C5 2.2HDi 170 is slow at acceleration

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Vallunstein297
Posts: 7
Joined: 31 Oct 2020, 16:29

C5 2.2HDi 170 is slow at acceleration

Post by Vallunstein297 »

Hi everyone!
Over 10 days ago,a problem on my C5 occured. When the car is cold,it functions normally,and it's acceleration is what it should be. However,when the car warms up,a big problem occurs. When I put my foot on the pedal (to the metal :lol: ) the car barely accelerates,and when It goes to higher RPM's (say 3000) it starts to move very quickly.
I'm sure some of You have had this problem. Question is,what could be? My best guess would be
-Air Flow sensor
-High Pressure Fuel Pump
-Fuel Filter clogged.

P.S.- If anyone is kind to provide any links connected to this issue,I'd be very grateful! :wink:
mrpedersen38
Posts: 19
Joined: 11 Dec 2019, 10:46
x 2

Re: C5 2.2HDi 170 is slow at acceleration

Post by mrpedersen38 »

Air flow sensor is a good place to start but maybe your luck is as bad as mine.
I Have an 2.2 204hp model from 2012, my turbo died on me, and i had EXACTLY those symptomes.
on the 2.2 the Turbo is not vacuum controlled, but electronically. The mechanism from the servo to the (VGT) turbo itself was worn out and Very loose.

i could reach the turbo actuator arms from above the engine and feel they were very loose.
i changed the turbo with a brand new one, and the car ran perfectly ever since.

BUT check the mechanism controlling the VGT before jumping to conclusion!

They should NOT be loose or feel "sloopy" in the joints.
It's a common fault on the 2.2 turbo's from Mitsubishi/garret.

It could be a combination from the vibrations and heat from the motor jerking the mechanism to actuate the VGT in the turbo.
Mine were so bad i could slam the brakes and gas pedal at the same time and then the turbo would kick in! :D
The turbo itself was in Perfect! shape!!! Only the actuator for the VGT was dead :( Sloppy engineering.
And due to some restrictions here in denmark, spare parts to rebuild my turbo was not an option :(

And check DPF, and temp sensors in the exhaust while you're at it, mine were dead at the same time as the turbo, maybe overheating something. i don't know.
Hopefully i dont scare you with the dead turbo thing if it's only the MAF sensor! :)
Remember don't jump to the conclusion, test everything else first.
Maybe unplug the MAF sensor and try if acceleration has changed?
Vallunstein297
Posts: 7
Joined: 31 Oct 2020, 16:29

Re: C5 2.2HDi 170 is slow at acceleration

Post by Vallunstein297 »

mrpedersen38 wrote:
14 Jul 2021, 00:25
Air flow sensor is a good place to start but maybe your luck is as bad as mine.
I Have an 2.2 204hp model from 2012, my turbo died on me, and i had EXACTLY those symptomes.
on the 2.2 the Turbo is not vacuum controlled, but electronically. The mechanism from the servo to the (VGT) turbo itself was worn out and Very loose.

i could reach the turbo actuator arms from above the engine and feel they were very loose.
i changed the turbo with a brand new one, and the car ran perfectly ever since.

BUT check the mechanism controlling the VGT before jumping to conclusion!

They should NOT be loose or feel "sloopy" in the joints.
It's a common fault on the 2.2 turbo's from Mitsubishi/garret.

It could be a combination from the vibrations and heat from the motor jerking the mechanism to actuate the VGT in the turbo.
Mine were so bad i could slam the brakes and gas pedal at the same time and then the turbo would kick in! :D
The turbo itself was in Perfect! shape!!! Only the actuator for the VGT was dead :( Sloppy engineering.
And due to some restrictions here in denmark, spare parts to rebuild my turbo was not an option :(

And check DPF, and temp sensors in the exhaust while you're at it, mine were dead at the same time as the turbo, maybe overheating something. i don't know.
Hopefully i dont scare you with the dead turbo thing if it's only the MAF sensor! :)
Remember don't jump to the conclusion, test everything else first.
Maybe unplug the MAF sensor and try if acceleration has changed?
Hello and sorry for late response! :( I was a bit busy with things.
So anyways,I changed the Fuel Filter and nothing really happened. The car continued to struggle.
Tommorow I will be calling a guy in my town,and will see if I can arrenge a diagnostics with Lexia program.
Then,I can get a bit more exact details on my problems.
mrpedersen38
Posts: 19
Joined: 11 Dec 2019, 10:46
x 2

Re: C5 2.2HDi 170 is slow at acceleration

Post by mrpedersen38 »

Vallunstein297 wrote:
20 Jul 2021, 20:46

Hello and sorry for late response! :( I was a bit busy with things.
So anyways,I changed the Fuel Filter and nothing really happened. The car continued to struggle.
Tommorow I will be calling a guy in my town,and will see if I can arrenge a diagnostics with Lexia program.
Then,I can get a bit more exact details on my problems.
Lexia/diagbox didn't tell me that the turbo actuator died in the beginning (few symptoms) only when it died completely.
computers can only do that much sadly :(

And the maf sensor can still be bad eventhough the computer says its fine.
My brother recently had a C4 in acting really weird.
A new maf sensor fixed it, eventhough the old one read perfectly fine.
Vallunstein297
Posts: 7
Joined: 31 Oct 2020, 16:29

Re: C5 2.2HDi 170 is slow at acceleration

Post by Vallunstein297 »

mrpedersen38 wrote:
20 Jul 2021, 23:37
Vallunstein297 wrote:
20 Jul 2021, 20:46

Hello and sorry for late response! :( I was a bit busy with things.
So anyways,I changed the Fuel Filter and nothing really happened. The car continued to struggle.
Tommorow I will be calling a guy in my town,and will see if I can arrenge a diagnostics with Lexia program.
Then,I can get a bit more exact details on my problems.
Lexia/diagbox didn't tell me that the turbo actuator died in the beginning (few symptoms) only when it died completely.
computers can only do that much sadly :(

And the maf sensor can still be bad eventhough the computer says its fine.
My brother recently had a C4 in acting really weird.
A new maf sensor fixed it, eventhough the old one read perfectly fine.
Oh yeah! I know that. But i'm better at taking a shot with a Lexia diagnostic for now,rather than,start changing things and still not have the problem fixed. I will be posting if anything really comes up.