elzergone

OK. I must be the worst at bleeding the coolant. Either that, or there is something bigger going wrong.

I've been attempting to get the coolant properly bled over the last few days, and I just cant get it right. It runs below the first line during normal driving, even when driving more spirited, it still doesnt raise much above that first line.

HOWEVER,

My daily commute involves a several mile long fairly steep uphill section. Today, it was doing fine for most of the way, then it started rising, and then suddenly jumped up almost to the red. I checked the heater and it was blowing cold air, which says to me there is air in the coolant. Then the warning light came on, and I pulled over immediately and shut the car off.

Popped the hood, the engine smelled very hot, the upper radiator hose was rock hard, and the fans were on full blast. Without thinking, and being kind of upset, I opened the radiator cap, and naturally it blew off and a bunch of coolant gurgled out. Stupid me.

So, since I've been carrying around jugs of distilled water during this constant bleeding adventure, I filled up the expansion tank, started the car, and drove it back down the hill. The temps almost instantly dropped back down to below the first line, with only the occasional jump up and down the rest of the drive home.

I felt the upper rad hose when I got home, and it wasn't rock hard, just normal. So I took my wifes car to work, and now I'm sitting here wondering how much trouble I'm in. Headgasket? I hope not, I just did that along with the head rebuild. Clogged radiator? Or do I just really suck at bleeding the coolant??

krystar

wow u should really heed the warning "do not open while hot" you can get burned really bad with superheated water.

have u noticed loosing coolant? i think it just wasn't bled fully.

elzergone

Oh trust me, I'm well aware of how dumb it was. I think my brain was just turned off at the time.

elzergone

Oh sorry krystar, I missed your question. It doesnt seem to be losing coolant. Just venting when I fill it up too much.

Ok, I pretty much follow the bleed advice on clarks garage, with the addition of blowing into the overflow hose with my hand over the expansion tank opening. Is that still the recommended way?

smokin_944

Which car? The 84 or the 86? The cooling systems are different.

cruise98

The cooling systems on these cars are a pain to bleed.

When you fill and bleed the coolant, be sure the heater is set to hot so that the heater core is filled with fluid. After it has idled for a while with the bleed screw open, blip the throttle and watch what comes out of the bleed screw. When the air bubbles are gone, it should be nothing but coolant.

It may help a little if the front of the car is higher than the back.

elzergone

The 86, shoulda specified.

I bled it AGAIN last night, and drive it around. It seemed fine, even when driving hard. So, as a test, I drove halfway up the hill I take to work... and it overheated in the exact same part of the road

The coincidence is almost insulting. Temps shot up, oil pressure dropped way down. Pulled the car over and shut it off. Upper rad hose was hard as a rock again. Opened the bleed screw and a bunch of steam came out. Started it up and drove down the hill. Temps nearly instantly dropped back below the first line, with just a few fluctuations.

I'm thinking it must be air, because it only happens while going up a steep hill. I can drive it at 5k rpms in third for as long as I want on flat ground and it does fine.

I'm so close to ordering a vacuum filler system, because this is maddening.


I do make sure the **** is turned all the way to hot. Whats funny is that when I idle with with the bleed screw open, water never comes out in any significant amount. A little dribble if I rev it, but never a steady stream.

Could my water pump be bad?

PeteL

You still have an air bubble somewhere in the coolant system.
One other thing to try is to lightly pressurize the system. Fill the system. Open the bleed bolt, pinch off the overflow hose on the coolant tank, and perform mouth to mouth on the opening in tank. (clean it good before doing so)....coolant should come out of the bleed bolt.

StoogeMoe

This sounds like a problem another dude had just a week or so ago. It kept getting air into the system and wouldn't circulate the water. His problem turned out to be a small leak which was letting in the air. Pressure test your coolant system to determine if you have a leak.

odurandina

could be air could be the H2O pump but, the fan (relay ?) switches were a problem on these cars no ?

cruise98

Sounds like air in the system to me. I have a vacuum filler and the system still has to be purged of air after using it.

944Ross

Drive it to that big hill (with the cap off if you can), park on the steepest part with the engine idling, and open the bleed screw. Fill the reservoir until water comes out of the bleeder. I have to park on the steep part of my driveway (idling, cap off, bring it up to temp idling) to get it bled, but once I do that, no issues.

elzergone

OK, latest update.

Thanks everyone for your posts. I think I'm getting closer.


So, today I jacked up the car, changed the oil and filter, since it was time anyways. Then I bled it again. The front of the car was as high as I could get it on jack stands. I took off the expansion tank cap, opened the bleed screw and started it. I let it run for about 15 minutes or so. The heater was on full. After a while, water started steadily dribbling out of the bleed screw. Let that go for another 5 min. or so. Then closed the bleed screw, put the cap back on and lowered the car. The coolant is currently over filled, so it vents when the car is shut off.

I took the car for a drive. Driving normally on flat roads and highways it stays either at or just below the first line. Then I took it up the pass I would normally take it work. It did do better, thats for sure. The needle slowly rose higher, getting up to the last white line, but never going above. At the top of the hill, I pulled over on flat ground and let it idle. This was after about 8 miles of fairly steep uphill. Elevation gain of about 3000 ft. At idle, it SLOWLY went back down to about midway, oil pressure was at about 2bar. Driving back down of course it was reading cold, since I was just coasting in gear the whole way. Back on flat ground though, it rose back up and stayed at about the halfway point most of the way home.

No red lights atleast. Does this sound normal? I'm at a loss I guess. It used to be that the coolant gauge almost always stayed at below the first line, only getting above the halfway point rarely. What is normal?

I suppose the next thing I'm gonna do is pressure test it to see if there are any leaks or places where it might be drawing in air. After that... taking the radiator out and flushing it.

This is getting silly.

Thanks everyone for any ideas

J Berk

I recently had an overheating problem that turned out to relate to the fact that the PO had apparently replaced the waterpump with the $40.00 variety with the plastic impeller.

The impeller's vanes were almost completely gone....it would move enough water to idle cool but at 60mph for any lenght of time it would overheat.

Interestingly enough...at 80mph it would run cool enough to drive and that is how I made it home!

Note that while overheating it would blow cool air from the dash because no water was circulating.

944Ross

Sounds like you've got the air out! But as far as going to the last white line on the hill, what temperature was it outdoors when this happened? Were you really flogging it?