I have a 2012 5.0 HSE and I've cleaned the MAF sensors, done a coolant, transmission and oil change, and I still have an issue where the engine ( after idle and under load or cruising) will predictably surge about 100 rpm. Has anyone else experienced this?

I've scanned it and the only codes that I think may play into this are B11DB-87 battery monitor and B12C9-88 LIN Bus

While it's very slight and the the vehicle is 100% drivable but as a "new to me" vehicle I want to sort out everything that I can so I can just enjoy it.

Any tips of troubleshooting ideas would be appreciated.

Yes there is a thread going on at the moment on this very issue

https://www.fullfatrr.com/forum/topic72665.html

Thank you for the quick reply. However, my issue was just a slight bit different. My transmission is very smooth and functioning correctly. It's the actual speed of the engine that varies in that slight amount. Initially, I thought it might have something to do with the MAF sensor or air filter, restricting the amount of fuel air mix.

I'm trying my best not to take it to the main dealer, but I feel like I need to bite the bullet and just let them do a full diagnosis and maybe then I can get a list of items that I can begin to service myself versus pay the shop to knock out.

Quote:

It's the actual speed of the engine that varies in that slight amount.

Thanks Phil. Looks like I'll take a run a the solenoids first and pray that sorts out the issue.

This is 100% what my car was doing when RRPhil helped me diagnose it. I've done around 6000 miles in it since replacing the solenoids and servicing the gearbox and she's been perfect since!

Other than not locking up properly the gearbox on my car felt like it was perfect too. I did oxygen sensors, MAF and MAP sensors, checked for vacuum leaks, etc. etc. before realising it was the gearbox.

David. 2002 4.6 Vogue SE - Alveston Red with Lightstone Leather
2012 Range Rover 5.0 SC Autobiography in Indus Silver with Jet/Ivory Interior
2012 Range Rover 4.4 TDV8 Autobiography in Baltic Blue with Sand Interior

Out of curiosity

What would a ZF service centre / Indy charge for a complete change of solenoids in the ZF8 gearbox ?

I think you need to ask that of a zf gearbox centre