Cooling issue, but this time it's to cold...

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Cudafever said:
The fact that you see water flow to the top of the rad at a temp on the meat thermo that is well below the proper t'stat temps says that the t'stat is somehow opening.... or there is some way that the coolant is bypassing the t'stat. Are the t'stats sitting very snugly in the recess in the housing? Have you looked at both the manifold AND the t'stat housing to be sure that there are not recesses in both that can allow flow around the outer edges of the t'stat?

nm9stheham, i think you're on the right track there.

It's not the heater core.

Do you have a stock radiator?
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I considered that too, but figured the t/stat would just keep closing till closed to compensate.. If it's bypassing somehow, why did it open?

But I certainly would be looking at the t/stat mounting as well..
 
nm9stheham said:
I'd pull them all just in case there is something different front to back.

I caught the check on the temp gauge so feel your gauge is not lying to you. I just have to wonder if your t'stats are being pushed open by the pump pressure; this is something that you cannot test on a stove. They DO have to have a certain spring pressure to keep close in the presence of the water pump's pressure. Only replacing with a good one will determine that. (I can't tell you how to test the spring pressure.)

The fact that you see water flow to the top of the rad at a temp on the meat thermo that is well below the proper t'stat temps says that the t'stat is somehow opening.... or there is some way that the coolant is bypassing the t'stat. Are the t'stats sitting very snugly in the recess in the housing? Have you looked at both the manifold AND the t'stat housing to be sure that there are not recesses in both that can allow flow around the outer edges of the t'stat?

What brands are the t'stats please?

Any thing odd in the head gaskets? Is this a Magnum 360? Just wondering if the head gaskets could have gotten flipped front to back and the coolant is not following the right flow pattern.
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Stock radiator, not a Magnum motor. I believe there is a recess in both sides, the tstat housing and the intake side from memory. I'm going to have to open that back up and look, what should I get to fix that? it's an Edelbrock Performer intake and I don't know where the neck came from, I'll bet water is going right by it. I can see the gauge fluctuate at different speeds, not flutter but move up or down with the airspeed on the radiator, it shouldn't do that with a proper functioning tstat. I didn't pay attention to the brand of tstat.
 
OK on the non-Magnum.... if the head gaskets were flipped end to end then the rockers would have oiling problems. As I recall and from the Edlebrock pix, there should not be a recess in the manifold but it's sure worth checking. We have the same manifold with a stock type t'stat housing and the t'stat works fine.

It pretty much seems like the t'stat is being pushed open by pump pressure alone, possibly as the element heats up a tiny bit. Time for a Stant, please. There HAVE been reports on this site in the past of multiple bad t'stats...... and the big box store stuff is always suspect.

And the temp will go up and down some with airflow and engine load changes with a properly operating t'sat; the t'stat HAS to have coolant temperature changes to change its opening and do its job. It should be in fairly narrow range with normal cruising around, but it will be there.
 
I think the gasket covers up the outside edge of the t stat but check it out when you pull it apart. You could cover part of the radiator, say half or so on a cooler day, take for a test drive watching your temps, if it brings up the temp your t stat is not doing it's job. Just keep close eye on the temp and be able to pull over and remove whatever you used to cover the radiator. Cardboard works well.
 
Before I pull it open again I'll get the Stant on hand and test it, I'll see what happens with the recesses and put the new Stant in. I'll report back on the findings. Thanks.
 
I seem to recall an overheating post where the coolant was moving too fast through the rad to actually cool the coolant due to an oversized or many blade water pump.
Could too much pump pressure cause the stat spring to stay open? Just something to possibly consider.
 
The pump is new, I went with a standard flow. I'm going to upgrade to an aluminum radiator soon but till this is solved I don't need it to run any cooler LOL.
 
If the gauges are on a T or extension of ANY kind you can get a low reading on temp.
You will get gauge reading 10-15 degrees below the actual coolant temp.

Just an FYI incase your gauges are.
 
Have some other things going on but, as I warmed the engine tonight for another issue I watched closely to the temps and had the radiator cap off to moniter. The engine warms pretty quickly, normal few minutes, very slow flow in the radiator from the bypass. As the gauge climbed to 170 ( keep in mind this is no driving, just sitting ) the water started to flow in the radiator. The temp after about fifteen minutes went to 190 and never got any hotter than that. The heater in the car had plenty of heat long before the stat opened. So from the start of this I was asking for help with why it cools to much while driving with airflow. All systems are operational and working correctly parked, but I can drive it all day and the gauge will barely if at all get to 120, and only if I get on it a little it will go to 150 but only till I start mild cruising, then cools right back down quick, if I just baby it around the gauge barely moves?????
 
