What can affect the MOT emissions on a Peugeot 405 Turbo Diesel?

Question

My car has failed the MOT. It has clean oil and a new oil and air filter but failed the MOT badly. Any ideas for what to look at next. It doesn't have a catalyst.

Answer 1

I had a diesel car that failed on emissions.I was told by a friendly mechanic to give it a good burn out.This involved driving in third as fast as you can to clean out the system.The car passed next day without costing me anything.

Answer 2

Hi

Regardless of any horror stories people may tell you, the most common cause for a diesel to fail on emissions is due to dirty injectors.

This is an easy and inexpensive fix as long as they are not too far gone, and the fix is as follows:-

Buy yourself a bottle of injector cleaner, pour it into the fuel tank on the basis of 1 bottle to a full tank so a little bit of simple maths is required here depending on where your fuel needle is!!

Once you have done this, get onto the nearest dual carriageway or fast road and give your car good old "Italian Tune Up", ie, rag the knackers off it in third gear up and down the road for a mile or two to clean out the injectors.

You may also want to treat the old girl to a new air filter just for the finishing touch if you feel so inclined.

Best of luck

Geordie

Answer 3

Worn piston rings.
Worn turbo oil seals.
Worn valve-stem seals.
Worn injectors.

My 1997 Rover 220SDi (turbo diesel) failed its first MOT (in 2000) on emissions and the garage's answer was to drive it hard up and down the road a few times to "blow the cobwebs out". It passed after this, so maybe that's all your car needs.

There are a lot of possibilities.
Find a local independent diesel-engine or Peugeot-Citroën service specialist.

Answer 4

Cleaned my diesel injectors by pulling the injector fuel pipe off of the fuel filter and sticking it into a bottle of injection cleaner...held the bottle while somebody else started the engine and watched the level in the bottle go down..stopped the engine just before the cleaner had all gone from the bottle...then replaced pipe on fuel filter which had also been changed...this worked on my 405 and garage actually recommended doing this but don't do it if you are not sure how...

Answer 5

if the engine is the xud 9 type 8 valve get injectors tested at lucas & overhauled if necessary. if 16 valve engine these block up inlet ports with carbon due to closed breather system. especially if used as a taixi & left ticking over on the rank for half an hour at a time. or run on chip fat oil. in both cases check valve clearances & peform compression & cylinder leakage test for eng condition

Answer 6

Try putting in some of this new optimax diesel stuff or some new type diesel, then before you take it into the mot give it a really good trashing to clear any deposits !!!

or get a new exhaust with cat?

Answer 7

You'll see the common thread here, it's chuck in some injector cleaner & give it a good hard thraping, right up to max revs, for a while. Common problem.

Answer 8

try your fuel filter you could also try a fuel additive to clean injectors,pump etc.