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2004 XC90 T6 Broken Thermostat Nipple Upgrade

Help, Advice, Owners' Discussion and DIY Tutorials on Volvo XC90s. The XC90 proved to be very popular, and very good for Volvo's sales numbers, since its introduction in model year 2003 (North America).
songzunhuang
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2004 XC90 T6 Broken Thermostat Nipple Upgrade

Post by songzunhuang »

I just spent a really annoying weekend doing some major updates on the family SUV. I changed the timing belt, waterpump, tensioner, serpentine belt and drive belt pulley (tried - more at the end of this post). As I have read numerous times on the forums, it's just about impossible to get the timing belt cover off without breaking the 90 degree plastic nipple that comes out of the top of your Thermostat housing. Why the heck would you put a thermostat in the timing cam area? WTF! OK, I digress.

So my project was stopped cold when the 90 degree nipple broke. I was able to find a metal replacement from my local auto parts store! It was a URO part#8636779K. The parts store charged me $31, but you can find it online at IPD or FCPEuro for half that. In the picture below you can see the broken black plastic piece with part of it still inside the housing.
Broken.jpg
The first order of business was to get the broken piece out of the housing. I drilled it out and then used a 7mm tap to clean out the threads.
Tapping.jpg
After that, I used some thread sealant on the new metal part and screwed it into the housing. It looks so much better and is so much stronger at this point.
Installed.JPG
However, all was not well. I don't know how the heck you are suppose to get the timing cover on with the 90 degree nipple fitting in the way. It's supposed to go through a hole in the timing cover, but try as I might I couldn't bend the plastic enough to clear the protruding pipe. It seems that you need to remove the ECU unit to get enough clearance to bend the timing cover (the timing cover has got a crease molded into it for the bend). That was just too painful. I just cut a slot in the timing cover with a Razor saw and was done with it. Here is it all nicely in place.
ThruCover.jpg
When you consider the fact that the hose fitting that connects to the nipple will block most of the cutout in the timing cover once it's installed, I don't think I compromised the protective qualities of the cover at all. This "side project" caused me to lose a day and several hours trying to research and figure out what to do. If you are doing your timing belt, just count on upgrading that nipple with a metal one. You'll save yourself a lot of grief.

Also, removing the hose fitting on the nipple is tricky. I struggled with it until it broke off and I could inspect it closely. Here's how to do it.
1. Press the fitting in (towards the engine).
2. Press the two tabs on opposite sides of the fitting. They have horizontal lines molded into it.
3. Pull back while keeping the tabs pressed. It should come right off.

Pressing those two tabs unlocks a plastic piece that hooks on a ridge on the nipple. f I knew this before, I may have been able to save that plastic nipple piece, but I doubt it.

Oh, and that drive belt pulley. I noticed mine had some slight play in it so I ordered a replacement from the parts store. When it arrived they had ordered the entire tensioner assembly! I would have still taken it except I noticed that they new pulley (Gates brand) also had slight play in it too! No way I was going to put that into the car. I'm going to look for an INA brand online. So ends the saga of my major service weekend. Good luck to you all.
Song Huang
www.thehuangs.com
2004 XC90 T6 AWD Ruby red
1998 V70 T5 - Hurt your eyes red
2000 S2000 - the non Volvo
1984 BMW 633CSi - I'm diversifying
songzunhuang
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Re: 2004 XC90 T6 Broken Thermostat Nipple Upgrade

Post by songzunhuang »

Sigh, all is not well in the upgrade.
The new metal replacement part appears to be slightly smaller in diameter than the plastic one it replaced. There's play in the coupler from the expansion tank hose.

After driving about 20 miles today, I noticed that I was down about a quart of coolant. It appears to be leaking from that coupling. I've ordered a new coupling in hopes that it's just a compressed o-ring in the old coupling after all these years, but I'm not completely convinced it's going to work. This is a pressurized system so it'll probably continue to seep out. I'll wait for the new coupling and then we'll see what happens.

