Power Loss On A 2001 406 Hdi 90 Estate

[hoodygoodwood 70 3 Cars]

I have just bought another Peugeot 406 HDi to replace the last one which was rear ended a couple of weeks ago . This one has driven fine till last night when it suddenly lost power badly while driving along at 30 mph , within 10 secs or so it cleared itself and was ok for a few mins then did it again . Starts and drives normally the rest of the time but when it plays up I am noticing some smoke from the exhaust which is not there before . Feels like its lost 80 % of its power and the engine will barely rev even in neutral . Will give the engine bay a good look over tonight - I am thinking a sensor may be going down or the turbo waste gate could stick open .Would the smoking be overfuelling or poor combustion .

Any ideas ?

[welshpug 1,657]

egr and maf issues are most common.

[Miles 331 1 Cars]

as above, if driven around town it will be caked up with gunge due to modern Derv's designed for long Motorway trips, Does the EML come on? I guess the 90's don't have the FAP system

[hoodygoodwood 70 3 Cars]

No lights come on when the problem occurs , it has only done it a couple of times so I will take it out for a spin and double check .Have had a read up on EGR valves after Welshpugs suggestion and that would be the no 1 culprit .Would it be worth refitting it after a clean or is it worth changing for new in case its faulty as well as coked up ?

[Anthony 1,003]

Just blank it off with a plate for a few quid off eBay - works perfectly, stops the intake being caked up with gunge, and usually you'll see better fuel economy (esp. if the EGR is leaking past).

 

That's what I've done on both my current and previous 306, which shares the same engine as the 406 HDi 90.

[welshpug 1,657]

took about 5 min to blank the egr on a 110 c5 hdi, inc making the blank from a bit of steel.

[hoodygoodwood 70 3 Cars]

Have bought a blanking plate off ebay , will fit it as soon as it arrives and see if it fixes the problem .

[steve@cornwall 100]

Brother in law had similar with his hdi engined ducato van. He was advised to change the afm sensor, then the egr, then the turbo, then the engine none of which worked.In the end it was sold for spares for a pittance.The guy who bought it plugged in his laptop thingamabobby when he viewed and the fault codes thrown up were many, including head gasket failure! (On the replacement engine with mostly the ancillaries from the original)

Turned out that replacing the injectors with a complete.set of known good ones sorted it. (It ha been fitted with a couple of the original injectors as the replacement engine had a couple of damaged one's)

 

(Edited because my damned kindle thinks it knows better than me which words I wish to use!)

Edited July 14, 2016 by steve@cornwall

[allye 530 3 Cars]

Just to throw in the mix low pressure pump as fpr can also do that. Although both would throw up fault codes.

[RossD 44]

Somebody who can decipher the live data and what is happening when the error occurs using Diagbox or Peugeot Planet will be able to pin the fault down in a matter of minutes. Don't bother guessing and playing the parts lottery.

[hoodygoodwood 70 3 Cars]

The 406 HDi is playing up even more now , have fitted a EGR blanking plate but it has not helped the problem . The loss of power is happening more often and it will only rev to about 3000 rpm in neutral but is so low on power that when driving it hardly wants to accelerate .If I open the bonnet and floor the accelerator the engine gets to 3000 rpm and sounds like its bouncing off a rev limiter , its pushing out black smoke from the exhaust but is also smoking from down the back of the engine which I had not seen before .

Engine starts ok , ticks over ok and does not overheat .

Will try to get it plugged into a diagnostic machine this weekend and have a look down the back of the engine .

[Miles 331 1 Cars]

Get onto 406 coupe forum, they have a list of member's who have Pug Planet

[hoodygoodwood 70 3 Cars]

If I leave the engine idling I can unplug the connector from the MAF sensor and the engine will tick over and rev normally - is that normal ?

I am running out of time as I have 3 weeks family holiday in this car coming up so I will take it up to Peugeot tomorrow and have them put it on their diagnostics .

New aftermarket MAF sensors are quite cheap on Ebay , I normally wouldn't touch them but might be useful to try a swap with a new one rather than an unknown used item .

[welshpug 1,657]

id get an used maf from a breaker sooner than trying cheap items.

[allanallen 528 2 Cars]

Does it drive better and rev over 3k with the MAF disconnected?

Have a good check round for boost leaks too, particularly the hose on the turbo outlet. Best to remove driver side wheel to access that.

 

I'm not familiar with 406s to be honest, do they have a DPF?

[welshpug 1,657]

the 90 won't have a dpf or dmf, or intercooler.

[hoodygoodwood 70 3 Cars]

The HDi 90's are quite simple , no DPF , intercooler or dual mass flywheel as Welshpug says .

Took it to a local garage to put it on the diagnostic tester , they checked it over and saw the smoke from the engine bay and said there was a crack in the induction setup and it would be best to fix that first . They offered to do a test with the smoke machine to find the leak but that would cost at least £75 so I decided to have a look for it myself .

By revving the engine while laying under the car I found the smoke was coming from the flexi joint in the exhaust system close to the turbo , there was also a 3mm dia hole in the weld at the flexi , put some heat wrap and a Jubilee clip round the hole as a temporary fix .

Will try to get a new MAF this week and try that and then go the diagnostic route next weekend .

[Paul_13 212 1 Cars]

It will run if you unplug the maf.

 

If it runs better your maf is screwed

[Alan_M 66 1 Cars]

I think others have had trouble with the cheap EBay MAFs. Try and get a good use one or genuine Siemens VDO (ECP on a sale weekend!).