Question on Engine Temp

[chesnut]

Question - what is normal engine temp behavior in Texas summer weather 100 degree plus temperature?

My 1992 runs cool - 180 or less at highway speeds. During in city driving in the Texas summer heat 100 plus temps, the temp gauge will get close to the danger zone.

Same if weather cooler and driving hard like on a road course such as NCM Motorsports track.

Replaced both fan relays.

Car has never overheated.

Appreciate y'all's help. Thanks,

Gary
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[Dynomite]

Post 7 - Thermostats, Fans, Water Pump, and Radiators (http://forums.corvetteforum.com/c4-zr-1-discussion/3005470-tech-info-lt5-modifications-rebuild-tricks-500-hp.html#post1580070558)

[Chuck Banks]

I?m not in Texas, but frequently see 95* here in Prescott AZ @ 5200? elevation. City traffic with AC running engine temp will rise to about 221* before fans must kick in and bring temp down to about 207. Mountain driving shows the same high temp before slowly coming back down. I?ve never seen a temp above 223* so nowhere near the shaded zone on the analog gauge. I?m at 101500 miles with original radiator, but have thought about pulling it to see if debris has built up between the condenser and radiator.

Chuck

[Mikey]

Make sure your water level is full. My car has a leak in the recovery tank and I know water is low when I start seeing temps on the rise.

[WARP TEN]

I believe that when Marc Haibeck does a chip for a ZR-1 he sets the fans to turn on at 205 degrees. --Bob

[chesnut]

Dynomite,

GRRRREAT read - appreciate the link(s). Many thanks,

Gary
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[Young1]

Yes make sure black tank is full and white tank a 1/2 inch above line. Replace radiator cap if it is 30 years old. After a plenum pull recently I filled it and then noticed temps higher than normal. It was down 2-3 pints.

Yes you must pull radiator every 50,000 miles to clean it. Here in FL sand jams in the fins from following other cars too closely. It is surprising how much it scoops up.

[Hobbes]

I don?t remember the exact numbers, but last year I was pegging the temp gauge during the Houston heat of June/July. I ended up pulling the radiator for a good cleaning, put in Marc?s thermostat & chip, flushed the entire coolant system, and refilled with green coolant. Both the analog and digital temp gauge have been solid in the safe zone since then, even with long drives in 100+ degree heat.

[chesnut]

Temp update

June driving on I45 stop'n'go traffic in Houston area - '92 turned off the A/C and regular temp gauge was in the "danger zone".

Since then:
1) installed Marc's chip to turn on fans at 205
2) replaced radiator with 2 row DeWitt's radiator

Short test drive this morning went well. Ambient temp was 88 degrees.
- Idled with A/C on while filing up with gas & temp got up to 230
- Drove back home
- Idle for 15 minutes in driveway with A/C on and temp digital gauge showed 240

Checked top of radiator with temp gun and it showed 140 degrees.

Is there an easy way to tell if the passenger side radiator fan is on? I'm having a hard to seeing the fan blades to tell if they're moving or not.

Thanks,

Gary
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[Young1]

Tape some thick paper to end of something and slide it down there slowly. Like clothes pinning a baseball card to make noise on bicycle spokes when I was a kid. Or was I the only one that did that?

[chesnut]

Young1,

Thanks, will give the ye ole bicycle card a try.

Gary
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[HAWAIIZR-1]

Temp update

June driving on I45 stop'n'go traffic in Houston area - '92 turned off the A/C and regular temp gauge was in the "danger zone".

Since then:
1) installed Marc's chip to turn on fans at 205
2) replaced radiator with 2 row DeWitt's radiator

Short test drive this morning went well. Ambient temp was 88 degrees.
- Idled with A/C on while filing up with gas & temp got up to 230
- Drove back home
- Idle for 15 minutes in driveway with A/C on and temp digital gauge showed 240

Checked top of radiator with temp gun and it showed 140 degrees.

Is there an easy way to tell if the passenger side radiator fan is on? I'm having a hard to seeing the fan blades to tell if they're moving or not.

