My turbo accord is my daily driver and I just recently moved - I now drive ~20 miles each way to/from work daily.

When driving to/from work I'm having coolant issues - specifically coolant coming out of the overflow.

It does NOT happen on short drives, even when boosting hard around town, only when driving a long distance. I hadn't seen this happen much at all before I moved (a couple of times when driving long distances) but now with the commute it's become almost a regular occurance.

I've pulled the logs and strangely the coolant temps are pretty stable under boost, but once I let off the gas the temps seem to go up. No knock logged at all.

I'm thinking that my cooling system just may not be able to stand up to long drives.

cooling: stock radiator, 1.3 bar cap, silicone hoses, water pump < 1yr old.

head is held on with ARP studs, torqued to spec, and re-torqued after the initial 1000 miles. OEM hg w/ copper spray.

No coolant in oil, no oil in coolant. (at least visibly)

Will be doing a compression test this weekend, just looking for opinions. Thanks.

 

does your coolant fan work?

 

yes, the fans are both running at all times.

 

signs of a bad HG

pull all 4 spark plugs and look into the cyclinders
check to make sure all the piston faces look the same, with carbon build up
if one piston face looks cleaner then the others then you might have a bad HG

check the over flow and see if its clean or if its got dirty crap in it

remove the rad from and idle the car, do you see any bubbles or foam forming?