Engine: D5: Volvo V70 D5 185bhp 2006 Mystery Coolant Leak

[Clan]

Originally Posted by TurboDiesel2006

I removed the rubber elbow hose between the EGR Cooler and the cylinder head and found a small split by the hose clip. I have replaced this hose and (fingers crossed) the leak has stopped.

But when I started the car the cooling fan immediately came on full blast and stays on even when the engine is switched off. The temp gauge went to 1/4 reading and then dropped back to zero. It occasionally flicks up to vertical but drops back to zero after a few seconds. It stays at zero even though the coolant is at 89 degC. Vida tells me the error code is ECM-2000 Engine Coolant Temperature Sensor Signal to Low. Something in the back of my mind says if the MAF sensor is faulty it will give these symptoms. Any advice. Do I just fit a new temp sensor or should I check something else? Thanks

You have probably disturbed or damaged the coolant temperature sender ,

[S60D5-185]

Sounds to me like there is now air in the cooling system following the hose replacement.

Have you bled it?

If not make sure that the heaters are switched on as well because the heater matrix is part of the cooling system.

[Clan]

Originally Posted by S60D5-185

Sounds to me like there is now air in the cooling system following the hose replacement.

Have you bled it?

If not make sure that the heaters are switched on as well because the heater matrix is part of the cooling system.

The system soon self bleeds , just make sure the coolant bottle is full and check it when it cools down in the morning . The heater needs no special treatment as it is flowing coolant all the time the engine is running .

[S60D5-185]

Thanks Clan, when I've done mine in the past, I leave the expansion cap off until the thermostat has opened and recheck level then before fitting the cap.

Learn something every day.👍

[Clan]

Originally Posted by S60D5-185

Thanks Clan, when I've done mine in the past, I leave the expansion cap off until the thermostat has opened and recheck level then before fitting the cap.

Learn something every day.👍

All you need to do is fill it up when idling, over fill the bottle a bit , go for a drive , park it up , top up next morning and done :-)

The new generation cars need a Vacuum system to draw the coolant in due to their complex cooling system ,it works a treat though .

[TurboDiesel2006]

I was a bit sceptical about the Coolant temp Sensor as I hadn't touched anything in that area so I checked it with a multimeter.
With the engine cold and ignition on I am getting 3.35 kOhms resistance across the terminals. Is this withing range?
When I test the supply connector I am getting 0 volts from either pin to a good earth. I would have expected about 5V. Any ideas?
Thanks

[Clan]

Originally Posted by TurboDiesel2006

I was a bit sceptical about the Coolant temp Sensor as I hadn't touched anything in that area so I checked it with a multimeter.
With the engine cold and ignition on I am getting 3.35 kOhms resistance across the terminals. Is this withing range?
When I test the supply connector I am getting 0 volts from either pin to a good earth. I would have expected about 5V. Any ideas?
Thanks

yes thats about right and should be around 200 ohms when up to normal temp .

the temp sensor does not use the body for earth , try a voltmeter across the terminals ...!

[TurboDiesel2006]

I am getting 0 volts across the two terminals of the coolant temperature sensor supply cable with the ignition switched on. So where to look next?

[Clan]

Originally Posted by TurboDiesel2006

I am getting 0 volts across the two terminals of the coolant temperature sensor supply cable with the ignition switched on. So where to look next?

well the wires disappear into the engine loom which goes past where you were working ... see if anything is damaged or displaced .One of the wires could be damaged in the loom .
the wires go into the ECU on the air filter so not a great distance between sensor and ECU ...

[TurboDiesel2006]

Do you know which pin(s) on the ECU go to the coolant temp sensor?