Another Thermostat

RBBailey

NAS-ROW Addict
Callsign: KF7KFZ
Well... I have now been into the thermostat housing four times to try to see if I can find a leak, or switch the stat to something that works right. Today I put in the new Motorad 319-180, and it did not make for any change. After driving for about 20 minutes at 45-60mph, it was still only at about 160 degrees. It climbed to break that 180 degree mark when I went up hill for over a mile at over 60 mph. Once I got to my own hill, I climbed 800 feet for a mile at 20 mph, this brought the temp up to 180 again, as it had quickly fallen back to 170 when I got off the freeway.

While the truck was idling, and showing 180 on the gauge, I took the following video:https://flic.kr/p/PpeYsM
(You can also hear my wonderful bell ringing that I'm totally ignoring. Totally.)
 

Napalm00

Technical Excellence Contributor
This is the first video I can actually hear your bell ringing. It just sounds like pre detonation pinging to me. Did you ever get around to checking the timing with a gauge?
 

RBBailey

NAS-ROW Addict
Callsign: KF7KFZ
About 45-50 degrees.

I have the dial gauge. That’s the next thing. What I really have noticed about the ringing is that it doesn’t make the sound till the engine gets some heat.
 

Viton

Well-known member
These engines, any diesel for that matter, do cool down quickly. Engine temperature is highly dependant on the amount of fuel you're burning, providing your cooling system is working correctly. Unlike a gasser, idling is the best way to cool one down. If you get a 319-192, that is the stock T-stat for this engine. Remember the T-stat sets the bottom operating temperature, if you idle & run your cab heater, the engine temp will drop lower. If you want one that's hotter (I'm running a 203F) you'll have to build it. I have built, 198, 203, and 205 using Motorad parts. Only in the summer do these engines run at about the T-stats rated temperature.
IF you are going to experiment with hotter units, you really need to get a VDO temp gauge & corresponding sensor. I saw in your movie, your IR gun, be sure to get a good one, most are +- 5 degrees or higher, that's not good enough. You need one that's +-2 degrees & measure the temp where the sender is in the T-stat housing.
Also when you get a new T-stat, put it in water on the stove and using your IR gun, measure the water temp when you see it open, they can be way off or even dead, non-functioning or quick to open or slow to open. Running you engine under 210F degrees won't hurt a thing.
 

RBBailey

NAS-ROW Addict
Callsign: KF7KFZ
I suppose it isn’t ‘bad’ that I’m under temp, but something doesn’t sit right with me when I think that 90% of the drives I do it never opens the ‘stat, at least not all the way. On a gas engine, at least, I would want to get some carbon burn temps once in a while. Also, with winter coming on, I need as much cabin heat as possible. Right now it is inadequate if the temps were in the low 30s. Also, don’t these engines run more efficiently at higher temps?

I suppose I could try a 190 unit to see if that extract 10 degrees of close time gets me up more.

I put a cover over 3/4 of the radiator, and will see if it makes a difference. I think last year it did bring the temp up quicker, but except for when under harsh conditions, it still topped out at 180 or 185.

I have a VDO gauge and sender. The VDO was just a hair above 180 when I shot the video. I wouldn’t expect to see 180 when measuring off the outside of the engine, but being within 5 degrees seems legitimate especially after only 20 minutes of run time.

Remember, this is with no fan. And even in summer months, it takes a good 10 minutes to get to 180.
 

Viton

Well-known member
Try the Motorad 319-192, but even when I ran that one the needle would barely reach the 190 F line on the VDO. Knowing that Ford runs 215F in their diesels as OEM, I tried boosting my temp up. The 205F I built runs the engine at 209F, but the distance on the VDO from 210 to 220 is very short and I don't want to get near the 220 mark.

Do a Google search on VW diesel thermostat builds, these guys build hotter T-stats too to get their engine to warm up faster, run better and keep the cab temps warmer in the winter. My engine, when warmed up, responds much better when than cold.
Again, I run a 198F in the summer and the 203F in the winter.
 

RBBailey

NAS-ROW Addict
Callsign: KF7KFZ
As expected, with 3/4 coverage on the radiator, my temps came up faster this morning, but only reached 175 by the time I was idling in my parking spot at work. It's only a 6 mile drive. At 175, I suspect the stat is starting to open?
 

Viton

Well-known member
At 175, I suspect the stat is starting to open?

T-stats can be several degrees off, high or low. Again the T-stat sets the minimum operating temperature of the engine and should not open until it's reached. I'm pretty sure Motorad's tolerance is plus of minus 3 degrees Celsius, converted to F ( 1.8 x Celsius) that can be almost 6 degrees off, high or low of your 180F T-stat.

Always test a new T-stat in a pan or boiling water before installation.
Do it this way.
While the water is cold, submerge the T-stat in the water with the lid off.
Stand there while the water heats up, watch the T-stat valve, measure the water temp with your IR gun ad the valve starts to open and again when it's fully open. If it's defective, it may not open or only partially open. You'll also know the temperature of when it really opens. If you want to get real exact, water boils at a lower temperature at higher elevations than at the standard 212F degrees which is at sea level. You can Google this to read about why this happens.

On the Motorad, the degrees is stamped into the base of the wax pellet.
On your 319-180, that is located in the "hole" on the bottom, you may need good lighting to see it down in there.
 
Top