Cycling Temperature

[Empty Pockets]

FMNavajo: I'd say that the engine coolant temp is probably not related to the trans. I have a B&M tranny fluid temp gauge in my '94 EB, so I can see that temp and the tranny temp doesn't really fluctuate much at all. Also, I put this gauge in before I considered putting in another cooler and I now see that I don't need the cooler.

martina: I understand that that growling should be normal, I test drove a few similar Explorers before I bought mine & they all seem to sound the same. I put a K&N filter in and I've heard that should make the engine sound louder but all I still hear is the growl that you speak of.

[This message has been edited by Empty Pockets (edited 01-24-2000).]

 

[DrewP]

Guys,

Mine was cycling exactly as you have described and I too tried replacing my radiator cap with no improvment. However, I checked my overflow reservoir after the car had cooled overnight and it was nearly empty. I filled it up the "COLD FILL" line and drove it with no improvment. However, the next morning after it had sat it sucked some coolant back in and now runs a constant temperature. I know this sounds a little lame, but I swear it fixed my cycling temperature problem.

Hope this helps and if it doesn't you won't go broke from trying.

Drew

 

[ex91]

same prob here its a 91 with about 170,000km on it when i got it it just stayed at the N but now it movees all over the place but never to H can some one help me call ford or someone.


ex91 4dr,4x4,4.0L,4speed,4me

 

[Jeff]

I solved my cycling problem a couple of days ago after it worsened with the final straw being no heat. Stant to the rescue. I replaced the thermostat and the radiator cap. 195 degrees and 16 lbs. The engine runs great just like it did before and the high idle associated with the cycling temperature is gone.

BTW, at my local Kragen Auto the Stant catalog says that there is no gasket for my '97 Explorer V-6 but there is one for the V-8. Don't know why they don't make one since you really can't re-use the old one. I tried and it leaked just a wee bit. New one from Ford and the incontinance problem went away.

 

[getweaked]

I 2 am having the same problem with the wacky gauge as raven2 is. I recenly replaced the fan, themostat and water pump in my 91 xlt with 99,000 miles on it and the temp gauge flops up and down between the "o" in Normal and the half way point. The thing that is killing me though is that the heat does not get as hot or blow out as strong as it used to. After driving my coolant resior is empty after filling it with coolant up to the line. I dont get it, is there enough coolant in the system could it be a bad themostat, could the system have air in it and the heater core? Please help cuz its freezen here in Cleveland,Ohio.

 

[Art93]

Have same problem with my 93 Explorer...The temp. cycles between just over 1/2 to 1/4 in under 1 minute. Does this continually. I found 3 Ford Service Bulletins that sound like they might address this problem.
They are #95132, #95185 & #97-18-9. Does anybody know what the details are?
Thanks

 

[ExploreMinnesota]

I've changed my thermostat 5 times since I bought my Explorer in 1990. I now have 144,000 miles on it.

What I've always noticed is a new thermostat is more active than an older one. The new thermostat will cycle from about straight up down to the bottom of the "o" until the engine is good and warm, after which the cycling range is more narrow. If I'm running down the highway and the engine is good and warm, the fluctuation will stop, and the guage will read just a little under the half way point. But when I slow down again the tempriture will fall a little. That's wiith a new thermostat.

As the thermostat ages, the cycling slowly goes away. I will notice it cycle just a couple of times (especially in the winter) for the first 5 or 10 minutes, but that's to be expected.

I'm interested to hear what the TSB's say about this, but I've never cosidered it a problem.

------------------
ExploreMinnesota
91 EB 4x4 Stock

 

[MikeTEC]

Getting ready to do some long distance driving and pulling our trailer. My 93 Explorer, which I bought new, has 115K on it. So I had my Ford dealer install a new Ford 195 degree thermostat, belt, hoses, fan, HD fan clutch and temperature sending unit. Also I had a new two row Modine radiator installed at the same time. It was cheaper than a new Ford radiator and yet looks to be as good if not a better unit. Temperature guage fluctuated at first quite a bit, but seems to be slowly settling down. Mike

 

[lmacmil]

Another data point

The replacement thermostat in my 1996 does the same thing (cycles the gauge constantly between 1/4 and 1/2 of the normal range. Neither of my other cars does this, nor did the OEM thermostat before it stuck open. Doesn't bother me but I may try a new cap to see if it changes anything.

