1995 LT1 T/A, no real mod's.

The car will get super hot if I dont purge the system every time I start it. I have replaced the thermo (from napa, correct for lt1, 180*), replaced radiator cap (from GM), had the core of the radiator cleaned (took off the end caps and used a steel thing to clean it, new coolant (50/50 with dexcool), replaced the alternator, and have fans running full time.

you would think after all that, you'd have gotten the problem solved. NOPE, even after I purge the system (which the top port always has air in it), the car will still end up running hot if you idle long enough. and to top it all off, tonight the a/c wouldnt get cold.

Someone either help me or shoot me, I really dont care which

-James

 

This may seem very obvious, but you have bled the system from both bleeders, right?

 

yes, the one thing i didnt mention, i bleed both bleeders. the top one seems to be the big problem though. you would think after 3 weeks of purging regularly there couldnt be any air left in there. i am thinking its a leak somewhere (no signs whatsover to work with, no moisture in the exhaust, no smoke, no leaking on the ground, no leaking anywhere up top, and it doesnt really use water (although purging it all the time does, so I cant say that for 100% sure). So does it sound reasonable that a leak somewhere could be letting air in, but not letting water out?

 

by the way, i have devolped a high rpm stumble (may be totally unrelated), and since i did my plugs it sounds like a have a small exhaust leak (possibly a loose plug, maybe the reason for the stumble ).

just thought i'd share that, incase it rings some bells in peoples heads.

 

WP+Opti much?

 

is that really what it sounds like. i could see the opti for the stumbling, but air being introduced is a product of the waterpump. i guess if the water pump wasnt doing its job and allowed the coolant to boil, that would put air in the system.

 

If you havent already, go over all of your hoses and make sure they are tight. Just because water isnt coming out doesnt mean air isnt getting in. I had a similar problem with the top hose on the passenger side of the waterpump. I didnt have the clamp on tight enough and air was entering the system there although I had no leaks. I tightened it down and it fixed the problem. As for the miss, the opti could very well be the problem but make sure that all of your plugs are tight and your plug wires are tightly connected on both ends and in good shape with no burns or cuts. If youre good there, the opti might be on its way out.

 

A lot of times the WP will leak from the weep hole, drain onto the opti, and the coolant will boil off/evaporate before it ever gets to the ground. Just an idea, it happened to me. Driveshaft bearing was seized, pump was dead. Went electric, and will never go back.

 

HaVe the same problem, can't find any leaks, new water pump year ago. Temp and fans all ok, but if I do not purge every other day, get low coolant light, and coolant is low in radiator. When I do open the cap, you can hear the coolant run back into the bucket.
Was going to check and see where leak was (has to be an air leak) will keep you guy informed.
Love the forum, Frank
1995 z28 convertable, with hiteq direct ign.

 

Check the coolant in the radiator when cold. Make sure it is to the top and the reservoir has the correct level. If you have no leaks and are constantly purging air or losing coolant, it could very well be a head gasket problem.

 

High end stumble? have to bleed cooling all the time? blown head gasket or cracked head/block. what does the oil look like? and if you have a cracked head or partially blown head gasket on the exhaust side you will not see coolant in the oil as it passes out the exhaust, do you see puffs of white smoke out the exhaust when you get the high end miss?

 

I was thinking head gasket as I read this also. If all other places check out ok then its time to start looking deeper.

 

I had this similar problem and after letting it sit for a while (a month), i ended up with a a rod through the block when it started up. come to find out the #8 cylinder was full of antifreeze and when that cylinder compressed, it bend the rod like a twizzler then snapped it............good luck though

 

Get your coolant system pressure tested to see if it's leaking.

 

You guys are great. Thanks for all the help.
You forgot to metion, the exhaust smells funny , using coolant every day.
My next move it the pressure test, but I am pretty sure got a blown head gasket. Once when it sat for a week, when I started it, it sounded like a stuck lifter, then went away. It still runs real good, does not overheat, but it is not the same, heats up fast, once fans come on cools right down. Can not see any coolant on cement floor of garage after sitting for a couple of days.
Just wanted to let others know what I have observered. I will reply again after the pressure test.
Thanks again guys for all the help.
Frank
1995 Camaro conv LT1