2002 S80 T6 thermostat temperature sensor and temperature gauge

EChem · Post by **EChem** » 07 Aug 2016, 18:04

Hi all:

Replaced my spark plugs last weekend. I did not completely disconnect the turbo tubes, just loosened and moved them to the side to get the cover off to get to the plugs, as I have in the past. Unfortunately, this time, when I got done and went to move the car, had a coolant leak. I had evidently hit the expansion tank bleeder hose (part # 32, Volvo p/n 8642048 in the diagram), and broke the nipple it connects to on the expansion tank. I got a nylon barbed end hose connector, ground down the barbs so I had a tube which fit nicely inside the nipple, glued it with JB Weld plastic epoxy back to the tank. Was Sunday and had to have running for wife to use for work Monday. Hoping for a temporary fix until I got a new replacement expansion tank the next week. Seemed to go well except for when refilled the coolant and started car, another coolant leak. Seems I also broke the plastic nipple (part 19a with no Volvo p/n in the diagram), at the other end of the hose which screws into the thermostat housing (part 17 with no Volvo p/n in the diagram). Strange thing is, my nipple 19a was not straight like is shown, it was a 90 degree right angle and screwed into the housing on the horizontal surface above the thermostat just to the right of the bolt hole at about 10 o'clock of the thermostat. It also sticks through the timing belt cover where the bleeder hose connects to it outside of this cover. It also has a plastic shroud going from about 12 o'clock to 4 o'clock outside of the nipple which is not shown in the diagram, I am assuming to keep coolant from spraying up onto the timing belt in case the nipple fails. I found the nipple at eEuroparts which was a URO 8636779K. Now made of Aluminum, stated original Volvo was plastic, they no longer make. Got expansion tank, bleeder hose, new thermostat/seal, while I was at it and gaskets in front of and behind the housing and got it all together today. Wife took off to go to store and back after 15 minutes as she noticed temp gauge on dash still on cold. I am assuming in doing all of this, I may have broken the wire or pulled out the connector of the temperature sensor (part # 19 of diagram, Volvo p/n 1275548 seems to be for '99-'01 and 8627679 is for '01-'05, which will be for my '02) as I did not disconnect it from housing. Wife made a 50 mile run in the 85 degree heat today wife no problems, no display generated on the DIM. As I am tired, and will take an hour or two to drain coolant, remove turbo tubes, and I hope I can just wiggle the bleeder hose off of the new Al nipple without breaking it to remove the timing belt cover, I am hoping to do this next weekend. My questions are fourfold.

1. I was looking at posts on the site and others from Googling, and some mentioned the temp sensor feeds the temp data to the ECM. Will I cause another problem from lack of temp data being supplied while driving this week before I tear into the problem? Only will be making 10-15 mile jaunts at a time to work, stores.

2. If temp sensor is just not disconnected and I am going to assume wire broken as I don't believe in coincidences such as the gauge happening to go bad. The 8627679 is about $50. Think that is most plausible or should I first spend the $ to diagnose with Volvo.

3. Anyone taken the bleeder hose off of the nipple coming out of the housing without breaking the plastic fitting on the hose? The new Al nipple has 2 rings and the plastic fitting at the end of the hose has 2 slots that the rings snap into but I can't remember any way to release this grip if one has to take it off, as I do.

4. Anyone have any diagram that is like what I have described (right angle nipple, etc.)? I have a copy of VADIS. Haven't used it for awhile, and when I fired it up last week, I got a message that as of 2/2017 it is not supported. Since I am not connected to official Volvo with it (guess that is why I get an error whenever I click on the "Note" link on a diagram, I assume that I will still be able to use it as I now do. As I had to keep my old WIN 98 desktop and have to drag it out to use the software as I could never get it to install on my Win 7 or Vista PC's, I did spend hours a year or 2 ago looking at posts while trying to research purchase of VIDA and the OBDII cable, but couldn't find a definitive place to get a good, working copy. Or if anyone could suggest that...?

Not been a good year for me and my Volvo(s). My 2002 XC70 got rear ended and totaled in January. The plastic oil dipstick pull on my XC70 broke in Jan. when I went to check the oil. My S80's also broke last month, and now these plastic nipples. Volvo must make their plastic parts with a 14 year life

Can't complain about the Volvos. XC70 had 185K and S80 has 254K. For the most part, just routine maintenance costs. Except for when the XC70's oil sump plugged and somehow blew the crank seal last December. $800 bill 1 month before totaled. S80's was sludged up 6 months earlier and was just popping the oil dipstick a couple of times (o-rings on it were a little degraded). But I would have thought the oil fill cap would have bled off pressure before the crank seal blew.

Thanks,
EChem

Cees Klumper · Post by **Cees Klumper** » 07 Aug 2016, 22:41

There are lots of posts here on the nipple problem. My advice is to get a complete Volvo thermostat housing, which will include the proper nipple, a new thermostat, and the temp sensor, all for not much over $100. The metal URO nipple may not fit properly 'snug' to the tube (been there, done that). It's so much fiddly work down there that you want to make sure it's done right. The nipple on my T6 is also angled, not straight. Good luck with getting it in order, I'm no expert but I am pretty sure that coolant temperature is an important input to the ECU's management of the engine, so I'd not recommend driving longer distances without that fixed.

