Oh goodness, I done did it this time.

[cal_look_zero]

Well after a solid 22k miles of thrashing my franky equipped OBS, I think she let a head gasket go today. Got to the freeway offramp and the gauge started to spike. Drops back down when I'm driving, comes back up on idle. Got to work and my overflow was starting to boil. Had some overheating last week and changed out my thermostat for an OEM one, but I think it may have been too little, too late. Bollocks. Here I was hoping I wouldn't be commuting on my CBR this summer.

Dammit Jim, I'm a doctor, not a mechanic!

[idosubaru]

overheating at idle and temps dropping while driving is usually not headgaskets, it's usually:
1. low coolant (a leak somewhere)

2. fans not coming on properly

 

coolant overflow will boil on any car when they simply get too hot, it's not always the "exhaust pushing into coolant" like the old fashioned internal EJ25 headgasket failure.

 

it is of course not a fun sign...but let's hope you've got some luck?

Edited May 8, 2013 by grossgary

[cal_look_zero]

overheating at idle and temps dropping while driving is usually not headgaskets, it's usually:

1. low coolant (a leak somewhere)

2. fans not coming on properly

 

coolant overflow will boil on any car when they simply get too hot, it's not always the "exhaust pushing into coolant" like the old fashioned internal EJ25 headgasket failure.

 

it is of course not a fun sign...but let's hope you've got some luck?

 Come to think of it, I have heard some dribbling sounds in my heater core on startup. Well I'll do a flush and refill in the morning and report back. I've got 2 other cars and a moto to use if need be.

[95legwagon]

maybe the coolant system needs to be "burped"?

[Rooster2]

 Come to think of it, I have heard some dribbling sounds in my heater core on startup. Well I'll do a flush and refill in the morning and report back. I've got 2 other cars and a moto to use if need be.

before a flush, look first to see if your radiator is low on coolant. If so, top off with just pure water, and look for a leak at a bad rad hose or radiator itself. You might get lucky and find the leak. If so, fix the leak, then do the flush and add new coolant to fix the problem.

[davebugs]

maybe the coolant system needs to be "burped"?

I ALWAYS remove lower rad/WP hose and refill thru top hose when any doubt abotu air in the system.

 

Toping off doesn't solve the heater core or other air bubble issues IMO.

[Fairtax4me]

Sounds like low coolant from this side of the interwebz.

Heater core gurgle (that trickling water noise) is usually indicative of low coolant.

Look for leaks. The thermostat housings like to weep a little.

Radiator cap could be bad as well.