hey guys

Ive noticed that lately when ive been driving my temp gauge has been dropping from its usual position. it never goes above halfway but ive noticed that when driving the temp gauge will go up to its normal halfway (albeit takes longer to reach halfway than it used to) and then it often drops to quarter, then back up to half again and so on. this never used to happen until i changed my coolant.. now i have a hairline crack in the radiator so it could be that? im not sure, any ideas? i hear that it can be real bad if the temp gauge starts dropping.

hairline crack in the rad doesnt sound too healthy! When you changed coolant, was it diluted to the correct temp or was it a pre mix?

you have a bad thermostat and you need to get a new radiator. Change them both at the same time

ya the crack would cause it to go up not down...i had the same prob(rad) well mine spiked one day and i replaced it and its been running like a champ but since you have thermostat and crack in rad go ahead and do both otherwise your temp gauge will nvr read right

yeh lol i tried to patch it but theres too much pressure in the radiator to keep it sealed. i thought it could be the thermostat. ill get on to those right away, thanks 4 the help guys

spend the money now that you know you can budget for. Rad and t-stat asap until more things crap out.

Replace the radiator, because thats a huge headache waiting to explode. However that has nothing to do with your issue.
I had the same problem. I replaced the thermostat, but it didn't fix anything. Then I changed out the coolant temp sensor for the gauge, and the problem was fixed. Just make sure you get the right sensor, because there are two.