DIY: 1998 V70 Thermostat tips/tricks Topic is solved

[xHeart]

The highest point within the assembly, hence, cn90's observation above is pertinent.

[instarx]

Even with a slope how much higher would the valve hole be... 1/32 inch? Consider what that actually means - a tiny bit of additional air is on the wrong side of the thermostat when the engine is off. How could that possibly matter?

Its like worrying that your pocket lint is going to make your truck overweight at the scales.

[cn90]

Even with a slope how much higher would the valve hole be... 1/32 inch? How could that possibly matter? Consider what that actually means - less than a ml of air is on the wrong side of the thermostat when the engine is off.

Its like worrying that your pocket lint is going to make your truck overweight at the scales.

Your argument (where to place the jiggle valve of the tstat) is similar to another argument: "should we prime the new oil filter or not?". Good practice says yes: prime the new oil filter with fresh oil to prevent engine dry start.

I understand your small little points about the location of the jiggle valve but common sense dictates.
I agree with you that in the big scheme of things, it probably makes little difference, but one may run into overheat issue because the tstat, being trapped by a small pocket of air, may fail to open.

If one placesthe jiggle valve facing the engine (instead of facing the rad), a small pocket of air may prevent the tstat from functioning properly.

Anyway, this DIY was written by a seasoned Volvo Mechanic (Bay 13 in Volvospeed):
http://v-olvospeed.com/volvo_repairs_ho ... ement.html

With the top of the housing off you can now see the thermostat and the ECT sensor that is underneath the housing. Notice the little bleeder/swivel valve on the top of the thermostat, ensure when you put the new thermostat in that the little bleeder valve is facing forward.

Picture from Repair Database to show the slope:
Replace thermostat volvo 850 s70 v70 c70 or xc70



Anyway, placing the jiggle valve forward:
- is free: it costs you nothing
- it prevents the unlikely event of overheat
- is a good practice.

So why shy away from it?

[instarx]

This small issue doesn't deserve much more attention. It certainly doesn't hurt to orient it in one direction, just as it doesn't hurt to orient it in any other. But I just can't see how not having the valve to the front could possibly cause a thermostat not to open properly. The belief that it should be oriented a certain way seems to be based on the circular logic that that is the way it should be oriented. lol

[hanzbe420]

Hi CN: Can you explain why you feel it is necessary to align the t-stat bleed hole at the highest point? I didn't pay that much attention to the location of the bleed hole when I replaced mine. Also, another option for the T-45 torx bolts is to use grade 5 hex head bolts, M7 I think they were. I was able to pick these up at OSH because it was Sunday when I did my replacement. Best Regards, SpeedyPete

I understand its use is for to bleed air bubbles out i think.. But i got one from nappa and its nappa brand. And it doesn't have this hole, and i asked the guy and he said no it wont matter ours don't come with them.. So will this matter if i don't have the hole or what?


this is the one i got... http://www.napaonline.com/Catalog/Catal ... 0293260548

i sprayed it with some penetrate like 10 mins ago waiting a little bit for it to warm up a little more and to give it time so they come loose. I also picked up a 10" 3/8" Drive Extension bar, and a t-40 3/8" drive star bit socket. Both duralast brand. They didn't have a longer t40 just had the one attached to the socket and about an inch long t40.

[cn90]

- No bleed hole on tstat: don't worry about it, just install it.
Some people (BMW, Porsche etc. etc.) drill a tiny hole in thermostat for years.
Search google and you will see what I mean.
I don't think you have to do it but just in case you have air lock.

- Avoid the Torx socket because this is exactly how people strip their tstat bolts. Unless you disconnect the fuel line and move it out of the way so the Torx socket have room to "bite" on the bolt.
The long L-shaped Torx keys are the ticket to success, you can buy them at local Advance Autoparts or Autozone.
Napa does not carry these long L-shaped Torx keys.


PS: Clean the inside of the Torx bolts using a tooth pick or sharp tool.
Debris junk does not allow the Torx key to be fully seated ---> stripped Torx bolts.
Tug the Torx key CW a bit to be sure it bites, then CCW to remove the bolts.
If you decide to move the fuel line, use 14-mm and 17-mm wrenches as shown:

[hanzbe420]

i checked it with the extention as soon as i got outside it fit in there just enough to get a nice bite with a 3/8" ill just let it sit a while and be very carefull i am sure it can be done with this. got this stuff at autozone. dunno if they had the keys.

[cn90]

Whatever you do, avoid stripping the bolts AT ALL COST.
Otherwise, you will spend hours trying to get it out, trust me.
Disconnecting the fuel line is very very easy, all it takes is 10 sec.

[hanzbe420]

ok just got in from doing it and i bought a t40 driver bit as stated in previous post. I didn't use the 10" extension. I used the one that came with my craftsman set it was like 3" 3/'8" extension bar with the t40 socket and boom got them off with no problem. I also used the new wd 40 special penatrant, Worked pretty good, But all in all it wasn't that bad and the bolts were on seance stock cause there was a German "Waller" thermostat stamped volvo. But my 1 problem is i drained coolant from the plastic drain underneath the driver side with a 13mm deep socket till it was loose then did it by hand to control the flow. But after i did everything i put the same amount of coolant in that i took out and its pretty much all the way to the top now. So what should i do let a little drain into the bucket and save it and watch it and add more if necessary or just leave it in there to see if it levels out. And i noticed this one didn't come with the hole in it for the air, The one that was in there had the hole with this little piece wiggling in and out of it looks like a one way pressure release valve for the air. So i am kinda worried about this nappa thermostat not having one. Has any one ever used this nappa thermostat 238.

[cn90]

Start the engine, run around the blocks while watching temp gauge.
Make sure the engine is hot, you will need to run it for a good 15-20 min.
Then bring it back to your house, wait for it to cool down.
Add more coolant as needed.
Don't sweat over this thingy.