My '97 F-150 with the 4.2L V6 started giving problems last week. After driving for about 20 min. or so to get the engine warmed up, I notice that temperature needle (the one that has never moved) starts climbing. On the highway it'll stay cool enough, but once in traffic or on city streets, it heads straight for the red zone. Putting the heat on cools it down. Took it to one dealer...they couldn't duplicate it or find anything wrong with the cooling system. They changed out the thermostat...didn't help. I'm off to another dealer today. Any suggestions?

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Bright Red '97 XLT, 2wd, 4.2L V6 with 85K miles, 5sp, SB, SuperCab, Norfalk Plant, DP Box, Duraliner, K&N Filter, P245/70R16 Michellin LTX, and other odds & ends

 

Water pump starting to go out? Cant say w/o seeing it, but somewhere to look. Is it holding fluid?

 

When the needle rises off that 'rest zone', you should her the fan working like it's trying to pull the truck -- if not, you've found your problem.

Check for oily film in your antifreeze; and check for 'milk' in your oil -- either of which often means a head-gasket.

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Y2K™

Toreador Red, Keyless XLT SC SB 5.4L E4x4 4wDisc/ABS, 3.73LS, Skid, HD 7700# Towing, LT-245's on Chrome, Tube-Steps, Captain's, 6CD, Tonneau, named: "Nick"

 

Found my repair manual for you, maybe itll help. Straight from the troubleshooting section:

1. Insuficient coolant
2. Drivebelt defective or not adjusted properly
3. Radiator core blocked or grill dirty and restricted
4. Thermostat faulty
5. Cooling fan not functioning properly
6. Expansion tank cap not maintaining pressure
7. Defective water pump
8.Improper grade of engine oil
9. Inaccurate temp gauge

Maybe this will help as you may be able to eliminate many of these(eg-engine oil grade, thermostat) and find a few areas to investigate.

 

Well...
I had one dealer in NJ replace the thermostat...that didn't do it. Next, I drove it home to CT (barely making it through traffic) and brought it to my local dealer. They determined the fan clutch was bad (the other dealer said it was fine). Replaced the fan clutch and guess what...I drove it home from work and the needle went hot again.

By now, every facet of the cooling system has been checked out. The truck doesn't overheat initially, it takes about 15-30 minutes to get it good and hot, either on the highway at 70 miles per hour (gets really hot climbing hills) or simply by letting it idle. Once it's hot, if you consistantly pull the hills, it'll go right into the red zone.

There concentrating on heads and/or head gaskets now. Thank god I bought that ESP. Although it hasn't covered every hour of diagnosis time! It's an after market warranty. They gave the dealer 30 min of time to diagnose the fan clutch and 60 min to fix it. It took them 2 hours to find the problem. Guess who picks up the difference!

Any suggestions? Do you agree with checking out the heads?

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Bright Red '97 XLT, 2wd, 4.2L V6 with 85K miles, 5sp, SB, SuperCab, Norfalk Plant, DP Box, Duraliner, K&N Filter, P245/70R16 Michellin LTX, and other odds & ends

 

Is it cured yet?
If not, are you losing coolant? look for bubbles in the top up tank when hot. this means blown head gasket.
Fight the cost of diagnostics, thats why its at a "factory" trained shop. You should not have to pay for guess work.

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97, 4.6, 3.55LS, Dk red 265/75/16, Leer cap, Rhino bed, rose wood dash kit, CD player, High performance cross drilled rotors

 

Thanks for all your input!!
I went down to the dealer today and found my engine completely ripped apart...this is what they found...
There's a white gunk all in the areas where the water runs through. They figure it was obstructing flow, and think it may have come from some kind of a stop-leak type product? I've never added anything, but, I did buy it used. They also sent the heads to be pressure tested for cracks, and to be flushed. And they're flushing out the entire system.
I'll keep you updated. I hear what you're saying about diagnosis charges...but, how can I argure...this seems to be a hard problem to find, and I'm no mechanic!



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Bright Red '97 XLT, 2wd, 4.2L V6 with 85K miles, 5sp, SB, SuperCab, Norfalk Plant, DP Box, Duraliner, K&N Filter, P245/70R16 Michellin LTX, and other odds & ends

 

Never had any problems but never let a delaer touch it until he/she rides with you and experiences the problem first hand. Otherwise their guess is about as good as ours.

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'97 F-150 XLT Expidition front end (no idea why). 17inch 4x4 wheels with 32 inch tires flowmasters with tips, K&N filter, 5-spd, 4.2 V-6 bedliner, bright clearcoat red, stepside, hidden hitch, 3.55 gear ratio, tinted windows and a BIG reg ford sticker on the back window (my greatest joy is cutting people off who have calvin pissin on the ford sign and they HAVE to look at my big red sticker)