1.5D cold starting diagnosis

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gav76
Posts: 4
Joined: 23 Dec 2003, 18:43

1.5D cold starting diagnosis

Post by gav76 » 23 Dec 2003, 18:49

I've just had my 106 mk1 1.5D serviced at 80k and the poor starting in cold weather has been attributed to "tight valve clearances" by the Peugeot mechanic.
What does this mean and how does it occur?
Is this anything to do with tappets?
Is this a common occurence with relatively low mileage diesels?
Is there anything I can do to prevent a hefty bill for 3.5 hrs of the mechanics time to fix it? I've already tried fuel additives, oil additives and an oil flush, but made no difference.

Dave Burns
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Joined: 14 May 2001, 05:30
x 2

Post by Dave Burns » 23 Dec 2003, 19:37

Hmm...could be an attempt to sting you for some dosh, you must make sure that what he is on about is the actual fault, if not allready done, a compression test or better still a leakdown test will point to any such problems, get it done somewhere else though, shouldn't be the problem at that mileage but its not unheard of.
First things to look for are correct operation of the glow plugs, and the possibility of air getting into the injection pump, these are very much more likely causes of starting problems than the valve clearances.
If the valve clearances are too tight the valves could be left open slightly when they should be closed, this can happen due to wear of the valve and valve seat and also the camshaft bearings.
Dave

gav76
Posts: 4
Joined: 23 Dec 2003, 18:43

Post by gav76 » 23 Dec 2003, 22:24

I've done a resistance test on the glow plugs and they're all exactly the same resistance. So I don't think it's them.
So how would I check if it was air into the injection pump?
Also, I've noticed a slight 'lumpiness' in the idle even when warm. What do you attribute this to?

wheeler
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Joined: 21 Sep 2002, 19:07
x 78

Post by wheeler » 24 Dec 2003, 00:28

this is quite a common problem on saxos & 106's with this engine even at lower milages than this,it only seems to affect the inlet valves,usually though its more of a hot starting problem,the head will need to be re-schimed.there is a special tool available to let you change the schims without removing the camshaft.

Dave Burns
Posts: 1916
Joined: 14 May 2001, 05:30
x 2

Post by Dave Burns » 24 Dec 2003, 02:05

Yeah the lumpy idle when warm makes it sound like the original dignosis is right, turn it over by hand if you can and see if any cylinders loose their compo easily, listen for the hiss of escaping air in the intake.
If it is the valves it wants doing soon before they are burnt and pitted to buggery.
Dave

DLM
Posts: 524
Joined: 13 Aug 2001, 03:01

Post by DLM » 24 Dec 2003, 05:47

Took me a while to realise "schims" = shims. And there I was thinking you couldn't possibly "schim" a head while still in place (I was thinking "skim")!

gav76
Posts: 4
Joined: 23 Dec 2003, 18:43

Post by gav76 » 24 Dec 2003, 16:55

Definatley not a *hot* starting problem. Only when cold <5C and has been left for >12hrs.
'wheeler' - I don't understand - where do the shims go?
So to test the compression pressure, does the compression tester fit into the glow plug hole, or into the injector hole?
What should the maximum pressure be when I crank the engine by hand?

wheeler
Posts: 3766
Joined: 21 Sep 2002, 19:07
x 78

Post by wheeler » 24 Dec 2003, 17:30

whoops sorry,i thought thats how shim was spelt[:I]
the shims sit directly under the camshaft on top of the 'buckets' which sit on top of the valves,they are about the size of an old 10p coin but come in various thicknesses,this is so it can act like a kind of spacer between the camshaft & the valve (therefore adjusting the clearance).
it depends on your compession tester kit wether you use the glowplug or injector hole but normaly the glowplug hole in this case as its easier.
im not sure off hand what the reading should be.

gav76
Posts: 4
Joined: 23 Dec 2003, 18:43

Post by gav76 » 24 Dec 2003, 17:36

Cheers wheeler - so...
[thinking out loud]
If the shim sits between the 'buckets' and the cam, and the valve is not closing properly, does this mean I need thinner shims? If so, how come the shims in it at the moment have suddenly got too thick??? Doesn't seem to make sense to me!
[/thinking out loud]

Dave Burns
Posts: 1916
Joined: 14 May 2001, 05:30
x 2

Post by Dave Burns » 24 Dec 2003, 19:48

Take the rocker cover off and with a set of feeler gauges see if you can get the correct clearance blade between the back of the camshaft lobes and the shims, or if any blade at all will go between, if you can get even a thinner one between then the problem isn't likely to be propped open valves.
You wont be able to turn the engine by hand to generate any meaningfull pressure, I suggested turning by hand (using a socket on the crank bolt) merely as a simple test for the ability of the cylinders to generate compression, the air in the cylinders will escape naturaly as the pistons rise, its the speed at which it escapes that is the pointer.
Dave

mgoodlad
Posts: 90
Joined: 19 Sep 2002, 22:17

Post by mgoodlad » 05 Jan 2004, 18:06

I have tended to just change all 4 glow plugs to eliminate this as a possibility - it doesn't cost too much (well £6ish each) but then you know you have 4 good ones - keep the old ones for spares.
But at least pull one or two out for a look - although the resistance could be okay the ends could be pitted or coated and not doing their job properly. I have heard poor spray patterns on the injectors can damage them.
I also guess you have a strong battery? I had a Landrover Discovery with a poorer battery which had similar symtoms and a new battery sorted it.
Michael
1996 306 TD 62k miles
1996 106 1.5d 82k miles

mgoodlad
Posts: 90
Joined: 19 Sep 2002, 22:17

Post by mgoodlad » 05 Jan 2004, 18:09

PS my current 82k mile mk 1 1.5d 106 starts fine in the cold, and I had another identical one from new until 90k miles and that never had any problems like this (apart from a glow plug giving up).
So I have not found it to be common, unless any other owners out there.
Michael