Nyloc nuts?
 

Hi All, this may be a stupid question, but are the nyloc nuts that go around the edge of the engine case in any sort of heat range, i,ve seen blue centres ,red centres and yellow centres, the nuts that came off are red, but does it matter as i,ve got new nuts with blue centres in my garage.

As i said it may be a stupid question,but i don,t want to put the engine in the car, to find that when i start it the nyloc nuts melt.
thanks
Rik

I haver only seen Nyloc melt when I use them on the exhaust nuts.
Bruce

Nyloc Nuts
 

I am fairly sure that colour coding is a manufacturer's choice, I don't believe there is any specification.

I have some Nylocs from one manyufacturer that are Black for UNF and Blue for Metric and others that oinly supply white.

I think max operating temperature is 250 degF