Overheating...AGAIN! Back to the drawing board...
 

Well...I'm back! Same problem as before. I guess my 96 went dormant for a while and then erupted/woke up again. About a year-ish or so ago, driving my 96, everything aok, then BAM, I'm boiling over out of the overflow tank. At that point I checked the Meziere electric water pump, it had 12v running to it and you could hear running. Everything pointed to the thermostat. Took it off, put a new one on. Just for the heck of it, I wanted to see of the old one worked. I put it in a pot and put it on the stove. When the temp climbed, it started to open as it should. That being said, people were still telling me, "that doesnt mean it wasnt the problem...could be getting stuck at times...". So nonetheless, put everything back together and took it for a spin. Drove fine, no overheating, etc. Ive driven it 6-7 times since(which is a lot for me) and probably put 100 miles on it. Everything seems ok...

Today, not having driven it in a few months...I thought, "wth, I'll drive it to my dr's appointment(bout 15 miles away)". Nice and crisp/cool 35 degrees outside here. Started up, all is good, going down the road and then my dash lights up like a christmas tree. Yep, Im at 258 degrees and climbing...262, 265...I shut it off. Smoke pouring out from under the hood and antifreeze boiling over out of overflow tank and all on the ground...lovely! Luckily I was pulling in the dr's office parking lot. I was in there roughly an hour and a half. Come back out, 147 degrees. Try to make a mad dash home. I make it about half way and we're back to 255 degrees. Shut it off and pull over for a half hour. Start it back up and I'm at 203. Make it about 3 miles and back at 260. This thing is climbing like crazy! While driving this 2.5 miles, just for the heck of it, I turn the heat on full blast and see if it bring the temp down. Air starts out cold and then 5-6 seconds later, its piping hot. It actually pulls the temp down from 245 to 215 and then shoots back up again while the air starts to turn cold. I coast into the grocery store near my house and shut it off again. I turn the car off and you can hear it boiling over. I turn the ignition on and put the heat on full blast to see what happens. It drops from 260 to 217 in roughly 15 seconds and stops boiling. Now Im scratching my head...? Wait about 15 mins and make a last mad dash home. In less than a mile, it jumped from 209 to 238 as I pull into the garage and shut it off. Turn the ignition on and put the heat on full blast again, doesnt go down a bit and of course, bubbling and boiling over out of the overflow tank.

WTF?!?!?!?!?!?!?!?!?!?!?!?!?!?!?!?!?!?!? !?!?!?!?!?!?!?!?!?!?!?!?!?!?!?!?!?!?!?

It works today, but not tomorrow or on Saturdays but if is a Wednesday night or Friday between 1:17p-2:54p, then it works. But then again if its a Sunday anytime other than midnight to midnight, it wont work then either...grrrrr:willy:

The car has power and is not spitting or sputtering...just freaking overheating! Theres no trash or debris stuck on the front of the radiator. Radiator is a aluminum Be Cool radiator that has been on there roughly 4 years or so. What gives?!? Air in the coolant system? Bad water pump(everyone runs these Meziere pumps)? Another thermostat? Blockage in coolant system? :banghead:

Sounds like your electric water pump is on the way out! Happened to me...with no circulation your temperatures will go straight through the roof very quickly...not good for your head gaskets either because the aluminum heads expand at a different rate than the cast iron block.

Yea, no kidding on the heads...and Im running the AFR Super Comps which scares me. Is there a way to test the water pump to ensure it is working at full strength? I mean obviously you can see if its got 12v and hear it running but actually determining if its operating correctly...?

Symptoms of a ruptured head gasket allowing exhaust gases into the coolant.

A simple chemical test will confirm the presence of exhaust gases in the coolant.

How would I test that?

Most auto stores have the kit. Google 'exhaust gases in coolant', and you will find a thousand results.

A blown head gasket wouldnt make the car overheat intermittently though would it? Just saying since it did this last time and went away for 6-8 months and now it does it again. Last time I blew one, I knew it was blown and there was coolant in the oil. Not to mention it ran like completely crap until it was fixed.

No, a blown head gasket would not cause intermittent over-heating. It would be constant.

When was the last time the coolant was flushed, including removal of the knock sensors?

You definitely have a circulation problem.

1) Are you SURE that there is no debris BETWEEN the radiator and condenser., not just in the front of the condenser?

2) The "heat on, cool down" tells me that your fluid is not fluiding properly or enough. The fact that the heat climbs quickly says that one of your coolant hoses probably has a blockage.

3) Air is system? could be. Again Air and blockage will crease similar problems and have similar symptoms.

So, if it were me...

Full on flush the whole system. I'd remove hoses in sections and check the flow through. If something is partially blocked, you will see that fast. I'd also check the electric pump; it may be spinning but is it spinning enough? Also, check the block for a flush and pull the knock sensors.

I think you have a flow issue some where

Need an ammeter in line to the water pump.
Draw goes down, pumps not running.

If pump wasnot running it would not pump heated coolant into heater. You better check head gaskets before you do serious engine damage. If that is OK then pursue other faults. Im betting head gasket, hope not but check it.


https://cimg9.ibsrv.net/gimg/www.cor...8b52793ebb.jpg

If it's boiling out the overflow you're getting some circulation. Now you said the air turned cold out the vent after a while. Did you change that or did it happen on its own? If it happened on its own get a new water pump in there... Actually if it didn't come down the last time with key on and blower on I'd definitely replace the water pump.

Not necessarily. Boiling out the over-flow could be caused by exhaust gases in the coolant pressurizing the system.

Also true, you should get some burning through the exhaust too correct? Easiest way to check is that test kit or a compression test would also show it if it's that bad right?
I would tend to lean toward pump but 260 is pretty hot.if air was getting into the core from a leaking head gasket... It's really hard to say.

You are low on coolant. You are low on coolant. When the heat comes and goes....you are low on coolant. Top off your coolant, re test. If it start the same symptoms...check for a blown head gasket using the aforementioned exhaust gas test.

:yesnod: