How can you tell if your head gasket is blown.

Here is the prob. I was driving home one day the temp gauge was fine said like 190 ... Just the normal temp. But when I got home it seemed really hot, So i let it sit for a while then when and started it. It kinda idles rough every now and then,

I know this is a stupid question but if my motor did over heat and even though the gauge said the temp was good, What could have happend to the motor?

Any hints, clues, or guess's would be nice.

What should I look for?

Would there be a loss in power? Cause it feels like it still has all that it has had.

 

look for missing coolant. if you have no leaks on the ground but you are missing coolant it is being burned in combustion. you might get some white smoke but when mine were out it was not much at all, only at start up. also my temp gauge would spike very quickly out of no where and then go back down. it got worse and i added more coolant until i finally did the gaskets. good luck

 

im having the exact same problem... its seems that my gta would loose coolant after i just refilled the whole raditor with coolant... then my temp guage would all of a sudden jump to 260 then fall back down to normal.. i to experience bluish white smoke at start up and when the car idles... is this a head gasket problem... also recently when ive been starting my car up in the morning its been making this ticking sounds as if the lifters are hitting.. but my dad says that i have an exhuast leak around my cast iron manifolds......

 

88fastgta, I would look for a problem within the coolant system. It sounds to me like a radiator cap which may be frozen or a bad thermostat. -Bob

 

Just finished doing the head gaskets on mine.

My problems before hand were:

• Temp gauge would spike out of nowhere. Many times after exiting a highway onto a regular street.
• Losing coolant "somewhere." Not on the ground
• Oil and coolant were normal colours. No mixing detected.
• Coolant overflow tank bubbling while coolant temp was 180°F. This suggests combustion of the coolant, because water doesn't boil at 180.
• When the temp gauge would spike up high, I'd pull over and shut the car off. Feeling the radiator cap, it would be cold.

I had an emissions tailpipe probe put in the coolant overflow tank. It pulled 850 ppm of HC coming out of the coolant overflow.