 

[Campo]

I don't have this problem "yet" (knock on wood)
but nobody mentioned resetting the computer... since the T-gauge is electric and controled by the computer and sensors, wouldn't resetting the computer be worth a try?

Just a thought...

 

[MikeTEC]

Good idea. I had not thought of reseting the computer but it is worth a try. I replaced the cap with all the other new parts, so I could not tell if it helped or not. Certainly it is cheap and always a good idea as preventive maitenance. Mike

 

[MikeTEC]

Resetting the computer did not help. Also replaced the radiator cap with a new Stant 13 lb. cap. but no difference. Still have the fluctuation. Understand some folks have switched to a 16 lb. cap which fixed the problem, but I am wondering will this cause undue pressure the system was not designed for and cause a waterpump leak or other gasket leak? Thanks Mike

 

[Bronco_bill]

I am having the same problem but don't feel that a fluctuating gauge is normal new T-stat or not. I rebuilt my engine about a year ago and replaced the stat and everything was fine. My rad begain to leek and I ran hotter than normal but dont think there was any damage. First thing that may help some of you is to make sure that the little brass plug around the rim of the t-stat is directly at the top. This helps air to pass through. I have had the original 13# cap on the truck for 215,000 miles and has worked all that time. I am going to buy both a 13# and 16# and see if either works. everything else but the cap has been replaced in the cooling system but has had no improvement.

 

[MikeTEC]

I noticed sealant around my temperature sending unit when it was installed by the Ford dealer. Is sealant supposed to be used on the threads of the sending unit? If not, could this be contributing to our problem? I can see how the computer might be receiving inaccurate readings caused from the sealant's insulating properties. Mike

 

[Bronco_bill]

I tried both caps and had no improvement. I am going to leave the 13# and make sure there is no air in the syatem 1 more time. I have a manual (don't know i the auto have a tach) I notice a slight dip every once in while. Anyone think if there is a bad wire or plug it will make the temp go up/down if it fires intermitenly?

 

[MikeTEC]

Bill: I think you would be able to tell if a plug or wire were the problem as it would probably miss/lack power or burn a lot of gas. I once read a post somewhere a person found their wire connection to the temperture sending unit was loose/not making good connection and that cured his problem. Mike

 

[Bronco_bill]

Didn't think so but I pulled the plugs anway and they look great. The truck runs excellent but the cycling gauge is really staring to piss me off!

 

[MikeTEC]

Took mine back to the Ford dealership today for another new OE thermostat to be installed. No difference, the thermostat still cycles! (Although not as much at highway speeds.) While there a mechanic mentioned I might need to have the updated waterpump installed, which has a higher volume output to accomodate my new larger HD radiator. He said he thought Ford came out with the larger water pump in 1998. But I am not prepared to go that far with additional expense, so I will just wait until my waterpump wears out and have the updated one installed then. If that does not cure it, the only part left is the temperature guage itself. It sure is a mystery alright. Perhaps a really knowledgeable technician can read our posts and give additional suggestions. Sorry for the long post. Mike

 

[tcbarney]

Bringing this post back from the dead...

Doing a lot of searches to see if there is a definitive answer to this issue. From this and other threads, seems like it could be any of several things:

1. Bad thermostat
2. Air bubble
3. Bad radiator cap
4. Clogged radiator
5. Bad water pump
6. Bad fan clutch
7. Loose wires
8. Head gasket leak
9. ....what else...?

I just noticed mine doing this flucuation recently. Did a 60k service just a couple months ago, where I flushed coolant and changed t-stat and rad cap.

Then, on Thanksgiving, got a chirp when I started the car that my brother said sounded a lot like when his water pump in his SHO started to go bad. And I think I caught a whiff of coolant after I parked the X. Haven't crawled under yet to see if the weep hole is weeping.

So my problem may be a water pump starting to go. I will post after I replace it and let this thread know if it helped the gauge problem. I'll not do the tstat and rad cap again right at first, so I can tell for sure if the H2O pump did the trick.

 

[gooter87]

Hey Guys... same problem.. just put an OEM replacement TStat and it rises and drops... i am now starting the smell that wonderful aroma of antifreeze coming out of the vents.. just did a head job ( had crack in head gasket between cylinders 5 and 6 ) flushed and refilled... what could be the issue? i don't feel any wetness on the carpet on the passenger side...