Starting at low temperatures and sitting all night outside at below 5°C my car starts "slow". Like you can see in the video below, it will start with no problem but the engine hangs at 700rpm for a few seconds and only then it will start up the electricity (in the cabin and also main lights) and revs a little harder (which should be normal from the begining). There are no DTCs, glow plugs were changed last year, car starts normally when warm, battery was changed last year, fuel filter 10.000km ago with OEM, EGR and throttle body cleaned. I have no slightest clue what could be wrong.
There's another problem when engine is warm (if that issue is somehow connected to this one). There's pretty noticeable rough idle when stopped and also RPMs fluctuate when coming to a stop. Interesting here is that rough idle at stop dissapears when I turn ON the AC or steer the wheels (put a load on the engine).
Car: Volvo s80 w/ 360.000km (220.000 miles)
Model Year: 2009
Engine code: D5244T5
Transmission: Manual M66
- I've also did a injector delivery volume test with Volvo VIDA software, which showed no major differences between all five injectors.
- The other day I've open the oil fill cap and discovered the popping sound, so I think I've got a vacuum leak. This is regarding the warm engine problem (rough idle)
I managed to eliminate roughness in engine at idle when hot by treating the engine with diesel additive (2 liters of it - one liter per 1/8 of tank). Engine now idles as smooth as ever.
Still can't figure out that cold start problem, if anyone has any idea? Car still has no DTC codes and drives like a charm. Currently at 370.000 km.