MSFS 2024, engine spike issues at KIAH, HOU

[debbert]

Since SU4, I, along with many other users are observing engine spiking issues around the Houston area. For me, this has occurred on the PMDG 737, 777, and the IFly 737 (at the very least). Prior to SU4, these issues didn't exist. This has been reported to PMDG by myself and a few others, HOWEVER, please read below regarding Coutal.

Additional users have reported that killing Coutal solves the issue. This is not a binding issue, community folder issue, etc. Those fixes have been attempted, and we have narrowed it down to what we think it is, something going on with Coutal. This issue is also ONLY happening below 18,000 feet, noticed shortly after departure up to 10,000 for the most part.

I want to reiterate that this engine spike issue is ONLY in the Houston area. For example, on climb out from IAH, or HOU (a video I will attach as a reply).

Here's an example I took, 777 departing out of IAH: This issue is duplicated at the very least, in the 737-800 and the IFly.

https://youtu.be/zd9tiHLoJz4.

Best,
Davis

[Wise87]

I'll add to this topic as we were doing a MSFS2024 group flight in and out of the Houston area today with the PMDG 737 and 777. Of those flying the 737, we encounter our throttle fluctuating and our autothrottles kept disconnecting and we couldn't get them to engage until we turned Couatl off. Then the engines operated normally and the plane flew fine. With the 777, taxing around the airport was fine but the moment we left the ground, the engines would surge and move all over the place. The plane throttles would move individually without input from users. We all had single axis configured for both engines. Once we turned Couatl off or got above 10,000 feet and away from the Houston area did the plane operate fine.

Yes I notified PMDG but I'm also posting here as turning off Couatl fixed the issue. Here is a video link of a user have the issue. During this flight we didn't discover that turning off Couatl fixed the issue. https://www.twitch.tv/videos/2658864169

[debbert]

Here is the evidence on the newly released 737-800 as well. Notice how on this one, the Auto Throttle flicked off, and it's still spiking N1. On departure at Houston Hobby (HOU).

https://youtube.com/shorts/7OWMHbhuEYc?feature=share

[Keirtt]

I was absolutely pulling my hair out the other night with this issue and experienced the same thing!! I'm glad I came across this thread because sure enough, I was in the area of HOU when it started happening. Was flying from BNA-SAT and over HOU my throttle kept disconnecting and engines were surging with the PMDG 737-800. Glad it's not just me!

[debbert]

I was absolutely pulling my hair out the other night with this issue and experienced the same thing!! I'm glad I came across this thread because sure enough, I was in the area of HOU when it started happening. Was flying from BNA-SAT and over HOU my throttle kept disconnecting and engines were surging with the PMDG 737-800. Glad it's not just me!

I’m right there with you! It’s been very frustrating because you basically need to avoid the Houston area. I hope Umberto provides a fix soon. More and more people are reporting the issue in various communities. Reported to PMDG but after testing and other users we know it’s Coutal.

[TheDavid737]

I’ll add to this. I’ve been having this same issue in the iFly max8 as well as the PMDG 737-800 in the Houston area. I first experienced it with the max 8 on the SU4 beta, so I switched back to the main SU3 release at the time, and the issue went away. Then after the general SU4 release, the issue resumed.

I am not sure if relevant but I also could not load into the sim in the Houston area with Couatl running during the general SU2 and SU3 releases (specifically IAH). Now with SU4, I can load in to the Houston area with no issues except for this engine issue.

Link for the mentioned IAH/GSX issue: https://www.fsdreamteam.com/forum/index.php/topic,33602.0.html

[szln6z]

I'm also having this issue arriving and then departing from KIAH.  Nothing more to add from what everyone says above. 

[szln6z]

we couldn't get them to engage until we turned Couatl off. Then the engines operated normally

How do you "turn couatl off."  I've restarted the couatl engine from the GSX menu multiple times and the engine surging continues.  I cannot figure out how to "turn off" GSX.

[TheDavid737]

we couldn't get them to engage until we turned Couatl off. Then the engines operated normally

How do you "turn couatl off."  I've restarted the couatl engine from the GSX menu multiple times and the engine surging continues.  I cannot figure out how to "turn off" GSX.

From the windows taskbar in the bottom right you might have to click the little ^ to see it but there is a Couatl icon there. You can right click that and either exit or restart.

[szln6z]

Ahhh, thanks!  Had no idea it was on the taskbar.  I see it in task manager too.  Looks like it can be started by running the .exe in the GSX program folder.  I'll test this letter, but at least it seems like a workaround for flying into and out of the Houston area.

[TheDavid737]

Ahhh, thanks!  Had no idea it was on the taskbar.  I see it in task manager too.  Looks like it can be started by running the .exe in the GSX program folder.  I'll test this letter, but at least it seems like a workaround for flying into and out of the Houston area.

Yeah unfortunately some of us have been having to disable Couatl in the Houston area since SU2 for a couple of reasons. Hopefully there is information we can provide to Umberto to help troubleshoot further.

[szln6z]

This isn't really new news, but I just spent a good 60 minutes flying the 77L around KIAH with couatl.exe either running or not.  Can confirm engine spikes occur with couatl.exe running and cease with it shutdown.  Certainly odd, but it's consistent and repeatable.

[debbert]

This isn't really new news, but I just spent a good 60 minutes flying the 77L around KIAH with couatl.exe either running or not.  Can confirm engine spikes occur with couatl.exe running and cease with it shutdown.  Certainly odd, but it's consistent and repeatable.

This is great news. I hope Umberto replies soon with a fix!

[debbert]

Umberto,

Any updates regarding this widespread issue?

Thanks!

Davis

[szln6z]

More users over on the PMDG forum experiencing the issue.  https://forum.pmdg.com/forum/microsoft-flight-simulator-2020-2024-products-discussion/pmdg-777/general-discussion-aa/377670-su-4-772-engine-power-spikes