My gwm 2008 model 2.8 tdi .the rev is not exceeding 3 and sometimes it eluminates the engine check light and all cut out whilst in motion over 80km/hr

blue smoke is oil being burnt

Could you please recheck you've typed this trouble code correctly. The P0253 suggests it is a V12 engine! That TDi engine only has four cylinders.

Could be crankshaft sensor.

wow, no year, that makes this hard, huh?
NOR if full time fail or intermittent.
hot or cold engine or both?
parked or moving both ? even in neutral ? no rev.?
yes EFI is stupid , lacking tools. but carbs suck more.(endless stories i have, 50 years worth)

GMW, agents ,did you take it in running ok>? why do that.?
nobody can fix cars that run perfect, unless rich, and they keep it for one week $$$$$$$$$$$$$$
did you use a scan tool when it failed, if not, why not? working blind?
GWM. 2.8TDI.
chineese , Great wall Wingle , mfg?
TDI 101

1. clogged fuel filters, do the service in the book yet>??????
2. Check engine lamp on, ? ignored? yes its on
3. air cleaner packed, (full time fail)
4. bad fuel.
5. water in fuel
6. injection failure. (weak)
7. input to the PCM , reading wrong. (seem it is huh? CEL on)

no year posted so , that means you need to find out what scan
tools work on xxxx year car. if OBD2 type. any new scan tools works.

Have the dealer do the testing with special equip that can track down the problem.

Sounds like you have a fuel issue. It could be a fuel pump cutting in and out. It could be fuel pressure regulator, or an injector not spraying correct. I think it's time to find an honest educated repairman.

get your tires checked and maybe it could be in your front axles

Your problem sounds as if the thermo sensor....which controls the air fuel ratio when engine is cold....is faulty. It is a common fault on this model.
This is not an expensive part, and takes only a short time to fit.
Good luck
John

sounds like the idle speed sensor,if your rpm's are idling up and down

they are tempremental about the gas pressures you first need to check that the fans are working efficiently, if not the gas can freeze in the front core. also get your gas checked by a specialist
cheers