406 Diesel difficult to start in cold temperature.

jonnya · Post by **jonnya** » 24 Jan 2011, 11:58

Hi,

I have a 2003 Peugeot 406 HDI s Estate. Through the winter around 2 degrees temp or less the car is almost impossible to start. It will eventually start but probably on compression only...the battery nearly dies very time. When trying to start the glow plug light only comes on for a quarter of a second (if at all) and goes out v. quickly. Am guessing it is a glow plug issue or a relay issue. Or is it something else?

Winters nearly over but still need to sort it! Any ideas would be really appreciated.

Thanks,

jonnya.

spider · Post by **spider** » 24 Jan 2011, 12:33

A couple of seconds (for the light, not necessarily for the actual plug operation time) is normal at that temperature, see here > http://www.frenchcarforum.co.uk/forum/v ... hp?t=33672

I would suspect though that you have one or more down. It's worth replacing them anyway if in doubt as they are difficult to test in situ (due to odd issues like glowing in the middle, which will pass a current and resistance check in most cases)

The coolant temp sensor is likely to be OK as you`d notice other problems otherwise.

I'd say replace them as a matter of course then see what improvement you get.

jonnya · Post by **jonnya** » 24 Jan 2011, 17:38

Ok, thanks... Will start by changing plugs. I'm guessing you think the relay will be ok?

jonnya

spider · Post by **spider** » 24 Jan 2011, 18:09

The relay is usually OK to be honest. I've only ever had to change one that I can remember.

If you have an assistant you could check, attach a test light onto the glowplug or the relay feed to them and switch the ignition on, the test light should come on.

Use a meter ideally actually so you do not upset the resistance of the circuit.

The dashboard light and the time the plugs are supplied (including post heating but that would not stop it starting even if post heating had failed completely) are different.

jonnya · Post by **jonnya** » 24 Jan 2011, 18:20

Ok ...thats great....will go with that! Thanks Andy.

Post by **CitroJim** » 24 Jan 2011, 18:24

After extensively testing an HDI glowplug system, I can confirm that at 2 degrees they will barely come on at all before a start but will come on after the engine has started.

Also, an HDi in good fettle will start perfectly at -8 degrees with no glowplugs working at all. This is no guess or supposition, it was proved on an engine that had four very dead glowplugs in it. There were no symptoms to suggest they were all duff and they were examined only in an attempt to try and trace a cold running faults that in the end was not in any way glowplug related.

They come on after the engine has started (called post-heating), we believe, only to assist with keeping emissions in check.

I'd suggest that in your case, dead glowplugs are not the root cause of your problems.

Once running, does the engine run OK and during starting attempts and when initially running do you see any smoke? White smoke may suggest low compression leading to much of the fuel not burning. This would very much make the engine hard to start.

Also, on the predecessor XUD engine, which was very similar, the valve clearances were tightest when the engine was stone-cold. If the clearances were tight they could actually have negative clearance (and concomitant loss of compression) when the engine was very cold and this would lead to very difficult starting indeed but once started and warm the engine would run perfectly.

jonnya · Post by **jonnya** » 24 Jan 2011, 18:50

Yes it runs well after starting (although has fuel consumption issue since i had the car...only 44mpg with a light foot(still trying to establish cause )...initial idle period there is no white smoke.

From what you are saying in your post is that glow plugs do not assist the engine to start in any way?

jonnya

ps mpg issue could have been detached brake shoe in rear hand brake drum..which have been replaced...not convinced though....need more mileage to test

Post by **CitroJim** » 24 Jan 2011, 18:54

jonnya wrote: From what you are saying in your post is that glow plugs do not assist the engine to start in any way?

Yes, not at 2 degrees anyway. If you look at Andy's linked post, they do not pre-heat until it is very much colder than that.

It is odd it is so reluctant to start. Does it spin over rapidly on the starter or is it a bit sluggish?

jonnya · Post by **jonnya** » 24 Jan 2011, 19:19

Ok...starter motor a bit sluggish and battery needs replacing....would a heavy duty battery and newer starter motor make a difference....

Am assuming the engine just starts on compression alone(if that the right term) just by cranking engine over?

Post by **Peter.N.** » 24 Jan 2011, 21:57

That's probably got a lot to do with it. My recently acquired 406 Hdi started within a couple of seconds every morning during the snow but the starter does turn it over at a rate of knots, obviously the battery and starter need to be in good order when you are relying almost entirely on compression to start.

Peter

jonnya · Post by **jonnya** » 25 Jan 2011, 17:28

Ok will look at that. I have a hunch that could be it. Thanks for all your input...

Thanks again,
Jon

barrydoran · Post by **barrydoran** » 27 Jan 2011, 17:21

I concur with the inlet valve clearance diagnosis, having just gone through the exact same problem with a partner. Look for my threads on here.

The car was a pig to start, but would go all day once started and run fine, no smoke etc.

Starting weas a case of churning over and over until it caught. New glow plugs + battery + relay masde no difference.

Eventually got another car after garage gave up on it.

At my lesuire I scoured the internet and the "check the inlet valve clearances" advice seemed to be offered again and again, but rarely heeded.

On the partner, they were in fact negative, once re-shimmed the car started first turn of the key after a freezing night ( thick frost on windscreen). I was surprised to say the least.

Check the clearances, just to rule it out. Or at least get the compression checked as you will have low compression if the valves are being held open because the clearances are too small.

Barry.

spider · Post by **spider** » 27 Jan 2011, 18:11

Its because they are not easy for the inexperienced to adjust that's all as they are shim and bucket. To be fair they do not (or should not) go out much. I've never adjusted mine

and they are within tolerance (they were a year ago) at 180K, I've had it year and the previous owner had it for years and they never had them done either as they are a friend of mine.

It's mainly the N/A 1.7XUD that suffers with this although all the XUD's can suffer it if they overheat. The 1.7XUD is the only one that does not have a coolant exchanger fitted to the oil filter (go look at a 205D / Visa if in doubt)

Although I have not looked, I was under the impression DW10's were either screw / locknut or hydraulic for clearance adjustment...

jonnya · Post by **jonnya** » 27 Jan 2011, 19:43

The engine is ok to start through the summer (two tries and it starts) and have had someone jump start car when battery was flat ( in winter, was a tractor possibly 24v ..but it just jumped to life! Is it still possible that it could be valve clearances? (you issue with starting does sound very familiar though!

jonnya

Post by **Peter.N.** » 27 Jan 2011, 22:12

Your primary need is to get it turning over fast, if it turns slowly that would seem to indicate the the compression is good or at least certainly not very poor. Mine has done 190,000 miles and starts instantly because it has a good battery and starter and good low resistance wiring as well.

Peter