Sorry for the wall of words.

I bought this truck in early March of this year. Truck has 130,000'ish miles on it. It's an all stock 2003 2.3L XL with 5-spd manual trans, stock 225x70/R15 tires and 3.73 gears.

On my first dump run after buying the truck, when I got home both the degas bottle and radiator had sprung a leak. The degas bottle plastic was rotten and flaking. You could scratch away at it easily with your fingernail. On the radiator the end cap seal had given up.

I replaced the degas bottle (Motorcraft), degas cap (Motorcraft), radiator (Napa) and both radiator hoses (Gates). Took it out for another test drive and found another leak down by the starter. The original owner must have had the original plastic "T" crack and cut it out and replaced it with a clamp in style plastic "T". One of the screw clamps had loosened up so I tightened it and that solved that leak.

Took it out for yet another test drive but this time monitoring temps with Forscan and found that my ECT was around 222*-228*. Never got higher. Because I needed to replace the god for saken PCV valve and the truck had 130k on it I decided to freshen up the cooling system with a new thermostat (Motorcraft), waterpump (Motorcraft) and fan clutch (Haynes).

I got everything installed, filled it up with coolant, burped it for about 25 minutes and then took it for a spin. This time I used an ODB2 bluetooth adapter and Torque Pro to monitor the temps. During the short 2-3 mile drive I noticed the ECT go up to 270* and CTH up to 302*. I limped it back home and let the truck cool down. Once it cooled down I noticed a lot of coolant missing from the degas bottle and figured it had a lot of air still in the system. I topped off the coolant and put the truck away for the night.
I'm not entirely sure whether or not Torque Pro was giving me the correct temps or not. And at no time was there a white cloud behind me.

Yesterday morning I burped it for another 20 mins. I took it for another spin and this time monitored it with Forscan again. During the drive the ECT hovers around 232*- 240* and CHT around 262*-282*. The temps do fluctuate depending on load. During the drive and after about the first 2 miles I pulled over to check the coolant level and found the degas bottle had puked a little. Figuring it might be more air, I drove about another 4-5 miles at 50-55 mph and pulled over again. This time I didn't see any tell tale signs of puking but the temps still remained kinda high.

Sooooooo, yesterday afternoon I got a coolant tester. And this morning I tested the coolant while it was cold and it shows that my coolant is good to -35*F.

I feel like I may have messed something up by replacing all of the cooling system parts with new stuff. I know these engines run hot and this one seemed to like the ECT 222*-228* range before I went and replaced everything. Now it's in the ECT 232*-240*'ish range and I'm not sure if that's safe for these Duratec 2.3's. My biggest worry is that I may have popped a head gasket what with the puking of the degas bottle, but, I'm not seeing any white out of the exhaust pipe. And there's no coolant in the oil and there's no oil in the coolant.

I guess my next step would be to do a pressure test of the cooling system? Could the -35* reading cause temps to run a bit warmer than normal (more coolant than water)? I'd feel so much better if those ECT temps were back where they were. And that degas bottle puking just makes me nervous.

Thanks.

Cliff Notes: Truck sprung a leak. Replaced cooling system components with all new parts for a freshen up. Before leak, truck would run 222*-228* on ECT pretty solidly. After all new parts truck runs an ECT of 232*-240*'ish which seems a bit to high. Plus, after all new parts, degas bottle puked a little. No oil in the coolant and no coolant in the oil. No white cloud from the exhaust.

 

When you burped the system, was it up on ramps, or on a incline, the steeper the better & was the heater temp control on Max heat so you were getting good flow through the heater core, to chase any air out of it????

 

Thanks pawpaw.

I'm ashamed to say it was not up on ramps. My driveway does have a slope to it but nothing like a set of ramps could provide. I did remember to turn on max heat though.

I'll put it up on the ramps when I've got some free time and give it another burp.

 

Ok, raise it on ramps on the slopping driveway so the radiator is the highest point, with it fully warmed up, the heater on Max temp & run it at fast idle for say 5 min, so to chase any air back to the top side of the radiator where the radiator cap can burp the system on cool down. Then with it still up on ramps turn it off & let it fully cool down. If you'll mark the coolant reservoir level & it drops after cooling, you'll know it has burped some more. Leaving the hood up will have it cool down faster if your in a hurry for results.
Was the coolant in good condition, no rusty sludge on the flush???
Those temps if accurate are high, we're supposed to be running a 195 deg thermostat, so temp should be between that and say 205 on the high side.

 

The coolant is brand new. The first time (degas bottle and radiator replacement) was a complete flush and fill with new Zerex G-05. The second time (water pump, thermostat, fan clutch replacement) was a drain and then more brand new Zerex G-05.

The coolant that was in it at the time of purchase was the green stuff. I found out a little later that the engine should have had the gold stuff in it. The green coolant was pretty old and not in good shape. No rust or weird floaties in flush though.

