Well, here I go again!!!! I took the thermostat housing off and ole fumble fingers dropped one of the bolts (the larger of the two) somewhere down the side of the engine. Can't see it anywhere and can't find it on the ground.

Does anyone know what size the bolt is? It appeared to be metric as I used a metric socket to losen it.

Waiting for a response so I can go get one.

Thanks so much.

 

Do you remember what size metric socket you used to remove it ? That wll determine what size metric bolt you need to get.
Example, if you used a 12mm socket to remove the bolt, than you will need a 12 mm bolt.. But, you need to know what the thread "pitch" is.
Metric threads do not come in "fine or course" thread like sae bolts. They are measured in "pitch"
Example, a 12mm bolt could have a 1.75 pitch (standard) or a 1.5 pitch (fine) or even a 1.25 pitch (extra fine) but I doubt it is the 1.25.
More than likely it is the standard pitch. If so, as an example you would be looking for a 12 mm x 1.75 bolt.
The bolt you have left should be the same pitch as the one you dropped.
Lowes or Home Depot carry metric bolts in various sizes. Don't worry about any type of "grade" as metric bolts are not graded like sae. Just get the right size and length...that is the most important .
As far as length, it is also measured in mm. As a guide, 25 mm is right at one inch in length. so a bolt that is 12mm x 1,75 x 12 mm would be a 12 mm bolt, standard thread, about 1/2 inch long.
Grumpaw

 

Went to the local ACE Hardware and for $2.39 I got the bolt I needed. Installed the thermostat, ran up the engine and all is looking good. I had tested the old stat in boiling water and it didn't open at all.