3rd Gear Power Loss Fiasco

[DannyXD]

Hi Guys,

 

Got a new issue with my Accord EX 2.2Cdti 07 which appears linked to previous "mends" made - so I think I need to research this further...

 

I was driving today to work when suddenly transfering to 3rd, the revs slowly decrease. This despite being fully in gear and with my foot down... no power. Pulled over, restart and can pull away but same issue when going back into 3rd! Pull over... etc. Then I decided to skip 3rd into fourth, same reaction.

 

The curious thing is that it doesnt stall the enigine - almost as if the engine ignores all throttle input and goes to idle @ ~800rpm (although Ive yet to allow it to) once put into 3rd.

 

Checked for codes - nothing... I'll be scouting the internet further but I'm wondering, why only in 3rd gear?

 

Background:

A month before I had a MAP sensor replaced due to a similar issue, no power & no stall in 1st/2nd gear. A week after, EML came on and so got the EGR cleared of significant buildup! It ran a bit weird (sounded like rpm was going up n down every second) in 3rd when cruising at 30mph... so redexed and it subsided... 

 

TLDR: Car loses all power once into 3rd, returns to idle at 800RPM and doesn't stall.

 

Any advise or suggestions are welcome. After twice taking it to a garage and returning similar issues, I'd feel good having more than one voice to hear.

 

 

[DannyXD]

I suspect this is purely a sensor issue reading high/low... but only in 3rd.

 

I understand this may come from the EGR sensor - reason being is the EGR should only be activated during engine cruise or in low acceleration so perhaps 3-6th are where EGR is allowed to operate. 

 

So probably the MAP/MAF that was initially replaced.

Awaiting ECU data logger to hopefully track which sensor is faulty.

Edited November 11, 2022 by DannyXD
Clarify

[DannyXD]

Potential source of the issue found while monitoring the car.

Coolant reached 118C and gradually became unresponsive to throttle - so yes, it was a wee bit low!

 

OBD log and plot attached.

 

I've put boxes around the first drop in power and then 2nd. This came after ~10mins of driving and luckily I noticed the temp gauge too.

Voluntarily restarted 2nd box to rule out 3rd phenomena.

 

TLDR: Keep your coolant filled up!!!

 

trackLog-2022-Nov-13_11-09-39.csv