The bypass does not allow water to circulate through the radiator. If you have circulation below the t-stat opening point, there is your problem.
 
Are you sure you have enough water in the system. If your water is low, and yes it can be low and still show in the rad, you will get exactly the problem you are seeing. The car will warm up and you will get heat until the stat opens and your temps go down. I f you are low on water the temp will read low even though the engine is very hot and the heater will not work.

Jack
 
Doen't some get thru by design? So the bypass only circulates thru the motor.
Makes sense what you two are saying, however I think and I could be wrong, once we are talking about a hot open system, doesn't that sorta negate that?
On the other hand it should close off to keep the temp up but do you think once it's hot in the engine that the stat would ever really close fully again while running? I have never seen any engine run this cold even thru the years a couple times I had motors will no t-sat at all, going by that those got plenty hot so how could a little bypass in mine cause a 50 degree drop?
Don't take this as I'm arguing, I'm not, I'm just trying to get a mindset of how this could be happening, thanks.
 
I'm not explaining this right. The heater works perfect, no problems. The heat coming out of the vents reflects the temperature of the engine, so if the engine runs cool the heat coming out is cool, not useful for warming humans. If the engine gains some heat at a stoplight the heat coming from the vents reflects this rise in temp. Then I start moving with the green light and the temp gauges reflects that the engine is cooling off and the temp of the air coming out of the vents also coincides with this, meaning that the heat coming out of the vents is not real useful anymore. This only happens when moving, sitting in the driveway it has no problem getting to 190, until I start driving.
 
Also, the CTS is mounted in the manifold close to the T-stat in the front. There are no splices in the wire, it is inside a metal coiled sheath all the way up to the gauge as it came from SunPro. The water level has stayed the same, about a half inch below the filler and I have a recovery bottle, I also have a new 16 pound cap installed. The stock shroud is installed and the mechanical fan is half way in, I ran it for a bit before the shroud was installed because I was planning on replacing the radiator, after the shroud went on I lost most of the heat we're discussing but it never ran over 150 before the shroud.
 
PhillH said:
Doesn't some get thru by design? So the bypass only circulates thru the motor.
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NO... and YES. The only coolant that can flow to the top of the rad is through the t'stat or around it via problem in the t'stat housing. The bypass puts the coolant right back into the water pump input.

These cooling issues might be the source of your other problems.... it would explain grey condensation on the dipstick for example. Running so cool, the internals never get or stay up to proper temps.... like piston expansion.
 
I though about the condensation thing, I checked it cold today and your right, the grey is not in the oil, the oil is clean, the grey wiped of the dipstick above the oil line. I was thinking that from past experience it would look more like sludge, this looks more liike the fine grey matter that would come from a bearing. However with the engine being so new it may not have had time to turm to sludge. Also as I checked it cold today this was after I had checked it before and it hasn't been run in between, so the grey I wiped off the dipstick was not there and just clean oil on the dipstick. I pushed your Thanks button.
 
OK, well the brown condensation sludge is common once the engine has gotten older and brown varnish has built up inside. But I have seen it grey too...

The connection between the cold engine and the other problems is of concern. But it would not make the oil pressure lower....
 
That is why I jumped to my limited knowledge of putting these symptoms together, lower knocking noise, low oil pressure, the grey matter was the one that put me over the edge.
 
Maybe the stat is just too slow to close? But two in a row? IDK..... It's job is to control the minimum operating temp. It doesn't seem to be doing that.....

I'll tell you what I would do.
I would take the radcap off, and bring the engine up to temp at a stand-still. I would clamp the top radhose off, say 80%, put the cap back on, and take it for a spin.
If the temp goes up to overheat, remove the clamp, and let her cool off. Conclusion; bad stat.
If the temp goes down, conclusion; That's gotta be impossible. But if it does, that takes me back to my first post.
That's what I would do.
 
The coolant is getting by the tstat, either thru it, or around it. It heats at stop lites cuz the w/pump and fan slow down at idle, and the coolant gains temp till the revs go up which increases coolant and air flow speeds. Did you ever check the fit of the thermostat in the housing?

If you take your valve covers off, I think you'll find that grey film, and perhaps drops of moisture on the v/c undersides too.
 
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