so the wife, kiddo, his friends and I went on a 40mile round trip (in our 2004 chevy blazer 4x4 automatic). 23 or so there 23 back. on the first 23 NO ISSUES coolant gauge stayed just below the 210 mark. we all hit the arcade for approximately 2 hours. on the drive back on the final 5 miles the gauge jumped all the way up to the 3/4 mark. we dropped the kiddos friends off and upon turning the car off of course we had the radiator boil into the overflow and spilled in the friends street D:< let it sit 10 min drove it the 200 yards home. checked the fan clutch, stopped spinning almost immediately. replaced the thermostat just last week. bled the system just last week (jacked up the passenger side even flushed the heater core due to a no heat issue and changed the coolant out) oh! and the coolant rises temp FAST when the A/C is on
so here's what I'm planning on doing.
- taking thermostat out and drilling a 1/8 hole into it or possibly larger i know thermostats are **** right out of the box and I don't want to risk repeatedly getting a **** t-stat
- replacing the radiator (assuming it will be gunked up like the heater core was)
do you all think these are some good proper steps?
what i know.
-dex cool does like to gunk up and clog radiators at the bottom
-no coolant in the oil or vice versa
-no coolant into exhaust
-radiator holds pressure
-i use 50/50 dex cool ONLY
-water pump is not seeping from seep hole

the wife and i have a romantic camping trip planned in 2 weeks so some nice help and some brain picking would help!!

 

I have had good luck with thermostats on 3 different vortecs, 2 blazers and 1 sonoma. I would go that way. But you cant go wrong with a new rad, especially if you've had flow problems. Maybe see about a good flush with new fluids before the trip. If you start seeing high temps, your water pump could be going(how old is it?).

if you haven't had any leaks in your rad or anything, maybe see about flushing first. Atleast that way if you need to replace anything, everything is already cleaned out.

 

go which way with the thermostat? (drilling it?) i did just replace it last week. and the water pump is a mystery, just got the car roughly 3 weeks ago and it showing some colors. the radiator fluid before the flush last week had some debris in it and i flushed her good, but i have heard of the fluid creating gunk at the bottom of it. i always thought that when the WP starts to go it will seep first? would it be a on and off kind of thing? I don't understand why it would get hot after cooling down on the same amount of travel home from the destination with no issues to the destination. minus turning the AC on 5 miles or so from temp spike time.

 

Sorry, I skipped over a new thermostat aparently. But when my water pump went or was going, it did not seep. I wouldnt drill the thermostat myself, but that's me. And if you had debree in the old fluid, then maybe take a little out to check it out again, could show more symptoms.

 

the symptoms I am experiencing after reading a few other posts is not leaning to WP. and idk I don't think i have air in the system but i am also not sure if it is pulling from the reservoir either. this is so odd to me. I let it idle in the driveway for literally a hour when i did the job and revved it and all and the temp didn't budge that day. but on the way home it went up, it seems pretty intermittent which leans me away from water pump? if it was made in 04 and the radiator has never been taken care of doesn't the dex cool over time get really nasty?
*it did pull from the overflow, will be attempting another bleed. and checking temps of hoses for flow

 

something i found slightly odd, after doing the bleed and run for 30 min or something around there. i replaced the cap and let run a little longer. after turning the vehicle off and watching the fan i figured i would squeezer a hoser. and when i did, i heard fluid going into the overflow. shouldn't the hoses be firm???

 

That is not my expertise, but I'm thinking that might be a good thing, shooting it into the over flow means you over pressurized the system, there for letting some out into the overflow. I would check the level and see if it goes down, or if you notice anything.

 

well, what i found out was the system was not pressurizing. so i ran down to the autoparts store and purchased me a stant pressure release cap. system now pressurizes, with ac and idle for a long time and a 10 min drive there and back at idle with a/c on idles at a notch above the 210 (could be a faulty gauge) and without a/c idles at 210 on the notch. hoses have pressure in them now. may have solved the issue?! *shrug* will test drive to find out for sure. without a thermo gun there is no absolute if i know the gauge is reading high or not but thats pretty common with these fantastic vehicles

 

Well I'll bite my tongue next time lol...

 

by all means do not! thank you for your help don! always helps to toss ideas back and forth!! again thank you