Is this Limp Mode?

First posting, but want to thank everyone for valuable DIY/fixes/advice.
Over the past few summers, while in stop/go fwy traffic, ambient temps 100° or more, after traffic thins out, try to speed up; rev's go up no problem, but there's just no torque behind it. No MIL.
After exiting to safe place, re-start engine and all is well. This has happened a handful of times, always in very hot weather after crawling for 15-20 minutes.
Why I ask if this is a type of Limp Mode is that in articles I find on the subject, no mention of LM under the described circumstances.
Read MAF testing, have not done VCDS logging or measurement yet, but article mentions:
"warm up the car to normal operating temperature and put the transmission in neutral. Rev the engine up to redline in neutral. If the MAF is good, it should go all the way up to the rev limiter at 5100 rpm"
Mine does not exceed 2500 RPM when I do this.

Any comments?

Thanks

Mark

Cannot answer specifically on limp mode, but I have had a '96 1Z TDI do that without a MIL. Not certain about the newer ones.

For your test though, do you have the clutch depressed? My understanding is you will not be able to exceed 2500 RPM with the clutch peddle in. I'm not in the JSW today so cannot test it though.

I have the DSG. Does the same in Park as well as Neutral.

Revs limited to 2500

Try turning your traction control off, you should then be able to rev the car freely

Thanks mtondat
Did that and engine revs to redline.
I'm thinking it might be hot ambient air intake, so thinking of doing the MAF alcohol cleaning posted elsewhere. Can't hurt if done properly.

Not a problem, glad to help! As per your true problem, I'd love to help out but I've never experienced anything like that and so I don't want to give you bad info, good luck though on solving the issue. please update once you know as I would like to know what the problem really is

It could be a heat soaked intercooler. If it's above 100 out there, you have the air on, maybe the radio, I wouldn't be shocked to see a reduction in power. Maybe your car overheated slightly while sitting in traffic and then the intercooler wasn't functioning properly. It could be a thermostat maybe, but I really have no idea and have no experience with this. I'm just throwing ideas around.

Thanks Gloaming
After perusing some posts, I believe I need to look at the IAT sensor.