Why does the rpms get high when changing gears?

Question

2008-Present Scion xB

The second generation of Scion's box-shaped hatchback.

6 个问题查看全部

Melina Medina @melmed00182

声誉积分: 1

1

发帖于: 2019年3月27日

更多选项

Why does the rpms get high when changing gears?

I have an automatic 2012 with 108,000 miles. On cold start, car sometimes will have a high idle, but not too bad. The main problem is that the rpms get high when I shift gears. I've taken the car to 3 mechanics and they can't find the solution. There's no air leaks. Throttle body, throttle position sensor and mass air flow sensor replaced. I've had mechanic do a tune up, oil change and I got new battery. Transmission place told me the transmission is good, that it shifts hard because of the high rpms. I don't know what else to do. Thanks.

已回答！ 显示答案我也有这个问题

这是一个好问题吗？

是否

得分 0

15条评论

I think we'll need some more details. Is it happening when upshifting? Does it happen every single time the transmission shifts gears, or only at certain times? How high up do the RPMs get?

As for a high RPM idle during startup, that's completely normal as the engine tries to warm up from a cold start (usually no more than 500-1000 RPMs above a normal idle when warm.

由 Craig Lloyd 完成的 2019年3月28日

On cold start it goes upto 2000-2100 rpms, then it stays idle at 800 rpm. At shifting to any gear, it goes to 1500 rpm. On reverse it idles at 600 rpm. On other gears it idles at about 800-900 rpm. I hope it doesn't sound too confusing.

由 Melina Medina 完成的 2019年3月28日

So for example, when you shift from Park to Drive, it revs up to 1,500 RPMs? How long does it stay there before it goes back down?

由 Craig Lloyd 完成的 2019年3月28日

When I shift from Park straight to Drive, it goes from idle of 900rpms down to 600rpms right away.

But, if I shift from Drive straight to Park it goes from 600rpms to 1500rpms for about 3 seconds(about 10 sec total to gradually come down to idle 900rpms). Same with Reverse to Park and Reverse to Neutral.

由 Melina Medina 完成的 2019年3月28日

Have you found the source of the issue?

I have the same issue RPM goes to 1500 for around 3 seconds then back to 800.

This started right after I cleaned the throttle body. Nothing was wrong with the car in the first place but my itchy hands had to fix something that wasn't broken…

由 X S 完成的 2020年1月25日

显示更多的10条评论

添加一条评论

2个答案

已选择的解决方案

Craig Lloyd @craiglloyd

声誉积分: 35.3千

87

51

104

发帖于: 2019年3月29日

更多选项

Based on your follow-up comments, this all sounds like normal RPM ranges. 2,000 RPMs right at startup is normal, just as long as it goes back down after a few seconds or so. (it may stay higher for longer when it’s really cold out).

As for shifting into Drive, the RPMs will slightly go down because the engine connects to the transmission, and the resistance of the transmission fluid takes energy from the engine and lowers the idle speed slightly. Vice versa, when shifting into Park, the RPMs will go up temporarily because that resistance is no longer there. Your car’s computer will notice this and bring the idle RPMs back down to the normal 800-900 RPMs.

That’s all a bit oversimplified, but I hope it makes sense. There doesn’t appear to be anything wrong based off the info you gave.

这个答案有帮助吗？

是否

得分 2

2条评论:

What if the car is automatic. U dear normal conditions, what rev range should it change gears. I have a clk 200 2009., 1.8.

由 Alan 完成的 2020年4月5日

What is the normal RPM when gear up on auto transmission car? for example from 3rd to 4th, or 4th to 5th. my BT-50 is 2000rpm is that normal?

由 Coca 完成的 2022年9月27日

添加一条评论

I think we'll need some more details. Is it happening when upshifting? Does it happen every single time the transmission shifts gears, or only at certain times? How high up do the RPMs get?

As for a high RPM idle during startup, that's completely normal as the engine tries to warm up from a cold start (usually no more than 500-1000 RPMs above a normal idle when warm. — Craig Lloyd
On cold start it goes upto 2000-2100 rpms, then it stays idle at 800 rpm. At shifting to any gear, it goes to 1500 rpm. On reverse it idles at 600 rpm. On other gears it idles at about 800-900 rpm. I hope it doesn't sound too confusing. — Melina Medina
So for example, when you shift from Park to Drive, it revs up to 1,500 RPMs? How long does it stay there before it goes back down? — Craig Lloyd
When I shift from Park straight to Drive, it goes from idle of 900rpms down to 600rpms right away.

But, if I shift from Drive straight to Park it goes from 600rpms to 1500rpms for about 3 seconds(about 10 sec total to gradually come down to idle 900rpms). Same with Reverse to Park and Reverse to Neutral. — Melina Medina
Have you found the source of the issue?

I have the same issue RPM goes to 1500 for around 3 seconds then back to 800.

This started right after I cleaned the throttle body. Nothing was wrong with the car in the first place but my itchy hands had to fix something that wasn't broken… — X S
What if the car is automatic. U dear normal conditions, what rev range should it change gears. I have a clk 200 2009., 1.8. — Alan
What is the normal RPM when gear up on auto transmission car? for example from 3rd to 4th, or 4th to 5th. my BT-50 is 2000rpm is that normal? — Coca

herbert batres @herbertbatres 声誉积分: 1 · Answer 1 · 2022-01-06T21:13:31-07:00

herbert batres @herbertbatres

声誉积分: 1

发帖于: 2022年1月6日

更多选项

try changing the engine oil pressure sensor i had seen that before n believe it or not it had work on 3 cars i had fix having the same problem try doing that n let me know if it works for u guys

这个答案有帮助吗？

是否

得分 0

添加一条评论

2008-Present Scion xB

Why does the rpms get high when changing gears?

2个答案

添加你的答案