Coolant/rad level question:

my qv was running hot to and was told to bleed the rad and I put more antifreeze in to about 1/2" from the top,the car runs much cooler now you don't want air in the system,so you need to bleed the system about once a week for awhile, here's what I did,at the rad. on the right side a brass round knob open it up just enough to hear air or some water coming out,start the car open the lid to the expasion tank,fill after the temp raises,thats when then the temastat is open and water is passing through the rad,when there's a steady stream of water coming from the brass knob,close it tight and put the lid back on the expasion tank,go for a drive,b4 you shut it off open the brass knob again to make sure theres no air in the line,do this for a couple weeks and I bet you'll see a difference in temp right away..............

 

I hope that is the problem but still bleed the system my car is running 30 degress cooler

 

That's too high. I'd take a gues at one of three things:

Your expansion tank cap is failing & has been chucking out coolant & your coolant level is actually low leading to localised overheating. Normally your tank would be pretty much dry but its possible for the tank to have coolant in it with a big airlock somewhere in the system. Bleed it from the Rad & the T'stat housing to find out.

Second option is there is a problem round the water pump & either your Water pump belt is slipping or the pump itself is failing.

Last option is that your gauge is lying to you. You could check the connections on the sender (in the middle of the V under the plenum). Bad gauges/senders are normally charcterised by either no reading or erratic readings though.

I suppose you could also have a bad/sticky thermostat or your rad could be blocked.

Unless you are really, really caning it the water temp should be static at around 175-180 whatever the weather. In traffic you'd expect it to climb to 190 (ie the middle mark on the gauge) at which point the fans should come on & drop the temp back to 175.

Suggest you figure out if the fans are coming on - just warm the car up & leave it to idle. If they do come on then look at what the gauge says when they do. If its at 190 then you know the gauge and thermoswitch are basically OK because that's the temp the things are supposed to cut in at. At that point you need to start looking for whats causing temps of 105. Also look for coolant being chucked out the overflow by the left rear wheel (that would indicate a failing cap)

If the fans cut in at higher then 190 then the gauge could be bad - but so could the thermo switch that controls the fans - more likely the gauge/sender in which case you may not actually have a problem at all (except for the gauge/sender of course).

Engines running hot blow gaskets & warp heads so suggest you get on top of this & figure out what's going on soonest. The 328 cooling system is good & not usually at all marginal (like the 308), even when running hard in my experience. The car should never run hot, even in traffic & if it does, something is not right.

I.

 

The coolant expands when it gets hot. That's why you leave the "air gap" in the resevoir tank so it can expand into this area (compressing the air) rather than get shot out of an overflow hose. So.... your level should be higher when the coolant is warm/hot because of expansion.

 

No doubt the lower coolant temperature you saw was due to proper bleeding. Adding a little more liquid above the recommended level is not going to make a noticeable difference and in any event, adding water would be better than adding antifreeze for these purposes. Antifreeze does not transfer heat as well as water. An engine running on only water will run cooler than one on antifreeze. We add antifreeze because, as the name suggests, it will keep the coolant from freezing down to a certain point, it has anti corrosion properties (when fresh) and lubricates the water pump. Probably some other properties that I've failed to mention.

all good stuff that Iain wrote too....

 

the antifreeze/coolant that I added was 50/50 which means 50% water too! also there is antifreeze/coolant out there that do transfer heat and cold,-24 dregrees to +275 dregrees,I would never put straight water thats crazy

 

I'm sure you know that antifreeze is also sold in undiluted form. You did not write in your thread "antifreeze/coolant."

Who said antifreeze does not transfer heat or cold?? Wasn't me. Of course it does. ALL things transfer heat and cold (some better than others). What I wrote was that pure water is better at conducting/transferring heat than pure antifreeze (or a 50/50 mix for that matter). It is also easier on a water pump to move pure water rather than pure antifreeze or a mix of the two. Less drag (power loss) although I'm sure the difference is minimal. Furthermore, I was not/am not suggesting that anyone use pure water in their cooling system.

FYI..... Some racers do not use antifreeze. "Red Line manufactures a cooling system additive called Water Wetter which is capable of reducing the coolant temperature of a high-performance vehicle by 15-30°F and can provide even greater reduction in cylinder head temperature which means greater volumetric efficiency and allows more spark advance. WaterWetter also provides rust and corrosion protection in plain water which can provide additional cooling efficiency compared to antifreeze."

http://www.bits-pieces.com/pages/whyredline.html

 

I guess I miss understood you,but right on somethings and your right I didn't say excatly what I was useing,I think I'm going to look into some of the red line products I've heard so much about the oil and fliuds out there that are good or better that the norm! have a good sunday where ever your at eulk328.............

 

I've often thought about using Water Wetter but never had an overheating problem so..... on my Saab I started using only one third antifreeze because the damn price has gone up so much (I believe it's a "petrochemical" which I was not aware of earlier). Of course I was going through quite a bit because I had a leak that took me forever to find.

A good weekend to you too Michael.

 

Supposedly the WSM specifies the proper coolant level should be 6cm below the filler neck sealing surface. So that would be 6cm below the inner lip of the filler neck that the cap seals to. In a properly running system, with a good cap, that should work. Sometimes, (esp with the older "2 ear" .9 bar cap) you have to keep the level a bit lower or it will spit or overflow a bit until it finds it's equilibrium.

 

The "jumper" trick is a good one, and also helpful if one of your fans dies, and you need to keep the last remaining one running continuously to get you home. I did this for a friend once on a trip. He kept the heater on full, and the car moving and made it home...but it was touch and go.