New Volvo 850 Purchase!

[xHeart]

In the absence of owner's manual, keeping one would help https://www.ebay.com/sch/i.html?_from=R ... &_osacat=0

AND, once there was a MVS Maverick named OzarkLee who suggested that in the absence of new bolts, you can clean up threads and use thread locker to avoid down time. Here is tap and die kit for any DIYer:

[foggydogg]

2 thermostat bolts
Part Number: 986228
Supersession(s): 969156

I thought these were known to be a problem?

The point I was making - about the 'points' on the stock t-housing fasteners - was just that issue; corrosion makes them stubborn to remove anyway, and having a torx fastener, with the Crud of Ages down in the hole, makes the removal fraught with danger. The gasket setup on the thermostat is different than what we're used to in Chevy world, there isn't a paper gasket depending on the clamping force of the bolts to keep weep down. While the nice allen-head bolt from Volvo is a very elegant solution, I'm a little gun shy about putting anything with an 'innie' back in that spot. As the Sage of Albany, Abscate, mentions, a light touch is all that's needed, hence my comment about not needing a 10.9 in that application.

[foggydogg]

Manual pdf from the Mother Ship:
https://volvo.custhelp.com/app/manuals/ ... /model/850
Alternate:
https://www.manualslib.com/manual/533742/Volvo-850.html

And to continue the flog on the thermostat issue, you were probably going to chase the threads when you got it apart anyway, based on your Chevy knowledge base. None of the ones I've had apart were very crusty. Torx head was always the issue.

[SirBrickWagon]

welcome to the crew! you'll love volvo ownership, i've been at it a few months now and the car never disappoints!

[abscate]

A Torx screw is a much better fastener than a hex for stripping. The Points that take the load are in compression more than shear and steel doesn’t compress much. If you use a pick and get the Torx tool down well, you will break the fastener before you strip the head

Nickel anti seize is the elixir that will stop the thermostat bolts seizing. Ford makes a nice product

[454cid]

Typical half-baked answer from abscate!!

Glad you found the cup holder. They are not particularly strong so be careful how big a cup you put in it or it ends up on the floor.

Neil.

Yes, I noticed that it didn't look durable. My use will mostly be a 16oz coffee cup, or maybe a 20oz water bottle, so I hope I'll be ok.

[454cid]

The point I was making - about the 'points' on the stock t-housing fasteners - was just that issue; corrosion makes them stubborn to remove anyway, and having a torx fastener, with the Crud of Ages down in the hole, makes the removal fraught with danger.

I'm going to spray some Liquid Wrench on them shortly and get them soaking for a day or two. I'll have access to a compressor when doing the work, and blow out the recesses as best as I can beforehand. If I have to, I may be able to find a fine pick. Thanks for the warning.

The gasket setup on the thermostat is different than what we're used to in Chevy world, there isn't a paper gasket depending on the clamping force of the bolts to keep weep down.

Thankfully, My Gen VI 454 does not use paper. I really hate cleaning old stuck gasket material.

While the nice allen-head bolt from Volvo is a very elegant solution, I'm a little gun shy about putting anything with an 'innie' back in that spot. As the Sage of Albany, Abscate, mentions, a light touch is all that's needed, hence my comment about not needing a 10.9 in that application.

Do the threads go into the coolant passage, or are they blind? That will change what I put on the threads, and possibly what bolts I use.

[454cid]

A Torx screw is a much better fastener than a hex for stripping. The Points that take the load are in compression more than shear and steel doesn’t compress much. If you use a pick and get the Torx tool down well, you will break the fastener before you strip the head

I don't have a lot of experience with Torx, past screw driver sizes. I'll definitely clean the heads out.

Nickel anti seize is the elixir that will stop the thermostat bolts seizing. Ford makes a nice product

I've got some old military surplus stuff that I really like... I did inquire of the company that made it, but they didn't have time to respond to an email that wasn't sales, related, I guess. It doesn't separate like the commonly found Permatex found at parts stores.

It must be that neither of the bolts go all the way through to water?

[abscate]

Blind holes on the thermostat housing , I believe, so don’t go too long

[454cid]

Blind holes on the thermostat housing , I believe, so don’t go too long

If the threads on the originals are fine, I may just re-use them. I just came back in from spraying them with Liquid Wrench, and on the surface they look pretty good. The rear one does have some corrosion, but not to the level I was thinking.

I also put a piece of cardboard in front of the radiator, and that combined with an air temperature slightly above freezing, the needle came up to half way on my short drive, whereas before it was barely coming up at all.

I also pulled the ignition wire cover, found it VERY clean other than the area immediately around the oil fill. I think the oil fill cap gasket is bad. The bottom of the cap has been covered in oil from the cam throwing it, every time I've opened it, and the gasket's not holding it back. I don't think it's a PCV problem, as I don't get air blowing out of it. I've found the gasket on ebay, and IpdUSA.