Running no thermostat (constantly flowing coolant). What can that do?

timewarped1972 said:
ok when you ask the parts people for 180 t stats, sometimes they say they dont have them because it isn't listed as a replacement part.
try one for a 65 mustang or basically and thermostat that will fit a small block ford should work.
Or I will look the part up on a store's online site, write down the part number and take it with. Then when you get a look like you just asked for a flux capacitor for a time machine, you can provide the part number and they can look it up that way.
 
I had a motorcraft 180* and I drilled a 1/8" hole in it. When I had that thermostat in, I had the bleeder hole facing the 12 o'clock position. Can you get the mr gasket stat locally?
 
David, I have seen parts store stats with the jiggle valve (what the bleed valve is called). Not sure on Napa or Motorcraft stats though.

David, I keep a spare Mr G on hand (a 180) that I can ship you if you want.
 
For those who are not running t-stats there is and optimum range of heat for which your motor runs most efficiently. Running below this range can have the same type of performance loss as running over it. Just a thought
 
5spd GT said:
James - Ooppsss...I didn't turn on the heater. I just removed the cap, turned the car on, and let it heat up to midway on the guage, shut the car off, put cap back on and went from there. So could the heater not being on do that?
Well, if you've watched the radiator for flow to see when the thermostat is opening, then I doubt the heater thing is your problem. Basically, without turning the heater on, you could allow air bubbles to be trapped in there and get back into your system.

You could hook a voltmeter to the ECT sensor (sensor on the heater pipe - I believe it's the LG/Y wire) and watch for ~.61 volts for a 195 temp, or ~.77 volts for a 180 temp to tell you what temp the motor is when the t'stat opens without relying on your stock gauge, or any other gauge for that matter. Of course, you'd have your rad. cap off and watch for flow to come out and simultaneously be watching your voltmeter to see the voltage and then tie the voltage to the temp.

FYI

158*=~.1.04v
176*=~.80v
194*=~.61v
212*=~.47v
230*=~.36v
(Source: How to Understand, Service and Modify Ford Fuel Injection & Electronic Engine Control by Charles O. Probst, SAE)

HISSIN taught me to jack up the front drivers side of the car - if I remember correctly, it's to get the Thermostat higher than the rest of the motor, but I always get confused on the reasoning, I just do it:) - and let it warm up like that w/ the heater on, cap off. Top it off, let it cool down and take it for a test drive and see if it overheats and go from there.

I say all of this because the stat may not be 100% of your problem. A good burping will do no harm, anyway:nice:

Good Luck
 
Drilling some holes in it isn't a bad idea David -- the t'stat acts as a flow restrictor as well as controlling op temp. The holes will let some coolant through without letting too much through. But if it's just a couple of weeks you're trying to get through -- I wouldn't bother if you have another car to drive.

Be sure to test the new t'stat in a pot of boiling water (preferably use coolant) with a thermometer. You can check to see that it opens and that it opens near the temp it's supposed to. A lot easier to test them that way than to test them in the car and find out they're not working correctly.
 
I ran without a tstat for 2 years it ran like crap at every start up but now with the 180 runs like a champ.


BTW car over heated and needed a new water pump so replaced it with a tstat this time.
 
James - Thanks for the voltmeter info, I didn't know that:nice:

Michael - Yeah I'm just trying to get thru a couple weeks (highway driving). This is my only car. All other cars in my family are being used. I'm probably either going to remove it or drill in it.

JT - Your to kind:) My car will be alright and the offer is much appreciated:nice:

I think changing the thermostat is easy and pretty quick so I'm going to try it without it and see what it does (almost out of curiosity) and then I might just try drilling a hole in the t-stat. I'm going to test it...

To some of the others, I'm not looking for performance and I am only doing this for 14 days:D
 
PRO50SC said:
Couple of dumb questions for you.
1. Are you installing the t-stat in the correct direction?
2. What is the condition of your radiator?
3. What is the integrity of your fan set-up(clutch or electric)?

Yep, spring facing towards the intake

Radiator cools awesome (a bit over a year old griffin)

The fan doesn't effect in on the highway...it cools awesome till the t-stat started screwing up...
 
David, the very last thing I can think of, which probably does not even apply, is to ensure the lower rad hose has a spring in it and that it is not collapsing.

Good luck man.
 
fyi - this time of year, highway miles are probably the worst scenario for no t'stat. You have mega-air crossing the rad, and nothing to modulate how much heat gets removed. You'll be running REAL cool -- the efi will think the car has just been started pretty much the whole time. Probably won't hurt anything -- you'll get worse gas mileage. A bit of cardboard over some of the rad can help (yup -- and in Arkansas I'll bet that won't look out of place one bit :) ) -- but running too cool is a much better alternative than overheating - so I'm with ya. If ya gotta drive it - ya gotta drive it.
 
