Tachometer not working

DIANE HOPKINS

MEMBER
2005 CHEVROLET CAVALIER
2WD
AUTOMATIC
129,000 MILES

Just purchased, didn't notice until driving home RPM gauge not working?Does this impact the cars performance, or damage any thing?Also could you tell me what temperature it should be running at? I was watching temperature just in case.

Wednesday, July 15th, 2020 AT 8:58 PM

1 Reply

JACOBANDNICKOLAS

MECHANIC
109,885 POSTS

Hi,

The thermostat in the vehicle should fully open at 195°F. It is normal for the engine to run a bit higher. For example, 205° or slightly higher. It shouldn't go over 210°F. That is getting into an area of concern. Let me know if that is the case.

As far as the tachometer, it is part of a network of modules and the instrument panel cluster (IPC). To check this would require a live data scan tool. However, if an RPM signal is identified at the power-train control module (and there should be if it runs), the IPC would need replaced. I attached a simple flow chart below. In this case, a live data scan tool would be used to see if there is an RPM signal. To answer your question, it shouldn't hurt anything from not working.

Let me know if you have other questions and if this helps.

Take care,
Joe

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