I just flushed my cooling system on my '79 210 (1.4L engine) and when I pulled the thermostat I noticed it was jammed open - which explains why my car was running very cold on cold mornings by the way. So I went and bought a new one, put it in and went to fill the radiatior back up. I was only able to put in about half of what's required (about 1 gallon) before it was full. So I ran the engine for awhile, drove it around a little and when I got back I saw that it was still full. So I'm wondering - when will the level drop so I can fill it all the way? Does this mean my valve isn't opening to let the coolant into the block? Also where is the temp sensor supposed to be on this engine? I've noticed that the temp goes UP after I turn off the car for awhile. There's an aftermarket gauge so there may be an aftermarket temp sensor in the wrong place somewhere. If I knew where the stock one is supposed to be I can disconnect it to see if that's the one the gauge is using. It reads about 180F at normal temp (is this too high?) Also I'm worried that the temp sensor could be in the wrong place ie reading the radiatior temp instead of the engine temp or something like that. That could be trouble.

Oh I just thought of one more thing. I flushed the system by disconnecting the water line on the back of the engine that goes to the heater core and flushed wather through that way. Could that have left water in the block, which is why I can't fill it all the way? If so, then my water/coolant ratio is off. I guess I should have drained the block after flushing (though the manual didn't mention that!!!) That means I have to pretty much start over.

Oh one more thing - where the hell are the block drain plug(s)? The manual says on the "left side of the block" whatever that means - no pictures anywhere. Not sure what to look for.

Sorry for all the ?'s but thanks for the help anyway.
Michael

Hey there. While I'm no cooling expert-here's my two-cents-worth.
First, make sure your belt is tight. Easy. Although it may soon be shot down, what I do is drill a very small hole in the body of the thermostat and orient the hole towards the top. I found this helpful in letting all the air out of the system as it's being filled with coolant. It's always worked for me-kind of a poor man's wiggle valve you see in expensive thermostats.
Make sure you've got your heater control fully over to the warm side-it opens the valve to the heater core and allows the coolant to circulate.
As far as the temperature going up with the engine off, that's normal on all engines. With the fan not turning, water pump not pumping, and no air rushing past the radiator, the engine will "heat soak". It will probably raise in temperature by 10-20 degrees before it starts cooling down. An electric fan with a thermostatic control helps with this. They won't shut off until the preset control reaches the highest setting.
180 doesn't sound too hot to me-really depends on climate. If you're in a hot climate it's probably normal to see that kind of temperature.
Hope this long-winded post helps!
-Donnie

Oh hey- the block drain is below the intake and exhaust manifolds, about the middle of the block. There's lots of pics of engines out of the car on the site-may give a good visual.
-Donnie

Hi Donnie,
Thanks for your help. The thermostat I bought has a little hole built into it for that purpose I guess. After driving it several times I'm convinced that it's full due to the fact that I didn't drain the block after flushing it. I think I'll remove some of the coolant and add antifreeze without water to get the mixture ratio back. Oh and thanks for the info on the drain plug. I'll use it next time! At some point I'll go through my manuals to find where the temp sensor is. It's got to at least be in the FSM.
Michael

The temp sensor in your a12 is beside the thermostat housing, right on the cylinder head,sticks out the right hand side, with one yellow wire on it. I'm pretty sure it's yellow anyway.
-Donnie

Quote:It's perfect -- assuming you bought a 180 degree thermostat. They are available in 160, 180, 195, etc temperatures. 180 is probably the best for a street car, as oil is designed to work best at this temp. 160 is better for hp (assuming you retune the carb jets, etc), while 195 requires a high-pressure cap which might cause the cooling system to leak.

Thanks guys. By the way, I drove it in to work this morning and it runs much better now that the thermostat is closing when it's cold. A couple of weeks ago it didn't even get above 160 for most of the way to work which probably isn't good for the engine. I wonder if my milage will go up at all now that it's running at the right temp all the time? I guess I'll find out in a couple of weeks. At this point I'm getting about 28-29mpg with about 30% highway driving. I'd like to get over 30mpg at some point. Damn I wish I had a 5-speed!!!!
michael

Update:

Maybe I shoudl have left the thermostat alone. I have a feeling it was stuck open on purpose so the car would run extremely cool. Since replacing the tstat the car overheated pretty bad and now isn't holding coolant. Took it to a shop and they said the coolant is heavily contaminated with hydrocarbons meaning the cooling system is leaking into one of the combustion chambers, meaning blown head gasket or cracked head I suppose. I'm guess the previous owner knew about this which is why the tstat was stuck open. Damnit!!! SO it's time to pull the head and figure out what the probem really is. I sure hope it's jsut the gasket!!

So by the way, anyone know of a good electric fan swap and/or radiator upgrade? I never want to have an overheating problem again once this is fixed. Being in TX it doesn't take much to overheat. Thanks,
Michael

Quote:Many hours/cooling cycles. My experience is that it's usually the next day, after two trips. I once drove 125 miles before the level dropped and the temp spiked. So we pulled over, let it cool off then topped it off.

Quote:The right and left sides of the car as always relative to how you sit in the car. Sit in the drivers seats. The left-hand side of the engine will be on your left hand. The block drain plug is below the intake manifold, seemingly high up on the block.

Quote:Actually it means just the opposite -- combustion products are leaking into the cooling system. Yes, head gasket problem.

Just remove the head, scrap both surfaces absolutely clean, double-check the head for flatness (they almost never require milling) and put a new gasket back on. See Changing Head Gasket.

Quote:It will be easier to tell when the engine is still together. Do a compression check, but more importantly a cooling system pressure test. While the cooling system is pumped up to 14 lbs, listen for the leak and pinpoint its location. Put a hose to your ear and move the other end into the valve cover, into the intake and exhaust. Also check out the intake manifold cooling passages i.e. coolant goes through the intake gasket (and so does hydrocarbons).

Quote:The most reliable system by far is the stock fan. If it fails, the charge lamp on the dash lights. If you don't have the fan shroud, get one off the wreckers. This system cools better than most electric fans.

Quote:Sorry to say this is a pipe dream. The best advice may be: don't let the coolant level drop ... and keep your eye on the temp gauge just as you frequently check the rear-view mirro. if the temperature rises unexpectedly, pull over before it overheats (boils over).