cooling issues continue

rbrach · Post by **rbrach** » 19 Oct 2006, 01:18

ok sorry to post here again, but you guys have been helpful. I have been getting a coolant temp sensor code, so i got the sensor and a thermostat from volvo. What has been going on is the car will warm up if i leave it sit and idle, but when i drive and some air gets the the radiator the temp drops low depending on how fast i am going. After a few munutes of driving this way, what i think happens is the computer senses this lean condition and then the temp gauge will go to some type of default temperature near the middle, and the radiator electric fan will be on until the car sits long enough or i disconnect the battery. Is this something that anyone has expirenced, does my theory sound correct? I will add that i checked to make sure it was not the fan relay, i also checked the wire and the harness where the sensor plugs in and everything seemed fine. i replaced the coolant temp sensor and nothing changed. When i tried to take the upper t-stat housing off the inner bolt was in so tight that it broke off my torx tool but didnt damage the bolt head that much. I work in the service dept of a dealership and i had a tech briefly try to get it out tonight and it stripped, and did not respond to a vice grip, but in a fear of me not being able to drive home i had him hold off getting the bolt out. I now have a lower t stat housing on the way as a last case resort when when we go to change the t stat. I just want to make sure that this IS the T STAT and am not doing all of this work in a hurry for no reason i will admit i have had a few isues with my s 70 but i love the car. Thanks in advance everyone.

-rbrach

Post by **akitawagon** » 19 Oct 2006, 01:29

It usually is the thermostat that needs replacing when your temperature gauge starts acting goofy. If you haven't already, check out: http://volvospeed.com/Repair/thermect.php

If the head on the 40mm torx screw for your thermostat housing is totally stripped, you might be able to drill out the bad screw and get a replacement screw without having to replace the whole thermostat housing. The inner screw on mine was pretty tight also but I was able to get it off.

Post by **billofdurham** » 19 Oct 2006, 12:27

If you can't shift the stud drill a hole into the centre of it and use a stud extractor. The extractor screws into the hole you have drilled but has a reverse thread, thus removing the stuck stud. The hole you drill depends on the size of the extractor you use. They usually come in sets of assorted sizes.

Bill.