HWYStar
Forum Newbie
Posts: 19
Loc: Philly Area
Reg: 04-09-10
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05-10-11 05:27 AM - Post#2088159
My 1995 Z28 LT1 motor is overheating. I found that my fans are not coming on. This is a new issue that occurred only a few weeks ago. I have checked the fans themselves by touching the terminals to the battery and they do turn but will not come on when the engine gets hot. I already replaced the 3 cooling system relays and tested all the fuses, all are OK and getting power. I'm stumped. Any help would be appreciated.
HellRaiser Johnny
1973 Nova Custom - Numbers matching SBC 350\TH350
1995 Camaro Z28 - LT1\4L60 4 SP-Auto
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Randy_W
None
Posts: 27804
Reg: 01-06-02
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05-10-11 06:23 AM - Post#2088170
In response to HWYStar
See if they come on or at least one does, if the ac is turned on, if so, bad temp sensor.
Randy
DON'T mess with Old Men, we didn't get old by being, STUPID!!!
"The veneer of civilization is very thin!" (Arlo) |
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HWYStar
Forum Newbie
Posts: 19
Loc: Philly Area
Reg: 04-09-10
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05-10-11 07:54 AM - Post#2088201
In response to Randy_W
I looked at the temp sensor on the water pump and it does look like it was replaced recently (I purchased the car 6 months ago)I think there is another on the drivers side cylinder head? Are there any others?
HellRaiser Johnny
1973 Nova Custom - Numbers matching SBC 350\TH350
1995 Camaro Z28 - LT1\4L60 4 SP-Auto
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Randy_W
None
Posts: 27804
Reg: 01-06-02
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05-10-11 09:32 AM - Post#2088228
In response to HWYStar
I had a '95 but I don't remember whee they are, sorry. Just google the year and motor should find the whole sensor layout.
Randy
DON'T mess with Old Men, we didn't get old by being, STUPID!!!
"The veneer of civilization is very thin!" (Arlo) |
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fbi9c1
Frequent Contributor
Posts: 1658
Loc: Los Angeles
Reg: 08-07-07
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05-10-11 11:41 AM - Post#2088268
In response to HWYStar
The the PCM gets its fan turn on info from the sensor on the front by the water pump. The gauge gets its information from the rear one.
To test:
pull the pigtail to the front sensor, one fan should come on in a few seconds followed by the other one a few seconds later. If that happens, there is nothing wrong with that system or the fans. If one or both do not, check the fan relays and make sure there is no corrosion around the pins.
If the relays are blowing, it is a sign that one or both of the fan motors are getting weak. Visually it is hard to tell if they are getting weak because they are still running, just not fast enough.
Also, turn on the A/C. The primary fan should come on.
If the system checks out OK, start looking at the thermostat. Be sure to use an LT-1 specific one for the reverse-flow cooling system.
Next, pressure test the system and look at the pressure cap.
Good luck.
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Cool81Z28
Forum Newbie
Posts: 43
Age: 45
Loc: St. Petersburg, Florida
Reg: 12-10-09
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05-10-11 12:13 PM - Post#2088273
In response to fbi9c1
Here is a sight with alot of good information.
cooling system
1981 Z28
1994 Camaro
1965 Pontiac Lemans |
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HWYStar
Forum Newbie
Posts: 19
Loc: Philly Area
Reg: 04-09-10
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05-11-11 04:32 AM - Post#2088512
In response to HWYStar
Thank you all for the information, I will run some of the tests suggested later today.
Yesterday I had tested running the A\C after pulling off the highway (which is when I normaly would overheat) and the temp stayed just above the 180 mark which is normal, so this tells me at least one of the fans is running.
It is starting to look more like a Temp Sensor so I will most likely get on that next.
Again - Thank you ALL for the help, I do appeciate having a place to go for help with vehicle(s). I'll follow up when I have this beat.
JP
HellRaiser Johnny
1973 Nova Custom - Numbers matching SBC 350\TH350
1995 Camaro Z28 - LT1\4L60 4 SP-Auto
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