Could use some advice on this overheating, its not making sense to me...

my temp gauge was swinging from 1/4 to 3/4 over a 30 second period a few weeks back, I first noticed it after I had my oil changed at the local Valvoline drive-in, and then one day I noticed the check gauges LED popped on; it went over into the red line. I was only a couple miles from home so I drove it straight back without stopping (i know, i was cringing all the way) and as I was near home, the car started bucking like mad, ready to stall, had to floor it to keep it running.

The odd thing is after about 10 seconds of bucking, the engine popped back to normal and I saw the temp gauge drop to a tad less than 1/4. It stayed low the rest of the way home.

That got me thinking it was a sticky thermostat so I replaced it (note: the fluid was a reddish-pink color?). Refilled radiator and overflow. Ran great at a solid 1/4 for 2-3 weeks.

Now its back, swinging up to about 3/4 and then back to 1/4. It hasn't tipped over the redline yet at least. I guess it wasnt (all) the thermostat? Still has fluid in the radiator when I popped off the cap. I'm thinking the next step would be a flush for crap floating around in there but I'm open to other ideas.

Oh and I get the occasional whiff of hot coolant smell, rarely though. I can't see anything dripping but its pretty hard to see the radiator surface at all. I searched the forums and didnt find anything relevant in the first couple pages of results so I figured I'd throw it out there.

97 Camaro with a 3.8L, nothing custom, 160k miles... any ideas?

-Dirk

 

Flush it out for an hour or so, then 50/50 anti freeze to water. Let us know how that works out.

 

Sounds like the system needs to be purged. The T-stat housing is higher than the radiator on the 3.8L so air gets trapped in there and keeps water from flowing. That is what that little screw looking thing at the top of the water outlet is for. The reddish pink color coolant is Death... I mean Dex Cool. I am not a fan of the stuff but if all is well in the cooling system it works good. If you put green AF in the car I hope it was the "all makes all models" type or you may have some mud issues. Mixing standard "green" AF with Dex Cool will create a brown jelly like stuff that is poor for cooling. Flush if you did.

The last thing that could be the issue with the engine is the 2 plastic elbows that are located on the heater hose manifold. One goes into the water pump and the other into the intake manifold. These can let coolant out and also let air in either of which can cause over heating.

Massey

 

Thanks guys, that's kinda what I thought, glad to hear it didn't sound like something worse. I didn't mix colors, I had heard that was really bad, so no mud

I didn't check that junction tho, good tip there.

Again, thanks much!

-Dirk

 

Let us know if that helps your over heating problem.

 

well, good news... it was my fault it was overheating but it was a quick fix.

After replacing the thermostat a few weeks back, I didn't bleed the air out enough, or just missed some... had a ton of it in there when I went to flush it. Cracked the screw, added some more fluid, and 10 minutes later it was running like a dream.

And here it thought the thermostat was an easy fix!

Thanks again for all the suggestions

-Dirk