Lately, it has been pretty warm here in Tx. This past weekend, my temps were running between 204-220 driving down the highway. As soon as I would slow down less than 30, temp would rise fast. At stop lights, if I sat more than a minute, temp would hit 232 and Edge Tuner alarm would start going off.

Is this normal running temps for 05 F-250 6.0? I had a 03 F-250 same engine in SOCAL and never had that problem, even pulling trailers through desert of AZ.

Plan on doing coolant flush this afternoon. Just on drive to work this morning when it was 78 outside, coolant temps cycled between 210-228.

 

Check your fan clutch, also check your coolant levels

 

No not normal... Bad thermostat maybe? Don't think a flush will do much for you...is your engine fan coming on?? Should be full roaring at 216-218...

Unloaded in 100+ deg here in SoCal running up and down hills and traffic I will sometimes see 210ish on the high side but usually around 200.
Towing my 28' toy hauler loaded across the desert with temps 100-115 my engine will hit 220-225 while climbing a hill but on flat they will cycle between 205-220.

 

I stumbled across this thread (starting at post #832) where a guy seemed to have some good results with a product called 'Thermocure'. It's supposed to dissolve all the gunk and rust from your coolant system, which acts like a slimy insulator as it builds up on your coolant system internals over the years. Since it's gooed on, just a flush won't help terribly much. The thermocure is supposed to dissolve all that gunk so you can flush it out and the coolant can cool things down better. I've never tried it myself, but it might be worth a look.

 

I would not do a flush like that in a 6.0l unless you were planning on doing and oil cooler right after. Chemical cleaning (vc9 or similar) the cooling system on a 6.0l will dislodge all the crap and plug the oil cooler.

 

It's meant to dissolve the stuff, not just knock it lose. Besides, if you don't get rid of it properly, it'll just build up and could dislodge a bigger chunk later down the road.

 

That's the idea, but it never happens that way. I had a cooler that was seeing 18 degree deltas, I flushed the system with VC-9 and after about 300 miles of driving, my deltas climbed to 20 while sitting still at idle. If your cooling system hasn't been maintained properly, you WILL have this problem if you flush. I was prepared with a new oil cooler beforehand and knew this would happen.

 

Agree with Thor, you shouldn't be using any chemicals unless you're planning on a new oil cooler. And even then, I wouldn't use anything but Ford VC-9.

Don't skip steps though. First priority is to find out why your cooling fan isn't roaring at those temperatures. It may not completely solve the problem, but it's definitely an issue if it's not cycling on. Troubleshoot that and then look at the cooling system.

 

changed out coolant yesterday; didnt do a complete flush. drove to work this morning and temps never got above 198. will monitor this afternoon when it really gets hot outside.

had the truck for 3 months, so no guarantee what previous owner may have had in the system, but i know what is in it now.

thanks for all the responses.

 

You can check the fan clutch by grounding a wire in the fan wiring connector:
https://www.ford-trucks.com/forums/1...l#post16370574

It should start spinning within a minute or so, and if you rev the engine it should sound like a semi truck

You can also check fan clutch duty cycle on most digital gauge setups, PID is FDC. By 220*f ECT it should be 100% locked in.

 

Good info. I posted a thread about this a little while ago without any decent response. I put a new used clutch in my fan and haven't seen it come on yet with temps about 220ish.

 

At 215-217, it should be roaring. Do you have a sticky residue on your fan shroud aft of the fan? It's very likely that all of the viscous fluid leaked out of your clutch. I have replaced mine twice in the last year, mostly because the new clutches were stored improperly, and allowed the seal to leak. They should be stored with the slip-ring down. If it's been sitting with the slip-ring up, it will leak out all of the fluid in a short time.

FYI; don't buy this used or from ford. Ford stocks remanufactured units that come from the same exact company that remanufactures the same units for autozone, except for autozone has a lifetime warranty and the clutch is $100 less than Ford.

 

If it happens to be a bad fan clutch I HIGHLY recommend the Bulletproof diesel 7.3l fan clutch adapter and using a 1997 7.3l mechanical fan clutch!! I put one on a few months ago and I cannot be happier with it! Keeps the truck running cooler loaded or not! I was shocked how much cooler and consistent the temps were especially when towing. Ford should have done this from the factory! Also as a bonus I have noticed my AC is colder now especially in traffic...

 

Out of curiosity I did a little check on my rig today. Ambient temps were 95f this afternoon. After warm up driving at 60mph on flat roads, engine coolant temps were 195 to 197 steady. Fan speed at these cruising speeds was between 450-460rpms.

Come to a stop and after about fifteen seconds fan speeds would jump up to around 875rpms. Interesting though, the longer I sat there in gear stopped, my engine coolant temps would DROP to around 192f. I had the A/C on MAX the entire time. And It was getting cold in my cab. Brrrr.... Just saying. LOL. B.

 

More good info. I will look for the sticky residue. So if I try this grounding the wire thing and it doesn't come on I guess my new used unit is no good? I did hear something about storing these properly but didn't pay too much attention to it. The mechanical unit sounds good. I have never heard of that.