealer measure the compression in each cylinder before the job? If he didn't then it's quite careless. Were the engine head and block inspected for cracks during the job? Another source of leak can be the cabin heater, it may leak underneath the front carpets. The carpets are rubberized so may stay dry on top, with liquid underneath. __________________ Several Volvo Repair Videos https://www.youtube.com/playlist?lis...ECTts0FSVSOT_c

Mar 7th, 2017, 10:47	#4
gmonag Premier Member Last Online: Jan 15th, 2024 17:24 Join Date: Jun 2010 Location: Bury St Edmunds	Very unprofessional of the dealer, but typical behaviour! It is simple to test for hydrocarbons in the coolant and/or perform a compression test to diagnose a blown head gasket. __________________ Greg

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