The thermostat is a Motorcraft 190* but I read that these Duratec 2.3's run on the hot side due to the way the electronic thermostat operates. I'm still thoroughly confused about this engine. Heck, my 2006 F350 6.0 Powerstroke was less complicated than this thing.

 

When I did my cooling system drain and refill I somewhere found some very detailed instructions for the bleeding process. It involves raising rpm to a certain speed for specified time and for multiple times. Searched and cant find that info now. Do you own or have access to a service manual? If not some libraries reference dept have Alldata or Mitchells on Demand for free use in library and can print what you need. If you follow those detailed bleeding instructions and still have issues think you better test for potential head gasket issues. I think there are dye kits that can test for this. Maybe some others can chime in on other test methods. You have hit all the other potential causes that I can think of with your replacement part list.

 

Thanks Maz. I found the procedure you were talking about. Had to join AlldataDiy but I got it. I'll put the truck up on the ramps and perform that Ford procedure. I really hope it's not the head gasket. That's a road I just don't want to travel.

I know these types of cooling systems are extremely sensitive even to the smallest air leak. It is possible for them to allow air to be sucked in but not leak fluid out. If burping it via the Ford way doesn't work then I'll try a pressure test and if that checks good then maybe I'll try the exhaust gasses dye kit.

Burping procedure:

1. Fill the system through the degas bottle cap to the max fill level.
2. Start the engine and run for approximately ten seconds at 2,500 rpm to prime the heater circuit then turn the engine off.
3. Top off the coolant level to 0.6 inch above the max fill level.
4. Install the degas bottle cap.
5. Start the engine and hold at 2,500 rpm engine speed for approximately eight minutes until the thermostat opens.
6. Maintain 2,500 rpm engine speed for an additional three minutes.
7. Increase engine speed to 4,000 rpm and hold for five seconds.
8. Return engine speed to 2,500 rpm and hold for an additional three minutes.
9. Repeat the previous two steps.
10. Stop the engine and check for leaks.
11. Verify correct fluid level after engine cools for 20 minutes. Top off the degas bottle to "max" line.

 

rev limiter kept me from hitting some of rpms stated in instructions. get as close as can to rpm without engaging limiter.engine will start surging up down when it happens. hope you cure it with this bleed process

 

Ok, I put the truck up on ramps this morning and burped it exactly as outlined in that procedure. Then I took it on a 60mi round trip to the in-laws.

No puking from the degas bottle but the truck is running hot. Speeds were between 35mph - 55mph and temps there were between 228*-240* ECT and 256*-275* CHT. Outside temp was 52*. The idiot temp gauge in the dash runs a hair on the high side of the middle to about 3/4 of the way to hot.

What's really strange is that when the truck is cool it has plenty of power. But as the truck heats up it gets slower. On the longer hills (these are not large hills), I'd have to drop to 4th gear to barely keep 55 mph and even then it would start bucking. On the largest hill (still kind of small) I couldn't even keep 45mph in 3rd gear.

I checked and the brakes aren't dragging. And the air-conditioner condenser fins are all in really good shape so it's not an airflow issue.

While cruising, the 1st o2 sensor was cycling and looked normal as far as I could tell. The 2nd o2 sensor was pretty steady between .7#v and .6#v.
It's been quite a while since I've needed to watch o2 outputs so I'm still kinda vague on what I should be seeing.

I'm going to check tomorrow and see if the IMRC actuator rod popped off again but if it hasn't I'm clueless as to what the problem could be.

 

OK, so what happens to the monitored coolant temp when you set the dash heater temp control to Max heat & turn the fan speed to max, does the monitored coolant temp come down & if so, how much???

 

pawpaw,

Funny you ask because I tried that on the way to the in-laws. I cranked it to Max Heat and turned the fan on full blast and the engine temp never went down even after a few miles. And I did not get that antifreeze smell so I'm 95% sure my heater core doesn't have a hole in it.

On the long downhills the temp would recover (228* ECT / 256* CHT) but then hit a long flat spot for a cruise or hit another hill again and the temps would go back up.

Something else I noticed; After performing the burp procedure where it tells you to stop the engine and let the truck sit for 20 minutes. Well, right after I stopped the engine I got out and touched all of the hoses. The top radiator hose was very hot. All of the heater hoses were very hot. The bypass hose was hot. But the bottom radiator hose was as cool as it was outside. Sooooo, once I got to my in-laws house, I did the same thing again. Again all hoses were hot except for the bottom hose which this time was just warm.

These 2001-2003's are a real anomaly with their extremely hard to understand electronic thermostats. I don't know if I'm losing power because the engine is too hot and it's pulling timing to avoid knock or if that's the normal temp range and I have another issue.

