JoesC5

Actually he said...."I do know that in pervious models the digital gauge and the analoge gauge are fed by two different sensors in two different locations".

There has been two generations of Corvettes built since the C4, and they are previous generations to the C7. He did state that his old C4 LT1 had two sensors, but since the last two generations didn't have two sensors......

My C1 and C2 and C3 and C5 and C6 didn't have two sensors............

Not saying the C7 LT1 doesn't have two sensors but the odds are 5 out of 6 that it won't.........if you look at previous generations, which he referred to.

Bill Dearborn

Never paid any attention to how they did it in the later C4s but I have a hard time believing they used such an antiquated method to drive the instrument package. Using two sensors to feed analog and digital gauges was 10+ years behind the state of the art in 1991. Maybe it was just because the car had been designed in the 70s and they saw no need to redesign the early C4 digital data stream and just added the analog gauges.

The C5/C6 had one sensor. The ECM would read the sensor and send a digital data stream to the IPC and the HUD. The IPC would do an electrical digital to analog conversion to feed the analog gauges, the HUD converted everything but the speedo info from digital to analog while the DIC just displayed its info with no conversion. Much simpler design.

Here is the description of how the C6 IPC gauges get their information.
Engine Coolant Temperature Gage
The IPC displays the engine coolant temperature as determined by the engine control module (ECM). The ECM monitors the engine coolant temperature sensor. The IPC receives a serial data message from the ECM indicating the engine coolant temperature. The engine coolant temperature status message is also displayed in the DIC. The engine coolant temperature gage defaults to the lowest position possible if:


As for the OP the DIC readings of the oil and coolant temps are in the correct range. He can avoid calling the tow truck (and the major PIA of getting it safely loaded on the truck) and just drive the car to the dealer. Oil temp is the critical temp and if there is a real issue with the cooling it will climb high and fast. On top of that if the ECM detects the temperature as being too high it will put the car into limp home mode which will prevent damage.

Bill

lt4obsesses

Bill, I believe that they may have used the two sensor set up on the '92-'97 LTx motors due to the reverse cooling feature of that engine. On those engines, they used reverse cooling to feed the cooler water to the heads first to prevent detonation due to the higher, 10.5:1 (LT1) and 10.8:1 (LT4) compression ratios. I can't recall at the moment what the comp ratio is on the Gen V. But on the LTx motors, discrepency between the analoge and the digital was commonplace, and the digital was the one we look at more closely. That was the technology of the time.

I believethere was only one temp sensor on my LS1 Camaro, so this is probably true of the later editions of the LS series. However, this car did not have a digital read out either.

I do agree however, that this should be looked at.

TheYoungster

Ambient was about 14 degrees this morning. And I agree. I've never seen it warm up that fast.
Thanks

Wormwood

I understand the analog temp gauge gets it's positioning directly from the ECU. Since the vehicle can change units of measure, but only has a single numerical range, I'd assume the ECU does the calculation & outputs the voltage to position the needle accord to which units are currently selected.

Is this correct?

TheYoungster

The engine fan did not come on at all when this was occurring.

Thanks

BlueOx

That tells me exactly what I said in my first response...181 degrees isn't that hot and as such the fan isn't turning on. Have you called the dealer yet?

vetteLT193

I'm not sure if it was reverse flow cooling or simply different pieces of information. On the LS they moved the temp sender to the forward part of the drivers' side head. On the 90's LT1 the senders were in the water pump (digital) and passenger head (analog). This may have been a partial carryover because in the L98 there were two but one went to the computer and one went to the gauge.

On the 2014 LT1 I know there is a temp sender again in the water pump. I'm not sure if there is a secondary or not.

It seems to me the head would give more accurate overall temperature while the ones in the front (90's LT1 water pump, L98 was near the water pump, and the new LT1 is water pump) would give better data as to when to run the fan(s).

TheYoungster

Yes, I'm dropping it off at the dealer this evening and they will look at it tomorrow. I sent them the picture and their Stingray Engineer said he would be comfortable with me driving it there as long as it has Coolant at the normal levels in it.... I'll check coolant levels this evening.

c54u

As long as the Stingray Engineer is comfortable being liable for paying any damage that may occur!!! Warranty or not.

TheYoungster

Started it up when I got home this evening and now everything is operating in normal parameters. pic below.

Notice the voltage is now normal too. I think someone picked up on it being too high in the first pick. maybe the voltage problem was the source of problem.

a few weeks ago when I had PTM and rear axle issues the code in the computer was a high voltage code.

I'll keep an eye on it now to see what happens.

455230

No way oil temp would be 131 deg with a coolant temp of 240+ deg

BlueOx

Glad to hear it is back to normal. So you never got it to the dealer, right?
It seems odd that these warnings and strange gauge readings are happening.

brokenparts

voltage regulator? sounds like you have electrical issues, might be time for a new alternator.

Hope you get it figured out before anything major happens

Pinstriper

Not to change the subject but I want to have the same look on my instrments (where you have the arrow pointing) but have not been able to find and apply. Can you give any hints/ideas how to do this? Thanks!

hogpup

The analog gauge is bad, The digital is correct.

Pinstriper

How do I set the different temperatures net to the center tack as in the last picture above.