Troubleshooting and repairs to date

1. replaced water pump and thermostat
2. radiator is 1 year old
3. flushed engine out with water (thermostat removed)
4. fan clutch checked, good
5. replaced temperature sending unit - to dashboard gauge
6. checked for combustion gas in water - looked for bubbles, also cranked engine with distributor disconnected.
7. new radiator cap
8. oil looks great, trans fluid looks great.

At idle on a 55 degree night, the engine settles in at the high end of the NORMAL range of the dash gauge..in fact right on the L.

Engine is allowing small amounts of coolant to bypass cap, this behavior comes and goes.

thinking about cleaning the condenser, trans cooler and other cooler in front of radiator...but I don't think this is root cause.

 

Is this something that has recently started? And how is performance, no guts, gas mileage gone for a dump? I had that, along with overheating last year. Turns out the PIP connector was corroded, so engine would not come off base timing, no spark advance. Check with a timing light, if timing does not change as engine speed varies, you might have same problem, severely retarded ignition timing. Remove the spout connector by base of distributor, and clean the male and female ends well
Good luck
Jeff

 

Prior to the water pump, thermostat and back flushing, it was overheating badly at idle.

Now, it runs at the L of NORMAL on the gauge at idle, at 65 MPH on 70 degree night, it was at the edge of the normal temperature range.

I will check the timing....

 

Have you had it to actually boil over? if not then
Buy a mechanical temperature gauge and check the actual temperature.
I believe the IVR is bad on my van because my oil pressure gauge also goes way up when I first start the van. After the driving for a while the oil pressure drops down to normal range. If I stop at a store and restart the engine, the oil pressure is high again for a few miles.

The pictures below show the difference between the two gauges. My dash gauge is defiantly way off.. Also if you have a laser thermometer that can be very useful. You can check the temp right at the thermostat housing ans see what temps it is operating at along with hose temps or the intake manifold right where the temp sender is..

Here is my stock temp gauge reading under normal driving


This is with a mechanical gauge after pulling a hill and coming to a stop

 

I bet that freaked you out until you figured out how wrong it was.

 

Yes it did because it started doing it right after I bought the van. First I changed the temp sending unit and the gauge went up a bit higher after that. I checked for combustion gas in the radiator twice and it was negative. I used a infrared thermometer at the thermostat housing and and intake manifold and it was normal. So were the hoses. I had the radiator vatted rodded out and still no change.
Thew mechanical gauge made the difference.

Now someone suggested the coolant passages in the cylinder heads could be blocked and that does happen, especially if one sits for a few years, but it is doing ok now.. SO I am guessing it is the IVR in the dash. My oil pressure gauge doesn't seem right and the fuel gauge goes way past full.. I haven't changed the IVR yet but plan on changing it and the odometer cable and instrument cluster bulbs at the same time so i only have to pull the dash once.
Oh I also installed a heavy duty fan clutch which helped to keep the temps down at lower speeds and found a 192F motorcraft thermostat online. All NAPA had was 195f.

I was getting occasional bubbles with the radiator cap off but guess that was possibly from the fact that the van was at a very slight angle and the air could have been trapped in the corner of the radiator.


I used the combustion gas tester and it was negative because the fluid never changed color.


The only thing I have left to change is the water pump but I haven't done it because I have read too many stories about the bolts breaking so maybe I'll wait till it starts leaking... I would recommend if a engine is high mileage, to change the timing chain and gears when you take the pump off!

 

I installed an electric coolant temperature gauge and ran the vehicle tonight 65-70F outside air temperature
At idle measured 205F
At 35-45 MPH measured 210F
At 70 MPH on highway it was running 220F
dropped back down to 210F off the highway.

I am discounting the transmission, since its 205F at idle.


Also, the new radiator is a 3 fin design (I think the next step up would be a 4 fin diesel..but pretty expensive).

 

besides hitting boiling point of the pressurized anti freeze/water, is there a max temperature the engine can run at?

 

Remember water boils at 212 deg F. So you need to worry if it exceeds that temp. what temp thermostat did you install? A 190 or so will let water heat higher to fully open.

I installed a gauge pod with oil pressure and water temp gauges from Glowshift. Both are electronic add ons. The water temp is spliced into the upper rad hose and the oil pressure is taken from an adapter that screws onto the oil filter housing and sits in between the filter and the housing. Seems to work as advertised and resolves temp and oil pressure concerns.

 

The radiator cap is supposed to maintain cooling system pressure at around 13 psi (check your specific application).

