temperature fluctuating
Posting Guru
Joined: Jun 2004
Posts: 1,781
Likes: 1
From: Central NY
I don't have this pronblem on my truck, but I used to have a car that would do this a few times a year and the fix was to turn the timing back to spec.
Hmmm.. funny but now that I think about it, that car was a Ford too! LOL
Popa Tim
Hmmm.. funny but now that I think about it, that car was a Ford too! LOL
Popa Tim
Senior User
Joined: Sep 2004
Posts: 391
Likes: 0
From: brooksville, florida
On older cars there used to be a voltage stabilizer that kept all the gauges working correctly, I dont know if 1990 or later models have this item, maybe ford mechanic knows, I know on an old car I had this item went bad a caused the gauges to fluctuate.
Thread Starter
|
New User
Joined: Nov 2004
Posts: 23
Likes: 0
well i looked into the voltage regulator for the gauge even though i know the actual temp is fluctuating. the 95 f150 does not have one in it. the only voltage regulator is in the alternator. went to autozone, had them test it in the truck then pulled it out and had them test it on the bench. both times passed no problem.
now the confusing part. drove the truck 35 miles this morning, did not fluctuate. half way home, it started to fluctuate again and has all afternoon up till now. any thoughts on why the temp fix?
thank you. you guys are great.
now the confusing part. drove the truck 35 miles this morning, did not fluctuate. half way home, it started to fluctuate again and has all afternoon up till now. any thoughts on why the temp fix?
thank you. you guys are great.
Posting Guru
Joined: Nov 2003
Posts: 1,071
Likes: 1
From: Concord, New Hampshire
Did you check hoses?? i mentioned it before, and it is something that would cause your situation. they would only collapse when the pump is turning faster, causing more circulation.
Thread Starter
|
New User
Joined: Nov 2004
Posts: 23
Likes: 0
the hoses seemed pretty firm when i removed them to replace the rad. and water pump. i do not think the lower hose has a metal spring in it and i know the upper does not. could i get the truck warm and rev it to see if the hose collapse or does the amount of load on the engine effect the hoses collapse?
thank guys for all of the help.
thank guys for all of the help.
Posting Guru
Joined: Nov 2003
Posts: 1,071
Likes: 1
From: Concord, New Hampshire
FTE Stories
Ford Trucks for Ford Truck Enthusiasts
10 Best Ford Truck Engines We Miss the Most!
Joe Kucinski
2026 Shelby F-150 Off-Road: Better Than a Raptor R?
Brett Foote
2027 Super Duty Carhartt Package First Look: 12 Things You NEED to Know!
Michael S. Palmer
10 Most Surprising 2026 Ford Truck Features!
Joe Kucinski
Top 10 Ford Trucks Coming to Mecum Indy 2026
Brett Foote
5 Best / 5 Worst Ford Truck Wheels of All Time
Joe Kucinski
Ford Super Duty: 5 Things Owners LOVE, 5 Things They LOATHE!
Joe Kucinski
Every 2026 Ford Truck Engine RANKED from WORST to FIRST!
Michael S. Palmer
The Best F-150 Deal of Every Trim Level (XL through Raptor)
Joe Kucinski
Senior User
Joined: Sep 2004
Posts: 391
Likes: 0
From: brooksville, florida
now this is strange because the top hose on my 1991 f150 5.0 collapses after it has been run and turned off, then expands again when started up from cold but I don't have any trouble with the gauges, I think it must be pulling a vacuum in the system when shut down, but has not yet caused any problems and runs fine otherwise.
Thread Starter
|
New User
Joined: Nov 2004
Posts: 23
Likes: 0
cbr, sounds to me from what i know that the overflow tube is kinked or blocked up or the cap is not working properly. when the coolant heats up, it expands, once it builds up enough pressure, the cep sends some coolant to the overflow tank. when the system cools, the coolant "contracts" and it sucks back coolant from the overflow to replace the coolant that was sent to the overflow tank. id check the rad cap and the over flow tube.
ill try reving up the motor when it is hot and see if the bottum hose collapses or not.
thanks again for all of the help.
ill try reving up the motor when it is hot and see if the bottum hose collapses or not.
thanks again for all of the help.
Posting Guru
Joined: Nov 2003
Posts: 1,071
Likes: 1
From: Concord, New Hampshire
it amy be just like someone said and you may have a head gaskey on the worng side, however the head gaskets dont care what side there on, someone above stated they did, but i know with my 5.8 it wouldent take much at all to plug a passage at the head gasket, there only maby 1/4 inch hole if that, id defidently flush it my self or bring it somewhere like jiffy luber or something and have it done.
Thread Starter
|
New User
Joined: Nov 2004
Posts: 23
Likes: 0
i dont think it is the head gasket because ive had the truck for 40k miles and it has never done this before. also this afternoon, on the way home i stopped by autozone and pressure tested the cooling system and cap. cap opend right up at 13lbs and the system held 14lbs for about 4 mins till i took it off. i thought if the cooling system held pressure, the head gaskets were good.
i did notice when i installed the old temp sensor, the gauge hangs a little liower, near the "N" in normal and still fluctuates, but it is not as much on the gauge. however, i think it is just the difference between the new and old(partially broken) temp sending unit.
thanks again for all of the help, i cant wait to get to the bottum of this.
i did notice when i installed the old temp sensor, the gauge hangs a little liower, near the "N" in normal and still fluctuates, but it is not as much on the gauge. however, i think it is just the difference between the new and old(partially broken) temp sending unit.
thanks again for all of the help, i cant wait to get to the bottum of this.
Freshman User
Joined: Oct 2001
Posts: 42
Likes: 0
From: ohio
Check all your engine/battery grounds that go to the body in the engine compartment. There may be as many as 4 ground straps in the engine compartment. Since you indicate other cluster problems it most likely is a ground problem. If that does not sure your problem It may be in the cluster as the cluster has diodes and most likely a voltage reducer built into it. Check e-bay as i have seen dash clusters there very reasonable. You can put your speedo into the other cluster if the milage is off a great percentage on the replacement cluster.--PS--CHANGE ALL THE HOSES you may have an internal collapse even if you do not see it from the outside. I have delt with these problems before.
Last edited by buzzer; Dec 20, 2004 at 02:31 AM. Reason: adding info
Thread
Thread Starter
Forum
Replies
Last Post
pizzadahutt
1983 - 2012 Ranger & B-Series
9
Jan 5, 2011 06:20 PM