Hello, my 2013sd Auto seem to be lumpy at idle. Its fine for say 15-20s second then lumpy for 2 or 3 seconds, then fine again - it repeats this pattern.

I dont really know where to start.

I have done a live scan on Autel AP200 and wondered if this gave any clues to anyone?

Many thanks
Mark

Sounds similar to my issue. Does it do it when in neutral and air con switched off?

I try that tomorrow. What would this indicate?

Thanks - Mark.

i havent had chance to start looking for the cause yet, and was hoping to get some ideas of where to start looking on here but not much has come back yet. if i do find anything i will post up.

Is it due to varying load on engine from something like hydraulic steering pump, air-conditioning pump, or electrical alternator load? Of course these would only be symptoms of an underlying problem.

This similar post ended with clogged filter in steering pump
https://www.freel2.com/forum/topic39369.ht...p;start=30

Have you tried searching for 'Idle' problems?
https://www.freel2.com/forum/search.php?se...rch_time=0 FL2 XS SD4 Auto 2010 2012-2017 (21k - 91k miles) (MY2011)
FL2 Metropolis SD4 Auto 2014 2017- (16k - 76k+ miles) (MY2015)

I’ll have a look at the power steering fluid tomorrow - thanks for the idea.

Sounds similar to mine a couple of years ago. Noticed the air filter cover was not tight to the main body and air was leaking into the body intermittently making the idle speed go up and down by a similar amount. Problem solved by making sure the cover securing screws/bolts were doing their job and the threads in the plastic not stripped and allowing cover to move. Worth a look as an easy fix.

Thanks for the suggestions. I changed the Power Streering fluid, but no change.

I think i have the problem - the charge pressure air tempreture sensor, is i think not getting a power feed to it. I have ckecked the plug to it with a multimeter and can not find any 5v supply.

Click image to enlarge