Can sticking Thermostat be cleaned and re-installed on 2007 XC90 SI6 3.2L like a S70?

GreenMagicMan · Post by **GreenMagicMan** » 19 Feb 2020, 09:13

Hi
I just joined and my first post.
I read about removing and re-installing the all in one ridiculous thermostat housing.
I come from deep Honda background work and think it's ridiculous their thermostat has to be purchased with a complete housing for a lot more cash.
This is a common wear / replacement item so this is.... really ... well rant over for now.
Not my favorite welcome to the Volvo's in general as I've never been around one before.

Anyway, I read for the S series anyway, maybe different engine, that it can be removed and cleaned up / loosened and re-installed.

My thermo is definitely sticking open about 75% of the time. And throwing that CEL code and a garage even said it could be responsible for the 3 different cylinder misfire codes I'm getting as well.

Thank you !

this is the post I read about refurbishing the existing by cleaning and moving the door:
https://www.volvoforums.org.uk/showthread.php?t=199412
It's in the S80 / XC70 2000-2007 forum there but lists it as for 'sealed type' thermostats.

the codes I'm getting on my scan tool:
6 codes found:
P0302
P0303
P0305
P0300
P0455 large emissions leak
P0128 - coolant or thermostat below regulating temp

I threw in a spare Honda gas cap just in case the easiest thing in the world was causing Evap leak, but after clearing codes, that large emissions leak code is back as well.

This car was bought at auction with unknown history and maintenance and 176,000 miles on it. Cosmetically great shape, but it's got it's mech issues!

Post by **jimmy57** » 19 Feb 2020, 10:22

No, the failure is rarely due to it slipping out of place. When they slip out of place the thermostat wax bulb motion pin is moving crooked or the coil spring has failed.
Quality brand units are available for as low as $41.79 and that is the housing and a new ECT sensor. I have replaced several on other makes that are way more than that. Then there are the ones with a water manifold that are hundreds. V6 Honda Accord that I replaced one on with that same brand priced above was a couple dollars more than that. It is also one with integral housing but no ECT sensor.

GreenMagicMan · Post by **GreenMagicMan** » 19 Feb 2020, 14:46

Ok, thank you for the help!!
Good to know. Any place to point me where I might find a unit like that around that price?
I only took fast look at Rock Auto and it was like $80 for what they had on offer.

wanderdüne · Post by **wanderdüne** » 19 Feb 2020, 15:33

https://www.pelicanparts.com/More_Info/ ... at=Y&null=
But I'd just get the Volvo Part:
https://www.pelicanparts.com/More_Info/ ... eepHeader=

Lifetime warranty here: https://www.fcpeuro.com/products/volvo- ... 0-30774489

Lowest price:https://www.rmeuropean.com/Make/PartNum ... h=31355151

Other good sources:
https://www.ipdusa.com/

For Blue Box parts (I use for dealership installs with warranty when I don't/can't do the work)
https://www.volvowholesalepartsdirect.com/
or
https://www.tascaparts.com/auto-parts/volvo

GreenMagicMan · Post by **GreenMagicMan** » 19 Feb 2020, 21:25

Thanks for links!!

GreenMagicMan · Post by **GreenMagicMan** » 04 May 2020, 12:45

Update:
Just did the job today. Was actually not too bad, never even had swear at the process. I bought the Mahle part from the meuropean auto link a member posted above (thanks!). Was about $50 something.

My short DIY - How To - write up:

I did NOT remove the intake - or really anything at all. I actually just went at the Thermo Housing.

-I shielded off what's right below it (alternator??) with a cut up part of a 2 liter bottle. I parked the car on a uphill incline front raised higher on the incline. This helped channel the pouring out coolant onto my plastic shield and then it drained down into a large hand made catch pan below the car. I estimate I lost 2 quarts or more of coolant on this procedure.

-Disconnected the upper radiator hose to the Thermo housing by taking the metal clip out and then using flathead screwdriver to pry out the upper hose (more below related question).

-Disconnected the electrical connector to the ECT temp sensor on the Thermo housing.

-Disconnected the small coolant hose from the Thermo housing by using a 7mm socket with 1/4 extension and ratchet. (a flathead could be used here instead).
I held the lower hose up higher in the engine by pinching it off in between other engine parts to keep it puking more coolant. I likewise bent up and back the upper hose to prevent even more fluid coming out. But it's gonna leak no matter what, especially from the housing area.

- Disconnected the (4) Thermostat housing bolts. I could view the upper two and the lower passenger one through the intake openings above to connect up the T30 Torx bit. I mounted the T30 bit on a 1/4" socket then to the 3 inch 1/4" extension and ratchet. After cracking loose all four bolts - which was easy and not uber tight / no need for PB Blaster etc... - then I removed the ratchet and hand spun out the bolts.
I had to use that same setup to simply feel by hand the 4th bolt head which is lower driver side. With the intake in the way it's impossible to see it - and frankly with it out I think it could not be seen without a mechanic's mirror anyway. Really - it's not hard and didn't take that long to feel the T30 in on the bolt at least 3x to remove and re-install it later.

On my car a plastic tab had broke which released that flat metal bar which holds back the spring. No wonder the T-Stat was not working!!! In fact those parts fell into the engine side and we fished them out with a collapsable mechanic magnet on stick thingee.

As I read elsewhere, when you re-mount the new thermostat housing, it is held away from the ECT / mounting area it goes back into because there is a raised rubber gasket. When you tighten up all 4 mounting bolts that compresses snug back in place correctly.

Because I pulled the metal clamp from the upper radiator hose - to re-install that hose just doesn't want to go back on. Really really tight and you can't whack a hose at the wrong angle with a hammer (!)
I think I will saw off the OEM metal band clamp that gets left behind with the upper hose and then pound back in that rigid plastic piece and then install a normal type of worm clamp back there like most manufacturers use.

GreenMagicMan · Post by **GreenMagicMan** » 04 May 2020, 12:51

Is there any trick get that upper hose back on with the plastic end part still on it? That's the final step in this repair for us today.

GreenMagicMan · Post by **GreenMagicMan** » 04 May 2020, 14:07

Got it! Used some dish soap and warm water a bit of twisting brute force to cram that back on the housing.