wtf is going on with my 86

[carbed87]

ok so whenever my car is just driving around town the temp gauge almost gets pegged after a few miles of stop lights and what have you. but when i get on the highway, it seems to stay around midway. i thought it was the fan clutch at first, so i swiched the one out for one off my old 91 gt (with 170,000), it didn't seem to help however, i wouldn't doubt that that one is worn out too. anyways, im torn between a few things here. i wan't to test the coolant pressure tomorrow before i buy anything, but it was also brung to my attention that my gauge cluster could be acting funky. the previous owner said that every now and then some of the gauges would peg out, then later return to normal. and while i did see the temp needle do that once (not to mention $20 of gas giving it a full tank lol) i dont know if it would be reading wrong almost all the time. i popped the hood every now and then to find nothing out of the ordinary, no wierd smells, no somke or anything... so im really left out on my own on this one.

any help would be great guys.

thanks,
mike

 

[z2o_what]

i'd try another fan, check coolant, and get an aftermarket temp guage.

 

[carbed87]

im not rockin one of those lame redneck temp gauges, but i will check my fan...

 

[Dean85GT]

mine does that when I turn the lights on. The temp gauge and gas gauge rises right up

 

[nidyanazo]

im not rockin one of those lame redneck temp gauges, but i will check my fan...

One of theose lame gauges will tell you the tempature of your engine, not some arbitrary scale with no known values like the stock gauge.

 

[RsStanG1987]

On an 86 you can get an aftermarket Guage to fit in the stock location.

 

[sunil6784]

How's the coolant level ? I'd pressure test your radiator. Autozone rents a pressure tester for free. Could be that you are losing some coolant. But on the highway the air is cooling the radiator enough that you don't notice it.

 

[93 foxbody]

there is a chip or a voltage regulator on the back of the gauge cluster that needs to be replace. that i had to get from the local napa store few years ago

 

[bt15]

It's probably just your dash voltage regulator. They are notoriously weak on 79-86 model cars. Swap out that $20 part and you're probably all set. Good luck.

 

[795.0pacecar]

They are notoriously weak on all fords from the mid 60s to early 90s.

 

[HISSIN50]

One way or another, you will likely want to use an accurate gauge for diagnostics. Whether or not that gauge remains in the car is up to you.


If it happens at idle, you could use a turkey thermometer in the radiator neck, but you will be altering the true dynamic (hood up, system unpressurized, etc).

EDIT: if an aftermarket gauge is redneck to you, what would you call the turkey thermometer in the radiator neck?



Good luck.

 

[carbed87]

They are notoriously weak on all fords from the mid 60s to early 90s.

where exactly are they

 

[carbed87]

One way or another, you will likely want to use an accurate gauge for diagnostics. Whether or not that gauge remains in the car is up to you.


If it happens at idle, you could use a turkey thermometer in the radiator neck, but you will be altering the true dynamic (hood up, system unpressurized, etc).

EDIT: if an aftermarket gauge is redneck to you, what would you call the turkey thermometer in the radiator neck?



Good luck.

lol i dont see aftermarket gauges redneck, i like autometers, and steart werners and what have you, but i don't like those chrome bezeled sunpro gauges that are buy 1 get 1 free at CSK.

anyways, update... i went to a buddies house and pressure tested the system, everything came out good, and it seemed to be the cap that was the culprit. slapped a good one on and it never went beyond the "M".

thanks guys.