Engine noise - C4 Picasso (B78)

[danlat1415]

I've started to hear a chugging noise on my Citroen C4 Picasso (diesel, automatic).
It's not all the time, but I can hear it when setting off from some junctions and going up hills.

It's not the standard engine tick over, but more of a deeper struggling, "ba, ba, ba, ba, ba, ba"
The car also doesn't feel as responsive when I put my foot down as it used to.

I've managed to catch the noise on my dashcam when I was going up a small hill.

There are NO warning lights or anything shown on the car's dash/display.

I've got a diagbox, but for some reason it's now decided to say the engine ECU isn't recognised, no matter what version I run, or what firmware is on the device.
(It previously worked fine).

When I read the fault codes previously (about 3 months ago) it gave P0272 which is a fault on the 4th cylinder (presume injector).

Since then, I've only been using premium diesel and I ran Wynn's Gold Diesel additive 3 times (one in every 3 - 4 fill ups) to see if that clear any build up.



I'm reluctant to go to Citroen only to pay for them just do a diagnostic, if I can at least have an idea before I go.

I'm guessing it could be injector, as that's the only fault that caused concern on last check. It seems to match the symptoms to.

Anyone have any advice or alternative suggestions for possible cause?


I know injector replacement isn't cheap - so I'm hoping it's not that.
Is £300-500 realistic, or am I way off?

My VIN is VF7**************[VIN obfuscated, can be read by forum staff]

Thanks

[danlat1415]

I'm going to start by replacing the fuel filter to see if this resolves it.

It was only changed about 2500-3000 miles ago.
It was a cheap one off eBay - so could be any quality....

I've also run 3 fuel additive cycles every 3 full tanks so that could have stirred up any gunk or dirt that can't be dissolved and now moved them though lines to get blocked in the filter - clogging it up a lot sooner.


I'll pick up a decent replacement from EuroCarParts and see how I get on.
I hope it sorts it because the car is really sluggish and struggles at times.

[GiveMeABreak]

Personally speaking, ^ they don’t have a good reputation.

But your injectors price new (Siemens) is £447 and a Continental exchange is £355. Inc. VAT from Citroen.

The part number for the fuel filter is: 9809721080

[myglaren]

My engine was leaping around in a very worrying fashion.
The mechanic I used, a trusted Citroen specialist, admitted he had no idea why and consulted the main dealer who claimed it was the DMF.
So, new DMF and clutch and no improvement.

I sent the injectors to a local diesel specialist who cleaned them and tested them, one had gone bad and was refurbished. All came in at under £150 and the engine was as smooth and quiet as a new one after that.
That would be around five years ago and it still runs as smooth and quiet of any of its type and is on approx 136,000 miles now.

[danlat1415]

**UPDATE**

I changed the fuel filter to a MANN FILTER and this fully resolved the issue.

Either I had a cheap/fake filter in previously, had a bad batch of fuel, or the recent fuel additives I'd put in stirred up crud - but the filter was quite bad and even swoppen (internal filter part).

It has only been on my car for 2000 miles. (I had written the mileage in marker pen on the canister).

The filter I had before was a cheap filter off eBay where you even get the top section which you normally remove and keep with the car.
(The screws on my previous, previous one had rounded off - so I needed the top section too).
I've now got a replacement top section from salvage and new filter from a retail store.


I definitely don't recommend buying cheap on eBay - you can never trust what you get. Especially with so many fake items out there that are poor quality counterfeit.