HISSIN50 said:
David, the very last thing I can think of, which probably does not even apply, is to ensure the lower rad hose has a spring in it and that it is not collapsing.

Good luck man.

Ha, the only time I have ever seen a lower hose collapse was on the highway doing 140+ at 5700 rpms, I know that alot of people say to check this, but is this truly a concern? (By the way this was in a series one and the highway was not open to the public... i am not that stupid anymore)

Then again I live in vegas where we change our hoses when we change our oil. To test for a suspect hose, rev your with the coolant flowing and hold it at a higher rpm, if you can reach down and compress the hose it is no good. On my 65 one time after a autox event the spring on the lower hose was actually partially outside of the hose, so I guess that hose collapsed on me too. Gotta love engine diapers
 
I recall reading in a highschool auto shop text book that if an engine is run too cool,170-175 approx*F or,(much)less,that cylinder bore and piston ring wear will increase at a faster rate.

If it`s run too cool you will most likely get worse fuel economy,a very poor/non functioning heater,engine sludge build up.
Not worth it.
 
Don't EVER Run Without a T-stat

8950HO said:
I recall reading in a highschool auto shop text book that if an engine is run too cool,170-175 approx*F or,(much)less,that cylinder bore and piston ring wear will increase at a faster rate.

This is very true, and is too often overlooked.
I've read several SAE, peer reviewed, and published papers that show how bore wear will increase as coolant temp decreases. This rate of gain is exponential. As your coolant temp drops below 180 the bore wear increases very fast. This is part of the reason for cold starts being so hard on motors.
Not even race cars will run without t-stats.
Running without a stat is one of the worse things you can do for the longevity of your motor. Probably worse than not changing the oil often enough, or not using a strong enough mixture of anti-freeze in the coolant.

5-spd GT
I would suspect that the sudden onset of problems is due to a faulty part, other than the stat. Especially since you have replaced the stat, and it did not resolve the issue.
My suggestion; Look for very small pinholes in the coolant hoses. Not only will coolant leak out when the system is hot (and internal pressure is high), but air will leak in as the system cools (which results in a decrease in system pressure). The air then sits in the coolant passages until the next time you start the car. Then, the air will prevent the flow of coolant by blocking the water flow.
I have had this happen to me when I had the stock 302. One of the heater hoses was the culprit.

I realize that many will spout out a bunch of crap on the internet, without knowing what they are talking about. I assure you, I have read several hundred papers at this point, most written by engineers for major auto manufacturers, most of which discussed oil and coolant temps. You do not want to remove the stat all together.

I wish you luck.
jason
 
Some more info

I doubt it will be read due to its length, but here it is just in case. It may help.


Unless you have some odd-ball combo the 160F (or lower) stat will do more harm than good. The lower cylinder temps will increase bore wear, engine oil will not get up to temp, and power and economy will most likely suffer due to poor combustion. Depending on the source, ideal coolant temps will be anywhere from 195F to 220F.
Most people feel that the 180F stat is a good compromise. I ran one for several years in a stockish 302, with no noticeable problems.
Hope this helps by bringing up some of the factors to consider when changing the coolant T-stat.
The literatures I have read (mostly SAE published papers) tend to indicate that the engine is most efficient around 200F coolant temps. The coldest coolant temp I have seen for any test (whether analyzing power/emissions/economy) has been 190F, anything lower seems to be considered cold start. The highest temp I have seen in a test is 240F. At 350F the glycol coolant degrades to form corrosive acids. The 350F limit is a local temp, for example in the head, between the valves. I am unsure how to correlate the 350F max allowable temp to ECT sensor readings.
Coolant/water mixtures should be at 50/50 whether using ethylene glycol or propylene glycol. I have seen SAE published papers that tested different ratios between 30/70 and 70/30. The best all around performance tends to be at 50/50.
Water is a better cooling fluid than the glycols, but does not provide the corrosion protection.
Another danger with straight water, which is hardly ever mentioned, is Cavitation. Cavitation damage occurs when the coolant experiences brief low pressure, followed by a return to high pressure. This situation is primarily found in water pumps, but is also common on the coolant side of cylinder walls of diesel engines.
As the pressure drops, the coolant forms small vapor pockets. When the system pressure increases, the vapor pockets collapse. The collapse releases a large amount of energy, which can damage the surface of metal materials. Think of a bubble popping, but with much greater force. By raising the vaporization temp of the coolant, glycol additives will help prevent cavitation. Using a proper radiator cap pressure will do this as well, as increasing the pressure in the entire system will provide protection against local low pressure zones.
 
Camman, more than one guy on here has found the lower-radiator-hose spring wedged inside their water pump. That tells me there is some dynamic going on for some folks. If a spring can be moved like that, I would imagine the hose could collapse were that spring not there......

David has a nice combo and likes to get on it occasionally, hence the suggestion. :)