Timing belts

i have a 97 deville does it have a timing belt or chain ??? if so when should it be changed???

Check your owner’s manual. Cadillac Northstar engines use two or three timing chains. But, I don’t know if they have service intervals. Your owner’s manual will state if so.

thers is nothing in the owners manuel about timing belts

That is because you have timing chains and they normally do not need to be replaced.

 thank you much appreciated

Is it a V8 Northstar? That Lotus designed engine uses chains. The older pushrod engines also use a timing chain with no service requirement.

thank you very much