3.2 Thermostat & Coolant Temperatura Gauge

Turbo_Boss · Post by **Turbo_Boss** » 07 Sep 2020, 15:58

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

chitownV · Post by **chitownV** » 07 Sep 2020, 16:37

I posted this in the other forum where you asked the same question.

Hi Turbo_Boss,

You might have already diagnosed your issue. Not knowing what brand of thermostat, but it might be the thermostat assembly with sensor. And you could be right that it is sticking, either semi or fully, open.

Assuming you changed the entire thermostat assembly, including the coolant sensor, double check the coolant sensor connection. Next, what I would do since you are in a hot climate, would be to replace the thermostat assembly with a good brand. Unfortunately, some cheap parts are cheap and damage while shipping can happen to parts from a good company. There aren't many other moving or electronic parts in the cooling system besides the water pump.

What coolant did you use? Asking in case there is any issue with caking or interaction with the coolant temp sensor.

Post by **pgill** » 07 Sep 2020, 21:52

Isaac,

I posted this on FREEL2 for you but I want to include it here for MVS readers

This post has some detail about how the Thermostat works

viewtopic.php?f=31&t=86205

Let us know what you ultimately find out

Thanks

Paul

Turbo_Boss · Post by **Turbo_Boss** » 09 Sep 2020, 19:59

Hey Guys,

I will bite the bullet and order a new thermostat..... This car is a money pit

I will be updating this post with what I found on the bad thermostat.

Cheers

Isaac

Turbo_Boss · Post by **Turbo_Boss** » 03 Oct 2020, 15:00

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

Post by **oragex** » 03 Oct 2020, 15:26

Not to be pessimistic but I googled https://www.google.com/search?client=fi ... good+forum
Big brands always outsource some of their parts. Rein is good (OEM) for some parts, but since they try to 'cover' more of the market, they may have to outsource parts from various companies that may not always be at the standard of Rein. Same is happening now with Lemforder, they are selling horrific strut bearings totally made in some obscure chinese factory (failure within 2-3 months).
Ebay is usually the risky to buy anything other than big components like a clutch kit or a branded shock absorber. Not to mention the counterfeit. Fcpeuro or Eeuroparts.com (may have better shipping fees at international) have the best brands out there but they also sell bad brands like Professional Parts Sweden (or Proparts), Meyle, Febi and so on. Some even Made in Germany, but no quality. The parts market is Wild, we need to know what to buy (may ask us for advice)

Turbo_Boss · Post by **Turbo_Boss** » 04 Oct 2020, 09:11

Hey Oragex

Thx for your comments

The thermostat came in a box that have the REIN Brand, made in Israel ... I Hope this will last long

Today parts even if it says MADE IN GERMANY, it is not a sign that is good quality. I imagine that they have also lowered their quality in order to compete with China.

Rgds

Isaac