Fluctuating RPM's when driving 65 MPH

Hi,

Is the check engine light staying on when the engine is running? It could be a few different things. If the light is on all the time, we need to scan the can-bus system. Can stands for controller area network. Basically, all the computers and modules are tied together. Here is a video showing how this is done:

https://youtu.be/InIlnsjOVFA

That is where I would start. Let me know if this helps, if you have questions, and what you find. Once you get a code or codes, I will be able to direct you much more efficiently.

If you can't have this done, let me know. I will try one thing at a time until we figure it out. I honestly don't feel it is transmission related, but the codes will tell us where to go as far as repairs.

Let me know.

Joe

Hi,

Okay, is it possible for you to record what it is doing so I can see it?

As far as the RPM issues, it can be a fuel pressure-related issue, an engine vacuum leak problem, an issue with the throttle body, and so on. Without a check engine light, it makes it more difficult because we have no direction other than what we know could cause this type of problem. I will need you to check a few things.

Since there is no check engine light, first check to see if there are vacuum leaks. Here is a link that explains how it's done and what to look for:

https://www.2carpros.com/articles/how-to-use-an-engine-vacuum-gauge

I'm suggesting starting with that simply because it is the easiest thing to do and it can cause the symptoms you described.

Let me know what you find and if you can upload a video showing the issues.

Take care,
Joe