Xc90 D5 coolant leak, pipes ok, fluid on block
 

Hello all,

I wonder if anyone can help? Our 54 plate D5 has started loosing coolant. Been ok up until last week then it started dropping and now using about half a pint every 3 days. Pipes look fine but I have noticed blue coolant low down on the engine block. I'm not expert but it looks too for the head gasket. It seems to be weeping from the gasket but why is coolant down by the sump?

Any ideas?

Many thanks,
Sam

Firstly, remove the timing cover and check all around the coolant pump which should be bone dry.

Just what I was thinking, my money is on water pump - any water loss in cars I have owned with head gasket problems has always been via the cylinders so have seen an engine leaking water from a head gasket down the block.
Could it be a leaking core plug?

Thanks.

I will check tonight. Any idea of cost of water pump replacement? Is it a big job?

Sam

If it is the waterpump ( quite unusual on a Volvo if original ). you may as well do the whole cambelt and auxiliary belt as well because the waterpump is driven by the cambelt.

Unless it has all been changed VERY recently, it makes sense to kill two birds with one stone .


If you are handy with the spanners then all of this is very DIY doable.:teeth_smile:

Sounds promising. Can you do it without lifting the car? Only have a drive and won't work underneath on jacks. I could buy axle stands I suppose if it helps.
Sam

No special gear at all although the crank pulley is at 300nm so you will need a high torque impact gun if removing crank pulley.

I always use good axle stands and leave a trolley jack in situ as well for additional safety.


You remove the front offside wheel, peel back the inner arch liner once the retaining bolts have been removed and you will see the crank pulley.


Volvo quote an hour to do a cambelt change and that is entirely possible.


I've changed the belt on both my XC70 D5 and my XC90 D5 but both times the waterpump was left untouched as it was perfect. The access to the pump from this stage is pretty decent.


Contrary to popular belief, the belt can be changed with the crank pulley in situ but obviously it is an easier job if removed.


See here for Cheshired5 video

+ YouTube Video

View of Waterpump change

+ YouTube Video

Thanks. Do you have to drain the coolant before removing the pump?

Not sure how coolant would get to the front of the engine from a leaking water pump though, as it seems to be near the back.

I would take the plastic belt covers off and try to ascertain where it's coming from for certain before taking the pump off.

Also, without being funny, make sure that you are entirely comfortable with how to change the belt because if you get the timing wrong or install the belt incorrectly your engine will be toast.

It's not complicated BUT you have to be methodical and accurate with your work.

Also check for a pinhole leak in the radiator top hose and around the thermostat housing.
With correct coolant strength, there should be dried, white crystallised residue from the leak source.

I'll admit that the coolant pump is unlikely because of the journey the coolant would need to make to where it is gathering but given the unusual location of the problem, just check all bases.