Cadillac Repair: 2001 caddy deville overheating, old chevys, head gaskets

Question
I have experienced some nerve wrecking overheating problems recently. I had the thermostat and radiator replaced. And it ran fine for awhile with just the temp guage going 1 level above normal frequently but dropping back down to normal after driving. Now it stumbles at idle and lobes like it has a huge cam in it. it also runs all the way hot every couple of days but then runs normal after cooling. Besides  
guage still goes up and down below normal aswell as above normal I'm frustrated please advise

Answer
Hello Tim,

Your description of the problem is very concerning and I would recommend taking the car to a Service center (Not a dealer) with a tech II scanner.

You may be having a computer or related component failing causing the running problem.

I just answered another person on the North Star engine. Not trying to scare you, but these engines dare not run hot. These are not like the old Chevys where you could peg the guage and do no damage.

When overheated, the north star is known for blowing head gaskets and other internal mechanical problems. Get the car looked at by a qualified technician and hopefully there is not damage that you did not figure on.

Good luck!

Rob