Overheating and Clutch Failure

[HadAFalcon]

My 92 Ex runs well (218K miles, all original engine & tranny), but recently it has been overheating only when going uphill, such as this weekend heading up a dirt road to a campground. Temp gauge goes to the L in NORMAL, comes down to the low end of the range when I head downhill. I have a new thermostat -- will install it ASAP -- and will check the fan clutch as recommended in other forum posts. Also will check for tranny fluid sludge on the a/c condensor as mentioned here also. No coolant loss (system flushed and refilled recently), engine oil clean.

Need advice on this symptom: when the Temp gauge goes to the L in NORMAL or thereabouts, the hydraulic clutch loses power and I can't shift, or it is difficult to shift (5-speed manual). Noted a small amount of fresh clutch fluid sprayed on the firewall near the clutch fluid reservoir, but fluid level normal. Also noticed some black gunk in the clutch fluid reservoir. Shifts fine when engine is cool. Whadya think?

Steve

 

[nitro71]

I think you have two non-related issues. I think you're probably on the right track with the thermostat. Find out how to check the fan clutch to. No water pump weeping fluid I take it? So that's probably good. I take it that you do have a fan shroud also?

I'm wondering how you know the hydraulic clutch loses power? Nothing when you push it down or? My tranny has the hard shifting symptoms. Probably all the same stuff I asked in that thread applies to you.

 

[HadAFalcon]

No fluid leaking from water pump, and yes, I have a fan shroud. When hot, the clutch pedal feels very soft and won't allow a shift at speed or while the rig is stopped, or makes shifting difficult.

Steve

 

[nitro71]

I have a hard time seeing how shifting could be related to your engine temp. There aren't any coolant lines to the tranny.

 

[HadAFalcon]

Still Overheating, Clutch Still Losing It

An update: I've installed a new thermostat, upper & lower radiator hoses, new radiator cap (13 lbs.) and serpentine belt. Flushed cooling system -- no rust or gunk, the old fluid looked OK, but not as bright green as the new. The fan and fan clutch are apparently OK, no play or noise from the water pump.

Have taken two trips in the last month, during heat waves -- temps in the 90s and 100s. On long hills, the temp gauge goes to A or L in NORMAL, then retreats to N or O on the downhill side. On long flats, it stays in the R to M range. No loss of coolant, except a few tablespoons burped out when the coolant boiled over into the reservoir. The boiling happened twice -- usually it does not boil.

When the temp gauge goes to A or L, the hydraulic clutch (5-speed manual) goes soft and I can't shift into 1st or 2nd, or it is difficult shifting between higher gears at any speed. This happens only when the engine is very hot. In one instance, I found a bit of clutch fluid that looked to have sprayed or spurted onto the firewall from the fluid reservoir. I topped it up. The clutch works fine when the engine is cool.

So, I'm still mystified by the overheating. The engine (4-liter V6 with 220K miles) runs smooth, has plenty of power, burns no oil, and gets ~21 MPG. Suggestions? Bad plugs? Bad karma?

Steve

 

[doonze]

I had an overheating issue awhile back, you can read the thread in my signature if you feel it could be in any way a slightly clogged radiator. Since your having an issue if it was me I'd at least flush it once with the Super Radiator Cleaner, and get a $3.99 back flush kit and use that too. Mainly I point to this because it's a cheap process and can't hurt anything, only make it better or do nothing at all.

So anyway, when I was overheating (beyond L sometimes) I never had an issue with my clutch or 5 speed at all. Somehow I think either it's getting way hotter then it's really showing and somehow transferring that heat over to the clutch fluid, or somehow it's making that tranny really hot and that's transferring the heat to the clutch fluid.

Very weird issue. I would attack the overheating issue first, and if you get that tackled and the clutch thing never comes back I'd just write if off as a issue and call it good.

I would think your overheating is either:

A) Not moving fluid like it should, this would be a radiator or pump issue mostly. Small possibility it could be clogged water channels in the block too. Maybe even a clogged heater core.

B) Clutch fan. I'm not convinced the test you can do really tell you anything 100%. I think if it's 100% shot, the test will tell you so, but if it's say 90% shot, they don't tell you much. So, for the price of around $50-80 (for a super duty clutch), and the labor involved I'd say it'd be worth it to give it a try. From what I've heard ALL of these clutches WILL fail to work right. So no matter what they WILL have to be replaced sometime (Maniak has stated he's heard it's as much as 10% per year decrease in clutch performance. So that means replace at least every 10 years to stay on top). Might as well do it. Once again, can't hurt and can only help. Plus I think the "heavy duty" clutches might be a little bit better then stock anyway, so might not be a bad idea even with a stock clutch that's working decent, like mine. I don't overheat anymore, but on hills I rise a letter, and I can't sit in a drive through for 10 minutes without it getting up around M.

Math Edit:
I don't think the 10% rule means at 10 years your fan is at 0%, I think you LOSE 10% each year...so....
Year:
1 100%
2 90%
3 81%
4 72.9%
5 65.6%
6 58.9%
7 53%
8 47.7%
9 42.9%
10 38.6%
11 34.7%
12 31.2%
13 28.1%
14 25.35
15 22.8%
16 20.5%
17 18%

So, if this is close to being true, most of us are around 20% performance on our stock fans. Only on hills, really hot places (like AZ), towing, etc. do we notice. Other times's that 20% is still enough to do fine. I would also say in places like AZ when the fan "runs" more, that it goes out faster. Maybe like 15-20% a year....

I have no research to back this up, just a fact Maniak had heard, and I didn't believe my fan was -60%, so this way of figuring makes MUCH more sense and explains it, it also holds up to the evidence seen by board members post I've read about this issue.

Anyway, that's how I could see it, and it makes sense...

 

[burgundy1994xlt]

Change the temperature sender to be sure that isn't part of your problem. Was mine after a radiator swap and I had broken the tip the connector goes onto. The original was shot come to find out. For 5 bucks or so thats one thing out of the way.

Single tip unit on the top, left front with the L shaped connector. Real lovely to swap out if the wiring harness and some other lines are in the way like on mine.

http://media.photobucket.com/image/ford explorer temperature sender/webmastercharlie/IMG_0787.jpg