Hi all,

My sport still goes in to limp mode when gently accelerating which I believe is a relatively common problem on the 4.4tdv8.

I recently bought a smoke machine and completed a smoke test. No smoke came out of anywhere but I couldn’t build up any pressure when testing. Now in my head it should be a sealed system and therefore it should be able to hold pressure and certainly from a small smoke machine which when blocked with my finger builds pressure no issues…

I’m hoping the collective knowledge of you brainy lot can point me in the right direction.

Thx 2015 4.4 Autobiography
2010 3.0 HSE 162K - Gone

Last edited by PC76 on Tue May 07 2024 12:27am. Edited 1 time in total

Not really. It fills the induction system and inlet manifolds. Then bypasses the piston rings and through the CCV, back into the air intake

Unless your putting a ridiculous amount of pressure into the system, you won't see a huge pressure increase

Thanks for the response DM.

I thought it maybe a duff EGR but never thought it would get past the piston rings.... (you learn something everyday!)

so that leaves me with the software update I believe was mentioned on the full fat site so will get that sorted with GAP. (would be interested to know what they change in the mapping to resolve)


Thanks. 2015 4.4 Autobiography
2010 3.0 HSE 162K - Gone

Ok so after updating the ecu it now appears to have “fixed” the problem.

I was experiencing a reduced performance issue when accelerating using light throttle or whilst towing up hill, this happened in normal or sports mode. It did not show when accelerating hard.

A xsmoke test did not show any leaks within the intake system.

The fault read with IID was-
P006A-84 (27) Manifold absolute pressure - mass or volume air flow correlation - Bus signal/message failure - signal is below allowable range.

The ecu details both pre and post below.




 2015 4.4 Autobiography
2010 3.0 HSE 162K - Gone