billschroeder5842

Quick question on the accuracy of the gauges as this ZR1 is new to me and I'm still trying to get the handle of things

I drove home today (72 degrees and 80% humidity) in Dallas stop and go traffic and my temp gauge and oil temp gauge made a notice "jump"

Normally, the temp (If using a clock) is about 2:30 when I'm on the open road at 75-80. Today it went to 3:30 in some stop and go. It was not in the "danger zone", but definitely higher. The auxiliary fan did come on as it should.

The oil temp is usually at 1200 but got to 1:00 today.

I got home and "shot" the various radiator hoses with my thermo gun at it said anywhere between 198 and 206 depending on where I put the lazer.

My 82 C3 has some pretty good swings (190 -215ish) dependent on weather and if I'm using the AC. Howver it cools FAST and the LT5 seemed to hang on to the heat.

It sounds within specs to me, but this is my first LT5 so I don't know what is normal.

Thoughts and thanks!

WVZR-1

You can't rely on the C4 analog gauges! What year is this car? Different years have different information available that's substantially more accurate. An IR isn't very accurate either but I use frequently to confirm/challenge various readings that are displayed.

What I'd suggest you do is drive the car with a capable scanner and evaluate each of your analog gauges as to the display at what you consider "desired/normal" displays.

EVERY C4 is going to be VERY DIFFERENT - VERY - USE A SCANNER AND CONFIRM!!

What year? Oh - I asked that ..........

billschroeder5842

Sorry, 91

WVZR-1

You're restricted severely on a '91. You can retrieve CTS from the ATC control panel. '92+ there's more information available but differently. I'd do the drive with a scanner and confirm everything - while there confirm tach and with a GPS confirm odo/spdo.

billschroeder5842

Huh? Sorry, it is my first C4 so the acronyms throw me.

BTW, I just took it out for a 30 mile ride. The gauge was exactly where it should have been while at 60 mph and at speed. BTW...99% of the miles I've put on it have been at freeway speeds so that is my only real reference point

When I got back into town, the gauge started to climb a bit as I hit stop lights and especially poke through the neighborhoods.

I'll try to figure the diagnostics but I'm pretty sure that the car is real air flow sensitive?

WVZR-1

CTS (Coolant Temp Sensor)/ECT (Engine Coolant Temp) from the ATC (AutoTempControl) (C68). See the 1C1-3 thru 5 of the FSM for the information available through the ATC control.

FSM I trust you get?

billschroeder5842

Yep, got the FSM a couple of days ago. I'll mess with it this weekend.


Thanks!

mike100

the 94-96 cars have a digital readout of the water and oil temps on the orange center lcd display which are super handy, but to get those on the earlier cars, it's a bit of a trick. The analog gauges use different sending units- at least in the case of one of the readings.

The oil pressure sending unit near the oil filter is garbage. it wouldn't surprise me if you get the needle-all-over-the-place effect. just get another one- easy fix. the oil temp is probably accurate. C4's can run hot if the radiator is full of dirt and leaves and that will carry over to oil temp. If you are still on the stock chip, the fans come on awfully late- one of the reasons to chip these cars isn't for the extra power, but to program the rad fans to come on sooner (cooler). If you can get the a/c to come on (sorry lol) then it forces one of the fans to run all the time, which is a work around to cooling issues due to factory settings.

billschroeder5842

Ouch. My AC is dead at the moment and I need to get it going. I'm taking it in Tuesday and doing a 134 conversion.


BTW.. drove it today about 25 miles and had the needle exactly where it was during the 16 hour road trip.


Thanks for the advice.

FASTAZU

Have Marc do a chip for you.

http://www.zr1specialist.com/HAT%20W...librations.pdf

http://www.zr1specialist.com/HAT%20W...librations.htm

http://www.zr1specialist.com/HAT%20W...on%20BFXBG.htm