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TimArnold

Member

Registered: 2024-08-10

Posts: 4

Fluctuating power and puffs of black smoke

Hi and Hello
Looking for any suggestions, 2008 Dispatch with 1.6 HDI

Mainly at just over 50Mph and moderate load the power fluctuates (only just noticeable) with a puff of black smoke every 2-3 seconds. Boost control valve replaced (boost value low) made no difference, EGR valve replaced, less noticeable but still smoking. No faults recorded, some fluctuation in live values related to EGR valve hence replacement. Head gasket failed and was replaced twice (first replacement failed after 8 Months)problem started immediately after 2nd replacement (head tested and skimmed both times)

Garage is an independent Peugeot Citroen specialist, they seem knowledgeable and trustworthy (2nd Head gasket totally FOC as they give 12 month warranty with no quibbles) but with no fault codes they are at a loss.

After 1st head gasket replacement gained 2-3 MPG, could the increased compression from 2 skims be related?

Any Ideas Please TIA

Tim Arnold
Frustrated Dispatch Owner

tee_cee

Member

Registered: 2016-03-18

Posts: 617

Re: Fluctuating power and puffs of black smoke

Does the van have a FAP exhaust?

TimArnold

Member

Registered: 2024-08-10

Posts: 4

Re: Fluctuating power and puffs of black smoke

Thanks for the quick reply. FAP Exhaust ? AFAIK its whatever it had fitted from new. Pretty sure it doesn't, I think the guys I have been taking it to would be aware of that

AlvyLad

Member

Registered: 2021-06-11

Posts: 473

Re: Fluctuating power and puffs of black smoke

Interesting no error codes, I would've guessed leaky turbo, but it would show on diagnostics...
Could be few other issues, normally they all would be showing errors.

One last thing to check is to do leak-off test, in case some of the injections misbehaving

TimArnold

Member

Registered: 2024-08-10

Posts: 4

Re: Fluctuating power and puffs of black smoke

Would this be the same as the test for a Freelander, remove leak off pipes and turn ignition on, check no diesel is escaping or is it more involved. When I had this with a Freelander it was difficult to start and had low fuel pressure fault. I assume they would have been removed to skim the head so if they need to be removed it should be reasonably easy

Would this be a good investment https://tools4car.co.uk/product/lexia-3/

Last edited by TimArnold (2024-08-10 19:40:07)

AlvyLad

Member

Registered: 2021-06-11

Posts: 473

Re: Fluctuating power and puffs of black smoke

Would this be the same as the test for a Freelander, remove leak off pipes and turn ignition on, check no diesel is escaping or is it more involved. When I had this with a Freelander it was difficult to start and had low fuel pressure fault. I assume they would have been removed to skim the head so if they need to be removed it should be reasonably easy

Would this be a good investment https://tools4car.co.uk/product/lexia-3/

Literally injector return pipes connected to x4 bottles, 10-15 min will tell you if something isn't performing as it should.

Lexia3 is a good thing, but it requires DiagBox, that's significant pain in the backside on it's own, however the "savings" I've made taking my car to all sorts of mechanics for diagnostics would've paid for itself tenfold.

Your "mysterious" loss of power should've produced some sort off errors, if your garage is decent, surely they had it tested. so, you getting one might be just getting it, not curing or even answering what's wrong.

I'm still guestimating to 1- turbo leaky; 2 something not 100% with injection, but both would've produced errors ... that doesn't make much sense, unfortunately

TimArnold

Member

Registered: 2024-08-10

Posts: 4

Re: Fluctuating power and puffs of black smoke

I feel its injector related. with the pipework stripped down there is always a risk of contamination, as for the lack of error codes most errors need to persist for a short period before being recorded to allow the vehicle to operate in the real world, each dip in power probably lasts for less than 1 second. i will try the leak off test then may invest in a recon injector and swap out one at a time. is there any documentation anywhere that describes the parameters that generate fault codes?

AlvyLad

Member

Registered: 2021-06-11

Posts: 473

Re: Fluctuating power and puffs of black smoke

https://www.peugeotforums.com/posts/2382035/

tee_cee

Member

Registered: 2016-03-18

Posts: 617

Re: Fluctuating power and puffs of black smoke

Lexia can tell you the rpm as each cylinder fires, which could isolate the problem.