just purchased one of those obd2 readers
and the code that came up was po128 ( which in the manuel states coolant thermostat (coolant temperature below thermostat regulaing temperature)
cleared the code, not sure if i should of as now the engine light is off
- what does the code mean,,,what should i do,,change thermastat etc
anyone
2002 s40 volvo turbo automatic 90,000 kms

 

See if it comes back.
If it does replace the coolant temp sensor and thermostat.

 

thanks tech
this is probably why ,,the heat was not coming to the drivers side on the feet..also is a big job to change thermostat and sensor and the cost of both
thanks

 

It is pretty easy to do. Follow the upper radiator hose to the engine. It is under that cover that the hose attaches to.

Check out this site for prices.
http://www.swedishpartswholesale.com/

 

HI
where is the coolant temperature sensor located
thanks
-

 

Once you get the top of the thermostat housing off you will see the sensor sticking out of the bottom half of the thermostat housing.

 

HI
erased the code from the obd reader , but noticed today the engine light came back on...so now ...you mentioned replacing both thermastat and sensor...does the code ask to change both or should only change 1 or the other,,,should replace sensor or thermostat? thanks
-

 

I would do both they both fail at about the same time.
You have to remove one to get to the other.
Thats why I say just do both.

 

Thanks tech...just curiuos , even though get heat and the temperature gauge is set at the middle , where it should be...is there a reason why should still replace the thermostat at sensor? thanks

 

if the thermostat is bad it will not let the water flow making engine overheat... if coolent temp censor is bad usually your fan will not work right you will run extremely rich and can cause vehicle to overheat also i just repalced therm on my s80 like 1 hour job make sure to drain water from lower raidiator and make sure car iss cool or you will have a red hand censor runs bout 60-70 $ therm like 35 not to bad very easy replace


P.s. if censor is bad the gauge in car can read incorrect can say middle and actualy be red hot

 

going to volvo soon to pick up parts
for the coolant , doe sit have to be from volvo
was thinking prestone antifreeze, good for all vehicles
thanks

 

does not have to be volvo coolant but would suggest volvo parts i use prestone i think... works fine

 

I am having this same issue. I have purchased a thermostat and tried to install it, but the bolts holding the cover on will not budge. A local shop has said 65 bucks to do it, should I just have them do it or keep trying to get the bolts out? I was also thinking that I should maybe go ahead and get the temp sensor too since the antifreeze is so expensive. The shop said they couldnt put anything except Volvo antifreeze in it, so I bought that today for $33. Any thoughts???

THANKS!

 

Since you already bought the fluid you might as well have them do it.

You can use just about any coolant in there.

 

thanks! would you go ahead and replace the temp sensor too or just the thermostat and hope that takes care of the check engine light?

 

I would do the sensor at the same time.