 

Ok, good feedback but I gotta think about this for a while. Maybe if tomw or others more familiar than me with the innards of the 2.3L are following this thread they'll chime in with thoughts.
If the temp sensors are correct, this puppy seems to be running hot for some reason & with all the new quality parts it shouldn't, unless one is faulty, or you have another problem, like a flow volume problem, head gasket leak, or a head & block heat conduction problem from deposits like scale, or sludge insulating things from the previous owner using the wrong coolant for a long time .
Right now without more clues it seems without more consideration, the new thermostat also belongs on the suspect list. Those measured temps aren't good for the engine, or oil.
Is FORScan finding any other trouble code clues, or does fuel trim or other parameters seem to be close to being out of range????
Have you performed a cooling system pressure check???
Have you used a optical/thermal heat sensor/gun type thingy I can't think of the proper name right now, but you aim it at various parts to measure the surface temp of things. Anyway have you used one of those to measure temperature of various locations on the engine block & head, to see if one area is running notsbly hotter, or cooler than the other, as maybe that could offer up ideas on where to look closer for clues to what's going on.
When you did the coolant change, you said the old coolant didn't look good, but didn't find any rust, or sludge in what was removed, but did you run a known good quality descale, or other cooling system cleaner upper product & flush routine, before installing the new coolant, or did you just flush with tap water, drain & add the new coolant???
More rambling thoughts for consideration, keep us posted on your findings.

 

Thanks pawpaw, I really appreciate all of your help on this.

I'm going to retest the sensors this morning and see if they jive with the ambient temp.

FORScan only finds one trouble code; B1352 - "Ignition Key in Circuit Fault". As for the fuel trims, I'll take it for another test run today and see what they read.

I ordered up a cooling system pressure testing kit yesterday which should be here by the end of this week or early next week. None of the local auto parts stores have a loaner available.

I do have an old cheapy non-contact IR gun that I haven't fired up in years so I'll go throw a new 9v in it and see if it still works. Just have to find it.

I didn't run any kind of cleaner or descaler through it when I flushed it. I just ran a garden hose full blast through it for about 10 minutes. Then flushed some more with about 7 gallons of distilled water before adding coolant.


Something else I found in my quest for a normal temp range:

I'm going to check and see if the heater circuit for this thermostat is actually working. I know it's fuse 2.41 under the hood and I know it shares power with the IMRC solenoid and the EGR and I "believe" both of those are working and so I'll try and find a way to test power at the thermostat.

 

Ok, more good feedback & info. Seems you've done some informative research & have a good grip on your trouble shoot, so continue to let us know how it goes, we all learn from good feedback.
By chance is the battery & charging system in good shape, as the computer figures in a good bit on all of this, so it & the sensors it uses to control things, need a good steady, in spec electrical supply, that has good clean ground connections, lest they cause mischief!!!!

 

Ok, so, I took it for a test run with my handy dandy no-contact IR gun. I'm not entirely sure how accurate it is but my forehead temp reads 94* with it.

Any way, after a few miles of driving the idiot gauge was on the high side of the middle. I pulled over and got out the temp gun.

- The upper radiator hose read 170'ish*.
- The bottom radiator hose at the radiator connection and thermostat read 80'ish*.
- All of the heater hoses were reading 200-210*.
- The overflow hose down by the thermostat was reading 180'ish*.
- And.....the steel tube that connects to the other steel tube that connects the upper radiator hose to the back of the head back by the firewall was 228*-240'ish* depending where on the pipe I had the gun.
- I even tested the degas bottle and it was reading 170'ish*.

The emissivity of the temp gun is set to .95 (what ever that means). But I'm not sure if it will read the temp of the degas bottle correctly.

So from this, it looks as though the big temps come from those two steel pipes (PN's 8592 and 8K556). Those pipes connect to the head and sit above the exhaust manifold. Those two pipes also have connections to the heater core and the degas bottle in addition to the top radiator hose.

Regarding the charging system, the battery is brand new, the + and - cables are in good shape with no corrosion showing. And when idling and cruising, FORScan indicates 13.6v-13.8v. The truck starts like a champ every single time.

Now, maybe a little off topic but I started going IR gun happy and decided to test the exhaust. Each exhaust manifold runner was somewhere between 350*-450*. It really fluctuated. But, they were all really close. The collector was 630*. Then I tested each catalytic converter and the first one was about 550* and the second about 480*. Then moving back the temp went down to about 230* at the first connection point. But then, right at the resonator the temp shoots back up to 350*. The connection between the muffler and resonator was about 320* and then the pipe after the muffler went from 230* down to 120* at the tail pipe. I'm not sure why there is a temperature spike in the pipe connection right there at the resonator. The pipe does seem to neck down a little at that connection so I'm not sure if that would cause a temp spike.

EDIT: Ooops, forgot to mention that I was monitoring Fuel Trims too. LTFT was fluctuating slowly between 0.## -> +3.## depending on conditions. STFT was fluctuating pretty quickly between -3.## -> 0.## -> 3.## and again, depending on engine conditions. I'm not entirely sure what those numbers mean or if it's any good.

EDIT#2: Accidentally had two STFT's set up in FORScan. Once I selected the proper LTFT it was reading +6.##