Coolant leak at thermostat housing

[87RangerXLTct]

Noticed I have a slow coolant leak at the thermostat housing of my 2.9.
If I remember correctly there was no gasket just an oring that goes around the t stat? Was looking through my toolbox the other day and found a new paper gasket, should I use that instead of the oring? Also should I go with a 195* Tstat, I just put a set of 42 heat range motorcraft spark plugs in it. Think there's a 180* thermostat in it now. Thanks

 

[RonD]

Yes, 190-195deg for thermostat, better MPG, cleaner oil, longer engine life, from S.A.E. research

Rubber o-ring should fit around thermostat edge, so it needs to be there.
You could install paper gasket but not sure it would help.
Put a bead of silicone around housing closer to the edge than thermostat, that should fill in any gaps

 

[lil_Blue_Ford]

I've had issues with those rubber o rings not sealing well enough so I always silicone around the flange too.

Stock for thermostats was 192*, but with cracking heads being a common 2.9 problem, a lot of people were running 180* thermostats and radiators from 4.0L Rangers to reduce the risk of overheating. After cracking a few heads myself, I'm a bit gun shy too.


Sent from my kite using a trebuchet

 

[87RangerXLTct]

Thanks guys, I have the 4.0 radiator in it and the aftermarket world products heads.