I was towing with my V-10 through southern Nevada and my trusty autometer water temp gauge began reading in excess of 225 degrees! Is this overheating for the V-10? Also the 4r100 tranny fluid got to about 200 degrees. What is considered borderline fluid temps for these assemblies? My truck is a early 1999 V-10 w/ 4r100. Thanks!

 

Well, I think the engine has a 195* thermostat in it. When I tow, I start to back off around 205 on either the coolant temp, or the cylinder head temp as reported by the PCM thru AutoTap software. 210* would seem really hot to me - that's 15* above spec.

As far as the tranny goes, cooler is better. I was hitting 220 last month, and am looking for ways to drop that because the warmer it gets, the quicker the fluids breakdown.

I would be more concerned about the 225* of the coolant than the 200* of the tranny. But then again, I burned up to GMC 6.5L Turbo Diesels so I'm a bit paranoid on temps.

All of this info is my opinion - other may have more statistically based ideas.

 

225 is kinda hot - I'd start checking the fan clutch, the radiator (and AC condensor and tranny cooler) fins for bugs/leaves/crud, coolant level, etc.

I'm betting the fan clutch didn't lockup enough to cool the radiator...

 

What temp is the fan clutch suposed to lockup at?

 

Im gonna check out the fan clutch and backflush the rad/ AC condenser coils this weekend. Hopefully it helps. If not, i am thinking of getting the Cyclone fan. Any experience with it?

 

The stock fan, when working correctly is more than enough cooling for the Superduty.

I'd get the truck cool first, before playing around with new toys

I have no idea when the stock one locks up, I've only heard mine come on once, and it was when it was very hot out, and I was idling around pull stumps. The coolant temp never went above 200.

 

You must back off a lot!

The maximum spec is more like 240F. 195F is just where the thermostat is nominally fully open. It is NOT the maximum temp, it isn't even a relevant temp.

Ford's max on the trans is 220F, with short term (less than 30 minutes) at 250F. This is the temp in the pan or test port. The line to the cooler will be hotter than that.

 

Mark, welcome back!

A note to anyone new to the forums in the last few years:
Listen to Mark when he talks transmission. He really knows his stuff. (He should, since it's his livelyhood.)

 

Are you saying that I have to back off A LOT when coolant/cylinder head temps reach 205* towing?

 

No, I'm saying you must back off often because you back off at a temperature that is considered normal temps by the auto industry. You're backing of before the cooling fan is even going to be on. The engine and cooling system is designed to go to 240F with NO problems. Let the truck do it's job!

 

I've been waiting on that statment for some time now. I've heard so many people argue where the temp should be measured and I've always stuck with the pan or test port - it just seemed logical to me as the best "overall" temp reading.

Sorry I didn't mean to get off from the original post.

Now - I'm planning on adding a engine temp gauge, where is the optimal location for it?

 

Check my gallery. I took pictures of where I put my sender. It is a water jacket plug on the driver side of the block. You must use a water jacket adapter though, as the sender is deeper than the water jacket. The correct adapter is this one. clicky

 

Then what was this staement in refernece too?I don't mean to argue, but 240* seems way too hot. But, like I said, I burned up two GM 6.5 Turbo Diesels so I'm a bit gun shy.

 

240 on an aluminum head engine is quite high.

Mark, I see you've been here since 1999, so I'm not inclined to argue with you much, if at all

But 240? Yeah, with a pressurized system, it won't boil over, but that's still pretty high.

With a 195 thermostat, I wouldn't want to see more than 220, but that's just me And what do I know?

 

The lock up temp varies the harder you pull it on a hot day the more it locks up. Last month I was pulling in 101 temps and the fan can on low at first and then it sounded like I about to lift off, I think its the first time I had it locked up that hard. You well know if its working if its hot out and you are pulling it hard. I would check the A/C condenser and remove the top cover behind the grill so you can see the radiator. But if you are pulling on a hot day on grades and you don't here the fan it may be toast.

Denny