Temp Sensor Housing

[Wes]

I am having an issue with the bolts that hold the housing against the head. I cannot seem to get any real purchase on them and fear that the threads have gone.
The bolts that are in there seem to too thin with a bit of side to side play when putting them in.
Has anybody had this issue before?
Any idea on the correct bolt size and thread pitch?
the housing itself looks like it may accept a slightly thicker bolt and if the threads have gone I may need to drill and re-tap the blind hole in the head for a slightly bigger bolt.

 

[Jon Olds]

from memory, m6 by 1
its normal to have extra 'slop' on thermostat housing bolts, too tight and you get corrosion in the gap
Jon

 

[Wes]

Thanks Jon.
Would you not recommend going to a slightly bigger bolt after a drilling and tap or would a helicoil at the standard size be a better option?

 

[Jon Olds]

keep it std. M6 is strong enough, M7 is an oddball, M8 would introduce the 'too tight' bolt to hole clearance that would cause seizure in the future. Coat with copperslip, its never going to be a problem again, most cars have a 15 year window of opportunity for stuff to sieze, from new
Jon