Hi All,

Just hoping someone might be able to help, My 2004 1.9d seems to be running to cold. From cold the coolant temperature gauge slowly rises to a central position on the gauge, but then after some time drops back to far cold side of the gauge and stays there for the remainer of any trip.......

I,m thinking thermostat or sender unit, but am unsure of which is most likely to be at fault or if you could tell me i,m completely wrong ??

Any help most appreciated

Rod

 

They both fail pretty often.

 

Don't suspose anyone knows the part numbers and a rough cost, I'm in the UK so an online source for them too would be extremely helpfull.

Cheers for the fast reply tech

Rod

 

Right,

I,ve purchased a thermostat and the sender . But have been unable to locate a workshop manual for the 1.9d v40 ?! Don't suspose you know where i can get one of them ??

I'm not very versed in motor mechanic's but believe changing these parts shouldn't be beyond me if i only knew where they're located ??

Would i be right in thinking the thermostat is in the housing at the end of the hose exiting the rad on the right looking from the front ?? and the sender is the part on the rear ??

Any pointers , pictures or brief discription of how to do this would be much appreciated....

Rod

 

The thermostat should be where the upper radiator hose meets the motor. There should be 2 screws holding the top part to the motor. The sensor is in the lower portion you should see it easy.

 

Guys, a little worried now .......

I've changed out the thermostat and sender. Very straight forward job (but i did have help from a more competent friend). But the problems still there [:@]

After completing the job i took the car for a run, after around 15mins @ 70mph ish the coolant temp gauge simply fell to cool off the scale and stayed there ............. I dont know if this is of interest but from cold the gauge moves to the center of the gauge fairly quickly and stay's there till it falls it NEVER goes above the half mark.

the hose from the rad to thermostat house is hot to touch after warm up and after the gauge falls but the rad stays cold to the touch at all times, i havent managed to get to the hose feeding the rad on the lower left but the plastic side of the rad is cold ......

Could it be an air block ?? Is there any bleed points i should have bleed ??? Is the system self bleeding ??

please help

Rod

 

Usually if it is an air flow problem then it would run hot not cold.
If the radiator is cold to the touch after highway driving something is really wrong. The system isn't flowing properly.

 

tech,

Ambient temp is around 8 to 10 deg C over here at the moment, so not all that warm really i guess. But only last weekend i done nearly 3 hours on the run @ around 70mph to 80mph. This is when the problem rose it's head.

The car is new to me so i'm begining to think i need to get in touch with the garage where i bought it.

But if it were a flow problem in the system surely it would over heated, boiled or something on a run of that length ??

I've got it booked into a local garage now where it can be hooked up to a diagnostic's computer, but thats not till monday. This failing to cold though is really confusing me ........

Thanks for your help

Rod

 

Confuses me as well.
But running cold wouild be from like a flow to low issue. The coolant would be staying in the radiator to long. Or something along those lines.

 

This has happened to me with another car, and it turned out to be the spindle in the water pump. The propeller inside the pump was not relvolving fast enough due to wear on the spindle. This can often happen if the serpintine belt is not correctly adjusted. The extra tension pulls against the spindle wheel which is only made of nylon and the heat generated causes abnormal wear on the spindle. Initially it affects the pump, but eventually the wear will cause a water leak as the seal wears out.
That is my only experience of a cold thermostat reading.
You did do the right thing by eliminating the obvious thermostat and sensor replacement.

 

Thought i should post an update.
I ended up taking the car back to where i purchased it after changing out the thermostat and temp. sender and the fault still remaining with the gauge.
That was last Monday (11th Feb), Yesterday after a number of conversations through the previous week i was informed they've traced the fault to the display panel which houses the temperature gauge.
The gauge cannot be bought as a seperate item, so there having to change out the entire panel.
So far the bill to them is for 18hrs labour and the panel @ £990 which is still to arrive from Volvo HQ as i'm told there not a stock item in the UK ?! So my guess is when fixed this is going to be like a 2k bill OUCH. Just hoping there right and it works correctly after this ...........
Just really pleased this isn't coming out of my pocket

 

Glad there is progress keep us posted of the out come.