406 running rough

Hi Folks,
I have an intermittent problem I hope you can help me with.
I own a Peugeot 406 2.0 litre twin cam 1998 model.
Every now and then about once a week the car runs rough and the engine
management light comes on. It usually happens when cruising at 60 or 70
mph but sometimes happens at different speeds. It feels as though all
four cylinders cut out for a second or so. The car also misfires. If I
stop during these 'rough' periods the engine refuses to tick over and cuts
out. I can get the management light to go out by accelerating if the fault
occurs whilst cruising. The fault is not consistent and can disappear for
a few weeks or reappear every other day.
Thanks in advance for your help.

 

Check your bobine......
When the car misfires it's usualy the ignition.
Was having a same kind of problem.

Greetz Aat

 

MAF sensor? If the warning light is coming on then it should show in the ECU
diagnostics.
I've got a 406 with the HPi (low emission 2.0L petrol) engine and had a lot
of trouble with this, although once it came on, the engine management light
usually stayed on. Mine was usually OK on steady cruising, but
misfired/hesitated a lot under acceleration - pulling out of junctions
became a nightmare.

 

I own a Peugeot 406 2.0 litre twin cam 1998 model.

Make that a MAP (manifold absolute pressure) sensor - about £35 from your
friendly Pug dealer - fit it yourself.

About to do mine on my 1.8 petrol.....

Adam H

 

Again, this sounds very much like a problem with the MAP sensor that I
had on my 1998 vintage 2.0 coupe a few weeks ago. Do you notice the
problem when cruising and the gradient changes slightly? You may also
find it load dependent. I tried for ages to correlate the symptoms
with what the car was doing and the correlation was most confusing
till it dawned on me to think in terms of inlet manifold vacuum.

My advice is to pay and get the code read out of the computer and if
it is a MAP sensor then replace it yourself. I have posted an article
on my similar issue a week ago. Changing the sensor cost <£40 and took
<30 mins.

Then again, it may be plugs, coil etc, but I doubt that these would
register with the management computer.

 

Again, this sounds very much like a problem with the MAP sensor that I
had on my 1998 vintage 2.0 coupe a few weeks ago. Do you notice the
problem when cruising and the gradient changes slightly? You may also
find it load dependent. I tried for ages to correlate the symptoms
with what the car was doing and the correlation was most confusing
till it dawned on me to think in terms of inlet manifold vacuum.

My advice is to pay and get the code read out of the computer and if
it is a MAP sensor then replace it yourself. I have posted an article
on my similar issue a week ago. Changing the sensor cost <£40 and took
<30 mins.

Then again, it may be plugs, coil etc, but I doubt that these would
register with the management computer.

 

First thanks for all advice.
Been working away the last couple of days and it just so happened a mate
of a mate has a injection/ignition business.
Having talked to the guru he reckons that it is the spark generator or
words to that effect. He also asked if I had changed the plugs. I have
in fact changed the plugs shortly before I had this problem. I took out
twin electrode plugs and replaced them with single electrode plugs as
recommended by the NGK bible. In desperation I have put the old plugs
back in just to see what, if anything happens. Will post again with
results.
Just of interest my car has no leads or distributor just what looks like
cows udders from a plastic plate. The guru also stated that the MAP
sensor would not give me the faults I have. In reply to Mike I can get
the car to run smoothly by accelerating, this also puts the engine
management light out. But as soon as I try to cruise it misfires again.
Was the worst it's been on the journey home tonight so I am hoping the
plugs cures the problem!
Fingers crossed.
Thanks again.
Robbiemac

 

Hi All,

I have a very similar problem. I have a 1997 2.0 406 Auto and the problem
is very similar in terms of the "MAP" light coming on and the car cutting
out (orange light with engine - i think!)

The car mainly cuts out when you are sitting in traffic or have constantly
stop and started the car and then sitting in traffic. When the car is
moving on the moterway it is fine....

Hope this make sense - Any ideas/sugestions/hints on resolving problem
welcome.

Thanks in advance...
nicrnp

 

As I understand it the engine management system stores any error codes
- even when the watning light does not come on. We had odd problems
once and the diagnostics were able to read codes, they made the
necessary fixes (in that case a temperature sensor as I recall) and
the problem disappeared.

On the other hand I have worked miracles simply by changing spark
plugs - not in a Peugeot but in things like ride-on mowers. The most
remarkable experience I had was a pump with a Honda motor. Suddenly,
while apparently running OK, it did not have quite enough herbs to get
the water to the top of the hill. It was simply a faulty spark plug!

 

I have had the same problem with mine. Had the 'puter read and it came up
with nothing! The problem is till here and still intermittent, not occuring
at all when the guy came to read it so no suggestions from him.

 

Hi All,

Had a diagnostics check done by Peugeot today - needs the MAP sensor
replacing and also the oxygen sensor.

Hope this helps? All I need to work out now is how to change these sensors
- any hints/tips?

Cheers

 

Well a quick update...
Changed plugs and car is a whole let better. Done about five hundred
miles and it only misfired a couple of times and only once did engine
management light come on.
Moral of story is make sure the correct plugs are fitted and also bear in
mind the guru's quote that my particular model is fussy about the type and
make of plugs fitted. I would definitely steer clear of single electrode
plugs.
Anyone know of an internet supplier of Equem plugs?
Problem not solved altogether but much much better.
Thanks again for all your input.