EChem · Post by **EChem** » 08 Aug 2016, 08:31

Dear Cees:

Thanks for the reply. You are correct, the new nipple does not fit snugly in the housing. If you rotate it in fully, the nipple points to 2 o'clock instead of 6 o'clock so the tube could not be connected to it. I was going to put Permatex thread sealer on it before installing, but I wanted to be able to rotate it easily to clear the timing belt cover when I need to remove it again so I wrapped the threads with teflon tape and, at least for now, seems to be sealed as it hasn't leaked. I couldn't find posts in the S80 forum on this. I searched for "thermostat nipple", "hose nipple", expansion tank bleeder hose nipple", "bleeder hose nipple", and got no matches. Do you know what you searched for to find them?

Thanks,
EChem

Cees Klumper · Post by **Cees Klumper** » 09 Aug 2016, 00:43

I actually meant the fit from the nipple to the tube, not so much the fit into the thermostat housing. I don't recall the search term but will have a look. Good that it hasn't leaked, maybe you're fine then.

Cees Klumper · Post by **Cees Klumper** » 09 Aug 2016, 00:47

Here's one, I searched for uro nipple:

https://www.matthewsvolvosite.com/forums ... le#p383695

EChem · Post by **EChem** » 09 Aug 2016, 06:14

Dear Cees:

Thanks

EChem · Post by **EChem** » 18 Sep 2016, 09:24

I got the Euro metal L nipple. Put it on wrapped with electrical tape. Did not notice any coolant leak after driving a week (about 140 miles), so I hope that is fixed. I'll know better shortly as...
Am getting back to looking at my temp gauge problem now. Cees mentioned cutting off some of the protrusion around the hole, but I am thinking of taking my Dremel cut off wheel and slicing a vertical opening down from the thermostat overflow tank bleeder hose hole in the timing belt cover, so if my problem is not a loose sensor connection and I have to replace the sensor next weekend after I get one, it will make it much easier to remove this cover. Any thoughts as to if this would cause a problem?

Late afternoon update:

Checked overflow tank and coolant level good there so looks like no leak. Now that I've said that I will probably have one after I get everything reconnected shortly. Got torn apart. The bleeder hose to the new metal bleeder hose nipple was a @#*+^ to remove. Read the post about pushing it toward block and squeezing the sides with the horizontal lines and pulling straight out but worked at it for the longest time with many different pliers/needle noses and was so happy when I finally got it. However, with the problem now being my temp gauge, following the wire from the sensor underneath the housing I'll be darned if I can trace it all the way back to a connector under there. Some sort of a plastic shroud the cable runs down behind and can't get my hand between it to feel the connector. For anyone who has changed the sensor itself, is the connector easily reachable to connect from under the car? Unfortunately at the moment I have a breakdown of the bones in my right foot, they can take no pressure so getting under the car and rolling around to see is not an option. Was tough enough working from the top from a wheelchair. I was hoping to check the connector to see if I had just pulled it loose when doing the nipple replacement. I'd like to see if that is the problem before buying a new sensor or housing with sensor. I can replace the sensor from the top and then take it to a garage with lift to have them connect it up, if easy from below. Also, the timing belt cover is a $%*&^ to get on correctly. I searched and found the attached PDF which has a link to "Timing Cover Front, Replacing". Does anyone have that link or any hints? I got in on when I replaced the nipple last month, but today i played for 45 min. and could not get it lined up properly. The front edge won't fit flush, I think because the back edge is cocked from the longest length part not being seated correctly.

Thanks,
EChem

Cees Klumper · Post by **Cees Klumper** » 19 Sep 2016, 13:34

Sorry to hear you are having such issues with this, at least good that the nipple-connection is good. From memory, I don't recall having had any issues with connecting the coolant sensor, that that was difficult at all. But it's been a while, and maybe I didn't have an issue because I took off the entire thermostat housing and replaced that and the sensor at the same time; I do recall vaguely that the wiring has to 'snake around' the housing quite a bit, and perhaps connecting it is much easier with the thermostat housing removed, I'm not sure. I don't believe I had to connect it from below the car, I think it was just from the top.
As for the fitting of the cover, all I can think is perhaps those two tabs in the drawing on page 3 of the document you referred to are giving you trouble, in that maybe one of them is slightly bent, not lining up with the slot it's supposed to go into, I do remember fitting mine back into place was a bear as well.
Good luck with the final steps.

EChem · Post by **EChem** » 19 Sep 2016, 20:01

Dear Cees:

I think you are correct, that was what I felt as well, that the 2 tabs are not fitting into there slots properly. No dang room to even see the tab to the back of the cover and even where it goes exactly, it looks like the front tab is there to just sit behind the metal piece sticking up in front of the pulley assembly. Also doesn't help that the lower third of the cover is hinged so it came flop from front to back (toward the pulleys or away from. I think this may also be much easier to get at from the underneath the car to properly position the cover's bottom edge. I think I am going to enlist a second pair of hands (with good legs) next Sunday when I tackle it again. Thanks.

EChem