Hello,

I just replaced the thermostat on my 850 N/A. I had no problem getting the bolts loose and the cover off. Replacing the thermostat took only 5 minutes.

The problem is, one of the bolts will not tighten snugly. The threads seem to be all worn out on the actual housing. It's the rear bolt that holds the cover on.
The one next to the fuel line. I tried switching the bolts to see if it would tighten all the way. And it seems like the threads are just gone..

Has anybody seen this before?

The simplest thing seems to be to buy a whole new housing. But they cost around $100

Is it a pain to install a new housing and keep the existing cover?

Also, should there be a gasket between the housing and housing cover?

I feel like I opened a can of worms for what should have been fairly simple...

Any ideas?


Thanks!

 

The thermostat housing attaches to the head with a paper gasket between.

The top of the thermostat housing bolts to the main housing with 2 bolts.

The thermostat has a gasket which creates the seal between the 2 parts of the thermostat housing.

You can get a thermostat housing from a junk yard car for just a few dollars. The top doesn't need to match, but it won't be any more at the junk yard.

You will likely have to pull the intake manifold to get that housing off. If I were you, I would pull the top back off and run a bolt down there to see if it will grab. If so, install it first, then the front one. If not, go get a couple of new bolts. The video below should show you the replacement bolts.

 

The intake manifold isn't the worst part of the job. To reach the bottom bolt on that housing, you need to remove the accessory bracket. THERE'S a pain in the butt.

 

If you are referring to the bracket that also has the power steering pump, this video will show you how that comes off. Maybe a swivel can get the bottom bolt.

 

You can get a helicoil kit in the size of the cover bolt and replace the threads. That'll be more than enough for a little cover like that. Seriously, it's MUCH easier and you can find many thread sizes. Here's a link to a kit in m7x1. Helicoil 5546 7 Thread Repair Kit 7mm x 1 00 Coarse M7X1 00 | eBay

 

Thanks everyone..

I just picked up some new bolts for it. $1.50 at Home Depot
It fits a little tighter now. The back bolt is still not as tight as I would like though.

I might order that thread repair kit. In the meantime, I think it'll be fine for now.
There was a little steam coming out after I test drove it. But at least its not leaking coolant like it was last night..

 

Well you have options now. If it continues to steam from that area then you do have a small leak and small leaks are the ones that sometimes get forgotten and then take out a head gasket from overheating.
You want to keep an eye on that steam and make sure you're always monitoring your temp gauge and expansion tank level.