Hey Guys,

I have a 2008 Volvo XC90 3.2 AWD

In January I changed the water to oil cooler. Since I removed the intake manifold, as a maintenance I took the opportunity to replace also the upper radiator hose and the thermostat.

Check everything and as "always", the coolant temperature gauge temperature reach the middle very fast.

I have been using the car without any problem until this Saturday where I notice that is taking around 25 minutes until the Coolant Temperature Gauge reach the middle.

I am thinking my thermostat is damage and is stick in the open position.

So on Sunday when the engine was cool I checked it again:

I start the engine and leave it at idle. Open the hood and after 5 minute I touch the upper radiator hose an is getting hot…….I touch the lower hose and is cool

I wait 15 minutes until the temperature gauge reached reach 1/4 and I touch the upper radiator hose an is very hot…. touched the lower hose and is a warm

I wait 25 min until the Temperature Gauge reach the middle, I touch the lower hose and its very hot.
What I mean is that is look like the thermostat is behaving correctly.

But I dont understand why the upper hose is hot after 5/10 minutes………

Could it be that my thermostat is not closing complete when is cold and its allowing water to pass.

I dont have any Check Engine Light. I Also read the Car Computer with a LAUNCH OBD Reader and with a Cellphone App and there is not any malfunction code stored

Any Advise?

Thx & Rgds

Isaac

Isaac,

The 3.2 crowd is small here on Freel2

Here are the parts needed for a thermostat change

Note: you can use the Land Rover or Volvo part (I recommend an original Thermostat)

LR006071 - Thermostat

LR001491 - Screw for Thermostat (Qty 4)

LR001442 - Coolant Hose for heat exchanger

LR000491 - Bolt for Heat exchanger hose

LR001505 - O-Ring for heat exchanger hose


My Freel2 3.2 thermostat thread

https://www.freel2.com/forum/topic32245.html

This thread on MVS has more information on 3.2 Thermostats and how they fail

https://www.matthewsvolvosite.com/forums/v...mp;t=86205

I know you post on MVS also

There are more 3.2 owners over there

Good luck

Paul

Hey Paul,

Thx for all the links

I am so off because I put the new thermostat this January.

I think fixing this car is like a hobby

I will order a new thermostat and will be updating this post.

Thx for your time and help

Isaac 2008 Volvo XC90 3.2 AWD

Isaac,

You should get the Thermostat from Land Rover or Volvo.

I know that aftermarket thermostats are available but this part is already a know failure point so I recommend getting an original part.

Having said that did you get an aftermarket Thermostat in January?

If you got an original Thermostat and it failed then I am surprised you would be the first person that reported this.


Good Luck

Paul

Hey Paul

It was a aftermarket one. I think the brand was Eurospare. It comes in a green box.

But I am thinking and thinking what happened...............

My Water to oil cooler was leaking oil into de coolant system. My Coolant reservoir was full of oil. I replaced the water to oil Cooler.... The one that goes joined to the oil filter housing

At the same time since we removed the intake manifold, I took the opportunity to replace the Thermostat, the upper hose and also a small hose that goes to the left of the thermostat

Since there was still oil in the cooling system, we flush several times with a degreaser....... I am thinking that maybe this degreaser damage a rubber part on the thermostat.

I am not sure if this was the problem....... I will order a new thermostat.... When I changed I will check the inside and will let you know.

Rgds

Isaac

Click image to enlarge

Isaac,

That makes more sense now

I think that the degreaser may have attached the plastic on the Thermostat housing and weakened it.

The return spring for the Thermostat is held in place by two small plastic tabs.

If the tabs were weakened then they could break and the thermostat would stop working.


Let us know what you find out when you take it apart.


Thanks

Paul

Well Guys,

Today I took the car to the mechanic to install the new Thermostat. Check the pictures. The bad one has a rubber seal that was out of his position allowing water to pass. That's why my engine was taking like 20 minutes to get to the working temperature.

Check the photo of the new thermostat and you will not see the rubber seal.

I order a REIN Brand Thermostat. it Arrive in a REIN Automotive Parts box but when I was checking, find that is Moto Rad brand. I pay US$52.oo on ebay.

I was checking on ebay for MotoRad Thermostat and the same model, was around US$95.oo

BTW, we do not removed the intake manifold to install the thermostat. There was enough space to work. I will say it took around 30 minutes to install the new one.

Thx

Isaac





 2008 Volvo XC90 3.2 AWD