Coolant temperature fluctuates
 

hey RS,

I need some advice about the coolant temp fluctuating on the car. It's a WK2 5.7L V8 hemi. The thing is... i think the optimal temp that it should be when the engine is warm is at the 3/8's of the gauge. From time to time, especially during stop and go traffic, it tends to climb up to 3/4 of the gauge then the rad fan goes on full blast (really LOUD) and cools it back down. (that was the worse I've seen it do)

I've tried to "burp" it twice.. it helped a little bit i suppose but it still happens.

Do i have a bigger problem or should i just keep burping it? There's no CEL. Is it the thermostat or radiator failing?

Any help is appreciated.. Thanks

-Burn

If you're sure it's bled, then you have another issue.

Possibly, fan switch(or thermo-coupler), thermostat, rad, head gasket, etc.

First, check if you're coolant level is dropping.

Ok thanks. I'll keep an eye on the reservoir.

How old is your hemi? Do you do the servicing yourself? If so, it sounds like a stuck thermostat.. or a dying water pump.. If you get your servicing done at a shop.. just make sure you have BCAA and get it towed there when it fails?

if you dont drive it for a few days + its dry, look for streaks of white on the inside of engine bay.

Older GC's used plastic/metal combo for radiator that cracks where plastic meets the aluminum. Pretty common issue on the older ones especially in colder months where metal shrinks faster than plastic, causing plastic to crack. No idea if they kept the same construction for WK II but i imagine they did

Thanks guys for the quick input. It's an '11 with 120k kms. unfortunately, i drive the car almost everyday so I'll have to wait but I'll check for any cracks nonetheless.