Thanks,

Gary
....:flag:

What about if you keep your AC off then does your fans work and temps stays
down? If so, you have same issue as I do with AC pressure switch or high pressure.

https://www.zr1.net/forum/showthread.php?t=33274

[chesnut]

HawaiiZR-1

Please elaborate on your "AC pressure switch or high pressure" - am not familiar with this problem.

Thanks,

Gary
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[chesnut]

Young1,

Didn't need to do the bicycle card trick to see if the passenger side fan was running.

Pulled into the garage out of the sunlight and could see the passenger side working with a high powered flashlight.

Thanks,

Gary
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[chesnut]

HawaiiZR-1,

Early thought the A/C wasn't working correctly. The Tech checked both hi & low side and they have proper pressure.

Problem was bringing in the outside air. Tech recommended set to recycle air and all is good with 44 degree vent temp with 100 degrees Texas temp.

Did learn one thing when I attempted to put my gauges on the high side. Bought a Santech R12 high pressure port adapter for GM Deep Access 1991 & later part no.: MT0436

Thanks,

Gary
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[DRM500RUBYZR-1]

Buy an inexpensive Coolant Pressure Tester.
Check to see if it hits and holds approx. 14-15 pounds.
My car ALWAYS ran cool until it did not.
A very hot day car show procession up to and on the boardwalk at OC NJ and out of nowhere, I was suddenly at the danger zone and moving beyond.........

Radiator Cap was fine, but I had the smallest of leaks on the upper connection of the lower hose. Never left a drop underneath the car, ( must have evaporated near immediately ), but enough to keep the system from pressurizing.

All was fine (170-190) until stressed, then quickly out of control.

Once found, 1 minute to tighten the clamp and all was well again.

That $20.00 tester could save you hours of expensive diagnosis time at any shop.

Keep us posted of your findings or lack thereof.

:cheers:
Marty

[chesnut]

DRM500RUBYZR-1,

Appreciate your good suggestion about the coolant pressure tester.

Did the pressure test after installing new radiator earlier this month. Also replaced the pressure cap as a precaution and also tested it.

Out of caution, I recheck the clamps for tightness every time I take off on a Road Tour.

Was interesting for me to read that Chevrolet engineered C4's to run 220+ to help pass EPA standards. And used the same radiator through the C4 Corvette run without any regards to HP.

My '92 runs good temps around 200~212 with normal highway driving, even in hot Texas summer 105 degree temps, with A/C on as long as i keep the car moving. It's the stop'n'go traffic that I get stuck in, that causes the temp to creep up to around 240. Never had a Corvette run that hot before, ever. It's never puked. But this June it did shut off the A/C, which was a first.

Fixin' to head out on the NCRS Convention Road Tour. Installed new 2 row DeWitt radiator, Marc Heibeck's 170 degree thermostat and chip.

Thanks again for sharing.

Gary
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[chesnut]

Status report after driving 3,124 miles on the NCRS Convention Texas Road Tour to Hampton Roads, VA.

Before the trip upgraded the cooling system with a new DeWitts 2 row, new thermostat, Marc Heibeck's throttle body bypass tube & chip. Also, installed a debris screen.

When I removed the upper radiator shroud, found all kinds of trash on the radiator, etc. including a page from a porno magazine 2002 printing.

Trip to Hampton Roads - Engine temp was running 200 to 230 depending upon the gear and traffic. Stop'n'go traffic in 100 degree heat drove temp over 240 and to 250.

Air cleaner on car is the aftermarket Automotive Performance Intl. from Seattle, WA with the big scoop in front of the condenser and radiator.

In Ashville, NC decided to remove the scoop. Stopped by Harbor Freight and bought a compass hand saw. Roughly cut the scoop off of the air cleaner.

Return home trip with outside temp 95 to 100 degrees - cooling was improved 190 to 200 degrees at 70~75 mph in 5th & 6th gear. 50~60 mph in 4th gear up to 210 degrees. Stop'n'go traffic for over 30 minutes, engine temp never got about 235 degrees.

Every evening during the trip, cleaned road trash off of the debris screen, which before would've been sucked into the radiator.

Duh, never dawned on me the air cleaner's big scoop was restricting air flow to the condenser/radiator.

Appreciate everyone's help and advice.

Gary
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