I'll report back what I find.
Meanwhile, my little brain wants to think of a better way to completely delete this coupling...
Song Huang
www.thehuangs.com
2004 XC90 T6 AWD Ruby red
1998 V70 T5 - Hurt your eyes red
2000 S2000 - the non Volvo
1984 BMW 633CSi - I'm diversifying
songzunhuang
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Posts: 305
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Re: 2004 XC90 T6 Broken Thermostat Nipple Upgrade

Post by songzunhuang »

Quick update. The metal URO part is not going to work. The diameter is slightly smaller than the plastic one and you cannot get a good seal with the stock expansion hose. I ordered a new expansion hose and fitting and it doesn't work either.

I tried to use 1/4" I.D. fuel tubing and although it can get a seal on the URO metal pipe, I cannot figure out a way to put the timing cover back on with this setup. It's a boondoggle.

I am planning to take all this off and use the brass couplings that I've seen in another thread.

Next weekend, I am changing this all out. Save yourself some time and just do the brass thing.
Song Huang
www.thehuangs.com
2004 XC90 T6 AWD Ruby red
1998 V70 T5 - Hurt your eyes red
2000 S2000 - the non Volvo
1984 BMW 633CSi - I'm diversifying
songzunhuang
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Posts: 305
Joined: Thu Jan 08, 2009 9:04 pm
Year and Model: 98 V70 T5, 2004 XC90
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Re: 2004 XC90 T6 Broken Thermostat Nipple Upgrade

Post by songzunhuang »

For whomever is reading this, I am moving to an all brass setup for this part. I've tried a lot of stuff and have thrown in the towel. I'll have to drain coolant, remove the thermostat, etc. etc. all again to tap and install this new brass setup.

Here's the parts I got from my local Ace Hardware. It cost just over $22 for me.
Parts.JPG
Here's how it looks when it's all assembled.
Assembled.JPG
The nice thing about this brass setup is that the 90 degree brass piece on the left will be installed in the thermostat. You don't have to mess with the protrusion when trying to put on the Timing belt cover. After getting the cover on, you can just screw in the rest of the assembly. Easy!

Also, you'll have to trim the plastic of the timing chain cover. The current hole is not meant for something of this size. I used a razor saw and cut off the protrusion that points toward the engine. This again makes it so much easier to get the timing belt cover on.

This will be my weekend project. I hope this helps someone.
Song Huang
www.thehuangs.com
2004 XC90 T6 AWD Ruby red
1998 V70 T5 - Hurt your eyes red
2000 S2000 - the non Volvo
1984 BMW 633CSi - I'm diversifying
songzunhuang
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Posts: 305
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Year and Model: 98 V70 T5, 2004 XC90
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Re: 2004 XC90 T6 Broken Thermostat Nipple Upgrade

Post by songzunhuang »

It's been thousands of miles and several months and this repair has held up very well. I've checked often and there's not a drop of leakage. I would whole heartedly recommend this fix to anyone. Save yourself tons of pain and just do it!
Song Huang
www.thehuangs.com
2004 XC90 T6 AWD Ruby red
1998 V70 T5 - Hurt your eyes red
2000 S2000 - the non Volvo
1984 BMW 633CSi - I'm diversifying
gstallons
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Re: 2004 XC90 T6 Broken Thermostat Nipple Upgrade

Post by gstallons »

The metal pipe looked like a good idea but made in India quality .
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RickHaleParker
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Re: 2004 XC90 T6 Broken Thermostat Nipple Upgrade

Post by RickHaleParker »

songzunhuang wrote: Thu Jan 29, 2015 9:43 pm Quick update. The metal URO part is not going to work. The diameter is slightly smaller than the plastic one and you cannot get a good seal with the stock expansion hose.
The ÜRO aluminum nipple can be used. Cover the end with 5/16 (8mm) shrink tubing with a 2:1 shrink ratio. Coat with a lubricant and slide hose on until it locks, It will seal. You will need to repeat the is every time you pull the hose off because the shrink tubing tubing comes off with the hose.

