Still need some expert help

This is the Forum for all your Peugeot Technical Questions, Problems or Advice.

Moderator: RichardW

Lawrence1973
Posts: 100
Joined: 16 Feb 2009, 23:19

Still need some expert help

Post by Lawrence1973 » 11 May 2009, 20:51

:(
Hello All,
Still having trouble diagnosing my peugeot 406 td fault (see topic Point of no return)
I have eliminated the injector Needle lift sensor, timing belt positioning, injectors and many more but still the engine runs badly- as if 3 cylinders firing. I noticed that the exhaust smoke is fairly white but I am wondering if this is more to do with the engine being cold.

I am pretty sure I have eliminated air leaks......one other option is the TDC sensor but I am not sure how to test this sensor? anyone have any suggestions?

Cheers

User avatar
CitroJim
A very naughty boy
Posts: 41564
Joined: 30 Apr 2005, 23:33
x 1033

Post by CitroJim » 11 May 2009, 21:21

Hi Lawrence,

Didn't realise you're not that far away from me in Hertfordshire :wink:

Take a spin up here and we could pop the car on the Lexia, that should help shed some light.

In the meantime, have a look at this thread as it describes a similar sort of issue really and will tell you how to test the TDC sensor...

Lawrence1973
Posts: 100
Joined: 16 Feb 2009, 23:19

Post by Lawrence1973 » 11 May 2009, 22:24

Hello Jim,
I thought you'd abandoned me! I asked about a chat on the phone because I thought I am probably not getting everything down in text!

I would be more than happy to stick it on the machine but it won't drive like it, it's really unhappy! I had a look at the the other threads (thank you). This seems slightly different. The engine starts fine after the heater plugs cut out but it shakes about on its mountings pretty badly. Also the problem remains regardless of the revs.

Any common air leak points to check?

Can you give me some more pointers as to where the wiring is for the TDC sensor? I can only see an earth bolt down there.

Cheers

Lawrence1973
Posts: 100
Joined: 16 Feb 2009, 23:19

Post by Lawrence1973 » 11 May 2009, 22:27

Oh yes,

I'm near Berkhamstead :wink:

Lawrence1973
Posts: 100
Joined: 16 Feb 2009, 23:19

Post by Lawrence1973 » 13 May 2009, 11:39

I am even more confused now!

I have disconnected the needle lift sensor plug and it didn't change the running at all. BUT I also cracked the union bolt on the injector to the right of the needle lift injector and that didn't change the running either!

The tacho works fine incidentally......

Any thoughts?

User avatar
CitroJim
A very naughty boy
Posts: 41564
Joined: 30 Apr 2005, 23:33
x 1033

Post by CitroJim » 14 May 2009, 11:07

Hi Lawrence,

Sorry for the delay in responding :oops: I've been thinking about this.

On the face of it, one of your injectors does look a bit suspect. When you had them out, did you replace the firewashers? They're the little domed washers that sit between the end ofthe injector and the cylinder head. They must be replaced whenever the injectors are disturbed and must be installed right way up with the convex face upwards. If they're missong or upside down they can affect the injector spray pattern.

White smoke indicates unburned fuel whereas a bad injector will produce black smoke. While smoke can also indicate low compression on one cylinder, low enough to not be able to fire the fuel charge.

It will be worth having the injectors out and stripping them and giving them a clean, especially their internal passages with an air-line, as I recall you said something earlier about black speks you saw when you popped the unions off.

If you do strip the injectors, be careful not to mix up bits from one to another so do them individually. Be extra careful of the needle lift sensor injector as it is dead easy to damage it when pulling this injector apart.

With a badly running engine, it will be very difficult to tell any difference in running when disconnecting the needle lift sensor.

If that does not go some way to resolving, I'll happily take a run down to see you as Berkhamstead is not far off really. Not sure when though, I'm pretty busy for the foreseeable...

Lawrence1973
Posts: 100
Joined: 16 Feb 2009, 23:19

Post by Lawrence1973 » 14 May 2009, 22:14

That's very good of you, thanks.

Useful info thank you. I did have a play with the injectors - all clean apart from the needles which I managed to clean gently using a hand lens and soft cloth. They're not as complicated as I thought. Fire washers were all replaced and right way up.

I am really starting to wonder if one of the rings has gone......so it would be the end of the road there.

It's all quite sad really, the car cost £800 with quite a bit of S history. Having replaced the bosch pump and all being well I was thrilled but then it all goes wrong!
I really am a fan of these engines and always found the old Talbot 1.9 lump a real work horse( having owned 309s and 405s before) I didn't think I could go wrong. I was even looking forward to burning a bit of veg oil as the bosch pump would allow.

I will put the violin away now :lol:

Thanks for all your help sir

Lawrence

Lawrence1973
Posts: 100
Joined: 16 Feb 2009, 23:19

a visit

Post by Lawrence1973 » 26 May 2009, 11:16

If you're still out there Jim, I wondered if we could arrange for you to pay a visit some time to see if an expert could diagnose the problem.......this before I throw in the towel for good!

A mate of mine wondered if it is the head gasket after all. One thing we noticed - I wondered if the stop solenoid was playing up and disconnected it and tried cranking. The engine obviously turned over for a longer period this time and it sounded quite uneven.

There is a bit of an oily ressidue in the expansion bottle but there are no other signs apart from that. Maybe it's a break in the gasket between chambers and leaking compression that way.

If it turned out to be the head gasket, I'd be tempted to have a go as touchwood, after that, I might have a good car for a while longer. I did the head on the 405

User avatar
CitroJim
A very naughty boy
Posts: 41564
Joined: 30 Apr 2005, 23:33
x 1033

Post by CitroJim » 27 May 2009, 12:50

Hi Lawrence,

Yes, I'm still here and I've just seen your email. Sorry for my absence but I've been up to my ears in all sorts of things both professional and personal that have conspired to keep me away from the forums and cars in general. I'll explain all in my blog shortly..

I'm busy this weekend, taking a run on Saturday to the West Country for an overdue visit to the family down there and then on Sunday it's the big one for my V6; the engine will be lifted back in. Next weekend will present an opportunity to come and see you if that is good with you...

I was thinking that the compressions may be an issue in all this. Before going ahead and lifting the head, a compression test will be a good idea. Diesel compression testers are available and they will tell you most of the story but they're expensive although they might be hireable... A petrol engine compression tester will not do the job.

Professionals use a leakdown tester to check the integrity of a diesel engine. Basically, these pressurise the cylinder under test and you record the time the cylinder will hold a given pressure.

Something else to check is the valve clearances. Just occasionally they close up and reduce compression.

It is also possible, although rare, that a glowplug is responsible for a compression leak.