My cousin's 96 Mustang GT overheated because of faulty thermostat/ECT sensor. Costed him mucho dinero$.

My wife's 98 V70 started acting up (running hot although not to the point of overheating - I addressed the problem as soon as perceived) because of the same related issue (faulty ECT sensor, replaced it as well as the thermostat since its inexpensive and in the way).

I guess my question is, if it is a good thing to replace the hoses around 100k as suggested by a gentleman here, would it be a good idea to replace the thermostat and ECT sensor at the same time too instead of waiting for it to fail?

All of the above - hose, thermostat, and ECT sensor would require draining of coolant, and this being fall (well, almost) and folks winterizing their rides and some probably scheduled for coolant flush, and most 1st Gen XP's are probably in the 100k miles mark at this point, I thouhgt I throw in this idea.

Thoughts?

Orlee

 

yes you could do all of that. but use the best quality thermostat possible not the crap ones from a parts store. and make sure to use the right coolant. if that coolant is yellow you can only use zerex.

 

Thanks, mine use green stuff, and will probably stick with MC brand, if available at dealership just to be sure.

OEM Thermostat & ECT sensor run to about $30 at fordpartscheap.com, a good preventive measure I believe.

Anybody have any idea why lower hose is so expensive, compared to upper hose?

 

I would not worry about the ECT sensor as this does not control coolant flow only tells the computer the temp so that the air fuel ratio can be fine tuned. Don't worry about an excessive lean condition from this as the computer will stop listening to the sensor before this condition can occur. As for the thermostat there is a newer style not sure of the maker that fails open. Also check your fluid clutch for the fan. These only last about 50k, if you need to know how to check it let us know. Good Luck.

Dave

 

becasue the lower hose is sooooo long.

 

Are you referring to the silicone fluid for the clutch when you said it lasts for 50k or the clutch itself? Any tip on how to check the fluid, and possible how to 'lube' the unit is welcome as Haynes does not give that detail.

Also, Ford (Expedition specifically) may operate differently as far as ECT is concern, but it's not possible lean condition I'm concerned about, it's possible rich condition when the ECU tires to compensate when ECT sensor is not functioning properly, which I believe is what happened to my wife's car. Prolonged rich condition is not good to CAT converter among other things as you know. I cannot explain why but my wifes car, when running rich (without any CEL triggered) was running hot, with unmistakable oil-burning smell, and the gas mileage went down considerably. I did a little digging on another forum for her car and possible malfunctioning ECT sensor caught my attention. Sure enough, when I replaced it (along with the thermosts which physically is not damaged, at least not visibly), the running hot condition went away. The mileage improved some but not on the normal level, so I went ahead and 'cleaned' the O2 sensors, which is all white, a sure sign of rich condition. I'm yet to observe the mileage, but the performance is much improved.

If I'm not accurate on this, or somehow, this does not apply to Expedition, I would at least feel better thinking that my Thermostat and ECU sensor is good for another 93k, since cost is ony about $30 for both unshipped, and these are 'good' things one can do while the coolant is drained. Just my 2 cents of course.

Thanks

 

Good point on the Rich condition and trashing the Cats. As for the Fan Clutch, the Expy is a sealed throw away unit. As far as checking it there is no perfect way it is more a judgement call. Some things to look for: When you first start the truck tap the gas you should hear the fan roar if the truck has been sitting since all the fluid is in the bottom of the clutch and takes a few seconds to redistrubute. Also if it is warm out get the truck hot like after a work commute and turn all available AC to Max and let the truck sit, this will heat the fan clutch up nicely from the hot condensor air from the AC, now drive the truck the fan should be screaming. Lastly after this stop and shut it off and spin fan by hand it should have a ton of drag on it. One last method it to get a optical tach like model airplane guys use. You sound like you already know alot about mechanics so sorry for the long post but hopefully it will help someone else who searches on the subject.

Dave

 

I just use a whole bottle of royal purple purple ice (about 20 oz.) and the rest distilled water for my coolant. works great and runs a bit cooler.

 

Thanks for the tip guys. I'll keep everything in mind when I flush my coolant before winter.

 

I'm getting ready to flush my coolant, and as planned, ordered from the dealer the thermostat and the ECT sensor - apparently, there are two different kind, one is a round connecter with round pins, but mine happen to use the square connector with flat pins. The thermostat is $11.72, gasket is $7.04 and the ect sensor is $29.04 which is close to Fordpartscheap.com prices when shipping is considered. Also, per Haynes instructions, look like my ECT sensor is not working, the resistance is stuck to only about 300 ohms, both for hot and cold (measured while installed). I understand that the resistance should be around 50k ohms when cold and should read around 1.5k ohms when hot. Funny but no codes are being set. I will try to measure again once its out. I will post again about the matter when I'm done and report any difference in performance / mpg improvement if any, maybe somebody could use the info.

OrleeC