Tachometer has a mind of its own

[Bjakub82]

I wanted to share and get the group’s opinion. I have a 2020 AWD S with about 57k and recently started noticing a strange acting tachometer during acceleration. This isn’t every time but can happen when speeding up to get on the highway or just in the city under mild acceleration. It definitely does not follow the engine note as if it has a mind of its own. Has anyone else seen this?

I have a video of it I posted on the Telluride FB page since I can’t post it in here. Link is below.

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[Theauharem]

I wanted to share and get the group’s opinion. I have a 2020 AWD S with about 57k and recently started noticing a strange acting tachometer during acceleration. This isn’t every time but can happen when speeding up to get on the highway or just in the city under mild acceleration. It definitely does not follow the engine note as if it has a mind of its own. Has anyone else seen this?

I have a video of it I posted on the Telluride FB page since I can’t post it in here. Link is below.

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I have noticed some odd behavior recently following an oil change at the dealer (not that it’s related). The tachometer seems to jump around and be generally ‘swingy’ like it’s gear hunting or slipping without anything really being apparent with the car itself. Does this represent what you’re experiencing?

 

[Bjakub82]

I have noticed some odd behavior recently following an oil change at the dealer (not that it’s related). The tachometer seems to jump around and be generally ‘swingy’ like it’s gear hunting or slipping without anything really being apparent with the car itself. Does this represent what you’re experiencing?

Yes that is a very good explanation of what I'm seeing as well. The car it self seams to be driving fine. I have had a couple rough shifts in the last few weeks I noticed but hard to say if its related. I am 3k away from my next appoint but might be making an appointment in the next few weeks to have them look at it. At a minimum see if they can review the video and tell me if they have come across this before.

 

[Theauharem]

Let me know what they say. Anecdotally I seem to be dining a few more rough shifts as well but not sure if it’s my imagination or actually the fact I’m at 50k+ km. If I didn’t know better, I’d say it was a hydraulic pressure issue in the transmission - that would explain the floaty tach and rough shifts. Is the transmission fluid for life or is there a change interval?

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[James]

Yes that is a very good explanation of what I'm seeing as well. The car it self seams to be driving fine. I have had a couple rough shifts in the last few weeks I noticed but hard to say if its related. I am 3k away from my next appoint but might be making an appointment in the next few weeks to have them look at it. At a minimum see if they can review the video and tell me if they have come across this before.

I think on this car, the tach shows you where the RPM's plan to go , not where the are.

 

[Bjakub82]

Let me know what they say. Anecdotally I seem to be dining a few more rough shifts as well but not sure if it’s my imagination or actually the fact I’m at 50k+ km. If I didn’t know better, I’d say it was a hydraulic pressure issue in the transmission - that would explain the floaty tach and rough shifts. Is the transmission fluid for life or is there a change interval?

Last I remember checking, under "normal" driving KIA does not have a recommended change interval on the transmission. Under "severe" its every 60k. About 10% of my miles are towing at travel trailer so I will probably have them change it and have them do an inspection at that point if I don't have them do it sooner.

 

[Theauharem]

I think on this car, the tach shows you where the RPM's plan to go , not where the

Last I remember checking, under "normal" driving KIA does not have a recommended change interval on the transmission. Under "severe" its every 60k. About 10% of my miles are towing at travel trailer so I will probably have them change it and have them do an inspection at that point if I don't have them do it sooner.

Up here in Canada, the entire country is considered severe conditions (in terms of oil changes anyway) so I’ll be doing the same at my next visit.

 

[Theauharem]

So just a quick update on my side. Windy day today and I noticed the same floaty tach a little bit. Of note, 8th gear according to the cluster, engine turning at 2500 rpm at 120 mph (~70mph) which is substantially higher than normal. If I plopped into manual and downshifted to 7th, the revs rose further. Almost seems like the torque converter isn’t locked at speed allowing the engine to rev higher than the gearing would allow - this may be a torque converter fault or a programmed feature.

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[Theauharem]

So just a quick update on my side. Windy day today and I noticed the same floaty tach a little bit. Of note, 8th gear according to the cluster, engine turning at 2500 rpm at 120 mph (~70mph) which is substantially higher than normal. If I plopped into manual and downshifted to 7th, the revs rose further. Almost seems like the torque converter isn’t locked at speed allowing the engine to rev higher than the gearing would allow - this may be a torque converter fault or a programmed feature.

This would explain a floaty tach at lower speeds since revs would be determined by hydraulic pressure in the tranny and ECU programming rather than gearing and car speed.