If you look at the threads quality and take the under sized diameter in to account. It is dead obvious the ÜRO aluminum nipple is not engineered, it is not machined, it is Plug Molding. Something I have not seen for decades.
1998 C70, B5234T3, 16T, AW50-42, Bosch Motronic 4.4, Special Edition package.
2003 S40, B4204T3, 14T twin scroll AW55-50/51SN, Siemens EMS 2000.
2004 S60R, B8444S TF80 AWD.
2005 XC90 T6 Executive, B6294T, 4T65 AWD, Bosch Motronic 7.0.
songzunhuang
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Year and Model: 98 V70 T5, 2004 XC90
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Re: 2004 XC90 T6 Broken Thermostat Nipple Upgrade

Post by songzunhuang »

Thanks for the idea Rick. Perhaps it'll help others who find themselves in a pickle after purchasing that inferior part.

As for our family car, the wife is still driving it and the more permanent repair has held up extremely well. It's been almost 4 years since this fix was installed and I have not had any problems. You can't ask for more than that.
Song Huang
www.thehuangs.com
2004 XC90 T6 AWD Ruby red
1998 V70 T5 - Hurt your eyes red
2000 S2000 - the non Volvo
1984 BMW 633CSi - I'm diversifying
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RickHaleParker
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Re: 2004 XC90 T6 Broken Thermostat Nipple Upgrade

Post by RickHaleParker »

songzunhuang wrote: Wed Sep 25, 2019 6:51 pm It's been almost 4 years since this fix was installed and I have not had any problems. You can't ask for more
I use the shrink tube solution on my 2005 XC90 T6. I don't foresee any reason it should fail. 🤞
1998 C70, B5234T3, 16T, AW50-42, Bosch Motronic 4.4, Special Edition package.
2003 S40, B4204T3, 14T twin scroll AW55-50/51SN, Siemens EMS 2000.
2004 S60R, B8444S TF80 AWD.
2005 XC90 T6 Executive, B6294T, 4T65 AWD, Bosch Motronic 7.0.
thomascushman
Posts: 7
Joined: Sat Oct 19, 2019 7:34 pm
Year and Model: 2004 Volvo
Location: Tehachapi

Re: 2004 XC90 T6 Broken Thermostat Nipple Upgrade

Post by thomascushman »

Hello guys!

I have recently been cursed or blessed with the purchase of a hardly used 2004 xc90. And by that I mean used hard.

I also broke the elbow off on the thermostat housing. Only after I had just replaced the water pump. After getting all things back together, the outer most belt cover would not quite line up perfectly. Just about a 1/2 inch too low and would not line up and lock in to the 2 upper clips. I went to shimy it up into the right place - very very gingerly - and that's when it jumped upwards and snapped off the elbow. After some very choice and interesting words that would curl an old sailors ears, I tore it all back down and yanked the thermostat housing off. I have drilled out the plastic nipple and cleaned the threads. I want to go back in with a 90 degree male / male elbow threaded on one side and barbed on the other and make to so the hose connects and disconnects and the res tank. My question is - are these threads standard pipe threads on the thermo housing? I can see they are fine thread, but feel like true pipe threads as a bolt will not thread past 1 and 1/2 turns, Like I said I plan on just running the hose through before securing the belt cover. If the nipple hose combo don't Line up perfect, that cover will the likes of my hot knife and it will fit! Thoughts on my idea?

Oh and thanks for posting all the details, I almost wish in hind sight I hadn't read prior, I would have probably broken it off in the first go round and fixed it all at once. But I digress. I'll nickname these problems in the future as having a volvo weekend. Of which it is saturday night of.

Cheers,
Tom
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