So I will admit this is the first car I have driven with a LCD tach, but it has been annoying the piss out of me so I thought I would ask if everyone's is this way.

I have been driving my car when it was cold and snowy recently (17 degrees F out) and I noticed that the LCD lagged behind a LOT depending on how cold it was. The colder it was the worse the lag was. Now the car is stored in a partially underground garage with insulated doors and it only got down to about 30ish in there. The worst time though was on the way to work one morning I bounced off the rev limiter when the tach was only displaying 6500ish rpms in good solid color, and some really hard to see greyish after that, but not up to 8k rpm... Seemed like anytime I ever got close to to 6600 quickly I'd bounce off the limiter before the tach reached 8k.

Anyone else experience this? Any fix besides buying a massive ricer tach?

Car is a stock MY04.

 

Its not lag, its the cold engine rev limiter.

 

Agree with above. Sounds like your thrashing a car with a cold engine, there is no display lag.

 

So how many bars is warm enough? I had this happen at 4 bars before.

Next time it is über cold out again I will take a pic by what I mean by laggy or ghosting that takes a while to go away.

 

So are you definately hitting 8000rpm but your rpm counter isn't? I can 100% say in my car i know when i am at the redline without having to look at the gauge. The sound is unmistakable

 

You are talking about 2 different issues.

Issue #1. The bouncing off at 6500. That is the cold engine rev limiter. The ECU will not allow the car to enter VTEC when the car isn't up to temp.

Issue #2. Laggy instruments. You answered your own question. It is an LCD. The liquid in LCD's gets cold, and as a result, gets thick. This makes it react slower. This is true for any form of displays, including headunits, navigations, calculators, etc. This is normal. When the inside of your car comes back to a normal temperature, the display will speed up and be back to normal.

 

^ Bingo! I've seen several comments around various forums about slow LCD response; I think it's related to Global Warming.

 

Stupid damn polar bears.

 

I've been trying to find more information about this tachometer lag. It's definitely more noticeable when it's cold out, but even here in sunny southern california on a hot day with the engine fully warmed I'm still hitting the rev limiter a split second or two before the tach redline light even blinks once. (I know that it's supposed to blink 3 times before hitting the rev limiter).

Has anyone else noticed this on their S? It's quite annoying and I believe that the tach is slow to respond by around 150-200 rpm's... Granted I realize that because it is a digital gauge that the tachometer "discretization" threshold needs to be passed before the tach "ticks" up 1 notch, but it still seems far too laggy.


Clarification:

Between each numeral on the tach, there are only a discrete number of tick marks, which means that there will be a wait time before the tachometer displays the next tick mark.

For instance as you accelerate between 2-3k rpm's, there are only around 10 "tick marks" between the number 2 and 3. Assuming that the ticks are evenly spaced, let's say that each tick represents 100 rpm increments. eg: as you accelerate, the tach can only display 2000, 2100, 2200, 2300... 2800, 2900, 3000 rpm. Now, I'm not sure how it's programmed, but at some rpm it has to decide when to move to the next "tick". If you are at 2000 and you accelerate to 2020 rpm, it could still display 2000 rpm on the tach as it has not yet "rounded" up to 2100, or perhaps you have to hit 2100 before it displays the corresponding rpm.


What I'm saying is that when my tach displays 2100, the engine feels more like it's at 2250 or so. How would I be able to tell this you ask?

While I'm not able to discern between 2250 and 2100 rpm in actuality, when I'm in 1st gear and flooring it, the engine rev limiter will kick in before the tach has had the chance to blink the reline indicator even once. (With engine FULLY warm car could have been running for hours and it will still exhibit this issue). The rev limiter kicks in first, and then the redline indicator starts blinking... This is the "Lag" I'm referring to...


Does ANYONE else know what I'm talking about? This is driving me nuts, and I can't tell if it's just my car (bought it used with some aftermarket alarm) or this is normal... there are very few instances of anyone mentioning anything similar to this.


I'm afraid it might be whatever aftermarket alarm the previous owner installed, however I don't want to start ripping things up unless I'm sure. Could the aftermarket alarm system be interfering with the tachometer signal somehow?


edit: I realize that this is posted in the "electronics" forum, but aftermarket alarm systems in particular bother me as I have experienced nothing but trouble from them on my own and other people's cars, especially when the car battery is low...

Any help for this philistine would be greatly appreciated from the electronics gurus!

 

The crystals in a liquid crystal display can get slower in cold weather. That may be one source. The electronics may be slowing up, but unlikely. If you see a shadow chasing the tach lines on their way down, it's cold lag.