fluctuating temperature
Senior User
Joined: Jan 2004
Posts: 342
Likes: 0
From: British Columbia
Originally Posted by i1dery
Okay almost back at square 1
it seems it wants to run hot say high side of the m on the highway, then comes back down to the low side of the o doing around 35-40 ???
it seems it wants to run hot say high side of the m on the highway, then comes back down to the low side of the o doing around 35-40 ???
Senior User
Joined: Jan 2004
Posts: 342
Likes: 0
From: British Columbia
Originally Posted by i1dery
A real temp gauge you shove into a turkey? honestly not sure what kind, and could this be due to that the clutch on the fan
is not working properly?
is not working properly?
And I meant a decent aftermarket temperature gauge. You cannot rely on the factory gauge to give an accurate reading.
New User
Joined: Jun 2005
Posts: 1
Likes: 0
Temp Fluctuations
One Thing Everyone Is Overlooking Is A Good Possibility That You Are Getting Small Amount Of Cylinder Exhaust Gas Blow By Between Your Heads And Block....head Gasket/s Could Be Leaking Enough That Wont Cause Any Other Problems For Time Being And That Is More Likely Why You Are Seeing Temp. Fluctuations....small Amounts Of Exhaust Gas Is Probably Getting By Head Gasket And Into The Coolant And When It Gets To The Temp. Sending Unit It Is Seeing That Higher Temp. Thus Causing Fluctuation......want A Peice Of Mind?????? Take A Sample Of Coolant And Have It Annalized....chances Are Thats Your Problem And If Not, Well You Should Sleep Better Knowing The Next Time You Go On A Long Trip Your Not Going To Get Stranded Because Of That............hope This Helped Everyone......aerohead1....
Post Fiend
Joined: Nov 2001
Posts: 14,947
Likes: 6
From: Topsfield, MA
Well, honestly, in my particular case I don't believe that is my problem.
My motor is brand spanking new and the way the temp flucuates doesn't make me believe it's like that. It'll stay around 120 or so and sometimes go up and stay at 190-200 then go all the way back down to 120ish...keeps going up and down randomly. I got some air bubbles out of the coolant last time I took the cap off, and I noticed it stayed at 190-200 more...so maybe if I keep doing that it'll fix my problem. It really sounds like air bubbles to me. Unfortunately, I've been working on other issues so I havn't spent much time trying to fix this, but I will.
My motor is brand spanking new and the way the temp flucuates doesn't make me believe it's like that. It'll stay around 120 or so and sometimes go up and stay at 190-200 then go all the way back down to 120ish...keeps going up and down randomly. I got some air bubbles out of the coolant last time I took the cap off, and I noticed it stayed at 190-200 more...so maybe if I keep doing that it'll fix my problem. It really sounds like air bubbles to me. Unfortunately, I've been working on other issues so I havn't spent much time trying to fix this, but I will.
Senior User
Joined: Apr 2004
Posts: 443
Likes: 1
From: Central Va.
i have a 96 f-150 haveing the same problem,replaced the t-stat 2 and the water pump and the head gaskets,still have the problem with the temp gauge running to the r and the m in normal. i have owened the truck for 8 years and it has always run around the o so ive got a problem somewhere and still looken. also has a new tenp sensor and a radatior 2 yours ago ,i am lost ???????????????????
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New User
Joined: Sep 2008
Posts: 3
Likes: 0
haveing the same problem with my 96 f150 ran alot of test to find out this problem.i pulled the temp sensor (GAUGE) replace it with a new one and had the same problem with the temp running to the m and the r. so i took the old sensor and cleaned it,seems to be the fix.now its running back where it has always have been right on the (o) in normal. will drive it for a couple of daays and see how it does
Der Postmeister
Joined: Sep 2006
Posts: 6,859
Likes: 560
From: Long Beach, Calimexiforia
Gauge Fluctuation is almost always the single wire Water Temp Sender to Gauge Unit itself or the quality of its connection(Not to be confused w/ the ECT Sens/switch). While senders tend to fail with increased increments, Thermostat failures tend to be "all in or all out". The PCM requires a signal by the ECT that 195F coolant temp or more is occuring to permit it to enter or continue closed loop function. Below that the engine remains in "warm up mode purgatory", which is over rich & under advanced = Lackluster performance & poor MPG. Switching to a lower temp thermostat in response to an overheating situation is a short term adaptation to a symptom that allows the cause to continue. Then when the actual cause is rectified the lower temp thermostat will allow coolant temp to fluctuate above and below normal op. temp and simultainiously in and out of closed loop function. Something to remember in the future when experianceing an intermittent
poor drivability problem.
poor drivability problem.
Der Postmeister
Joined: Sep 2006
Posts: 6,859
Likes: 560
From: Long Beach, Calimexiforia
If you decide to use a radiator flush to improve overall coolant sys. function (good choice),there's 10 min. & flush formula, highly aggressive chemically and a much less aggressive formula designed to by added to coolant sys and the vehicle opreated with it the day before the flush. This method yields better results.
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