Well i started my car this afternoon and the temperature gauge, within five minutes, went from cold to way past hot. I know the gauge is not accurate because and engine that hot would not be able to be touched, the radiator hoses were still cold, the valve covers cold as well. I could drive a car around with no coolant and it wouldn't overheat like that in five minutes, its about 40 degrees outside.
I tested the sending unit, I get values between 84 Ohms and 18 Ohms which seems normal. The car is an 88 with an 87 5.0 and an buttstuffog cluster. I used the temp sender out of my 88 v6 because it screwed right it. It was worked fine for about 2-3 weeks, ever since I first started the car. Could the sending unit be bad even though the readings are within range? I swapped out the cluster to check for bad gauge and it did the same thing.
Any thoughts?
If the IVR were acting up, the fuel gauge should go up at the same time.
The lower the resistance of the temp sender the higher the gauge will read.
If you pull the wire off the sender does the gauge go back down?
By the way. IF you drove it without any coolant it wouldn't register as hot. It would show dead cold, cause it reads WATER TEMP. No water. No temp. So you would burn up the motor while you thought it was cold.
yes if i pull the wire the gauge goes back down.
Sounds like it has to be:
1. The sender is bad.
2. It's the wrong sender.
3. It's getting too hot just in the area of the sender.
This seems to be the same time your gas gauge stopped working too, isn't it?
pretty much yes. The temp worked for a ocuple of weeks, seemed to be fine. It read about half way everytime it warmed up. I bought a new temp sending unit to try that.
Alright I changed the sending unit for the temp and It ran for 20 minutes, and I took it up the street and back. It seems alright. It seems to teeter around 3/4. I guess thats okay. I'm just used to my 3.8 which never got hotter than about halfway except if it was low on antifreeze.
My old '88 Blue Max had a temp gauge that would instantly go all the way up to H when the thermostat opened. I changed thermostats a few times, the gauge sending unit 3 times, and tried 3 different instrument clusters. Still did it every time. I don't know if it was in the wiring, or what, but nothing solved the problem. So I sold the car LOL.
I know this sounds strange but...try disconnecting the battery for about an hour, then reconnect and see if that helps with the gauge.
dude, you got electrical issues out the wazoo.
im tempted to sort all posts by you and run through a few pots of coffee and figure this mess out. you lucky you dont live near me cause all this would bug the bajezzes out of me.
im starting to think you need to change the ivr and start from there. the resistance of the senders are all in my diy link if you got time to check it out.
alright i will thanks. The only reason im not thinking its the ivr is i have a second cluster, and if i plug it in i get the same things happening. I doubt both clusters are bad. This seems to have worked just by changing the sending unit. We'll see.
Never rule out the possibility of another bad part
When I had my computer shop, I saw tons of bad parts. A lot of them were still in the package when I installed them.
long story short.... assume everything is bad unless you prove it otherwise.
That is a good point. but at the moment everything seems to be working again. The gauge doesn't seem to go part 3/4 now. Its really cold outside for the thermostat is not going to open and stay open, and with all the things taken apart and or not back on yet,(ie hood leaky heater core etc.) I'm not going to drive around for a long trip, not yet.
If it does go up use a temp gun on the themostat housing and hoses to rule overheat out.
I dont think the car is close to overheating. When the car was driven here it seemed to stay normal. I've done up the street a few times and it seems to stay in norm, just at the very top of the "norm".
For you guys with v8's where are your temperature gauges when they are warmed up?
my after market reads 190 I have 180 thermostat and a electric fan on low.my digital gauge only goes about a 1/4 up the scale. thats in summer on hot day.
The gauge in my 5.0 bird runs at the 1/2 way mark. had it running yesterday. (idling)
I had a E-250 with a 5.0 that always ran at the edge of hot all it's life. Didn't matter what the temp out side was.
hmmm. Interesting.
On my 5.0 bird the temp gauge is normally right above 1/2 way mark on long distances (over an hour) and short runs (45 mins or so) just below.
alright, mine seems to run about 3/4 maybe a little bit more.