Then the coolant is supposed to be a 50/50 mix of antifreeze and distilled water.

The combination of antifreeze and system pressure should raise the boil over point to about 265* F.

The factory gauges are notoriously inaccurate and the instrument cluster voltage regulator (ICVR) or a bad ground are usually the culprits.

Using a point and shoot infared thermometer to check the actual temp at the thermostat housing when in doubt is excellent advice as is installing a more accurate aftermarket temp gauge.

I wouldn't worry too much about anything 225* (if you're working it hard) and under if the cooling system has a good mix of antifreeze and is holding correct pressure.

 

Make sure there's a spring in the lower radiator hose to keep it from collapsing.

 

Something I was thinking about is the gauge and sending unit accuracy. If you could rig up a way to test it in boiling water you could find out if it is reading correctly. There is so much junk out here these days I am learning not to trust any of it!
On my 5.0, using a infared thermometer on the intake manifold right where the sending unit screws in, reads higher then the actual temp because of the heat from the cylinder heads. The most accurate reading I got on mine was right at the thermostat housing. You can see the actual temp changes as the stat opens and closes. It should be fairly close to the thermostat rating.

In dealing with my 5.0 I wound up with 4 thermostats. The original, NAPA 195f, and 2 Motorcraft 192F that Ford specs for my engine. I tested all of them in boiling water and got different results from each of them. At 212F “only 1” was opened enough to get the probe of the thermometer between the gap. I am guessing the probe diameter is about 1/8“ to 3/16“. So at least the 4 thermostats I have, do not began to open till they reach the rated temperature and not all of them did that! SO I think that the thermostat begins to open at the rated temperature and with my van, it seems to be opened all the way (or at least what is required) at about 205F, and that is with a 192F stat. With the 195F stat, the temp went up to almost 210 on the same interstate up hill run with the outside temp at 95F

I replaced the thermostat in my 1985 E150 and a month later the engine overheated within 2 miles of the house while the engine should have still been cold. The new thermostat was stuck closed!
So it is possible that the NEW thermostat is off.

How many miles are on your van?

Your temperature range is within 15 degrees F which is similar to mine but mine only gets high when pulling hills on the interstate, once back on a flat the temperature drops back down. OR, while climbing a long grade in OD, if it kicks down out of OD, the temps will drop to normal. OR, in my test strip on the interstate by my house, after climbing the hill and leveling off the temp drops to 192F but then the exit is right there and coasting down to a stop, my temp goes back up.
here is an example of that. But it cools back down after I start off again.


My 85 van with a carb does not seem to vary like this, it pretty much stays steady.

So I have been concerned about mine especially after I replaced the AC system. The AC system does not seem to affect mine except at idle the temp will go up about 5F.

Besides timing that has already been mentioned there are a couple of other things that I have not seen mentioned yet. I bought a new Motorcraft O2 sensor last year and have yet to change it.. (if I didn’t have running boards I would not have to jack it up).

My other thought might be to check the Catalatic Converter. It is my understanding that the engine temperature will rise at highway speeds due to back pressure is the converter is starting to go bad. As it gets worse, you loose power...
Here is a good link about checking the cats..
Catalytic Converter

The only other thing I am thinking of right now pertains to the air flow..
I installed a heavy duty fan clutch which you can hear working when the engine is cold and the van is first started. It also kicks on after coming to a stop and starting off again. On my van it will usually stay kicked in till I get up to about 40 mph. Once over 40 mph the fan quietens down till you come to a stop again.
When the fan is kicked in the temp will drop to about 192F and stay there as long as I stay in the speed range to keep the fan clutch engaged.
When it is raining, the temp stays right around 192f around town. I have not driven it on the interstate yet with it raining. Out of curiosity you might want to use a hose and spray some water in from the front while watching the temp gauge..

 

Is the fan shroud still present and in good condition, or has it broken with pieces missing, or has it gone bye bye?

 

220-230 is fairly high for a steel block and is close to maxed.
Oil temp is more important

do you have a shroud?
How did you check the fan clutch?
http://www.aa1car.com/library/cooling_fan_clutch.htm
not my way but

 

Yes it has a fan shroud, which is intact. The fan clutch is working - pulling air well very well at idle. At 70 MPH, I wouldn't think the fan clutch is as critical, I believe they are mainly for below 35 MPH.

The factory temp gauge ran up to the high range of normal. The aftermarket gauge with temperature readout seems to agree with this.


I still need to check timing.