2.5 TDI Cold start issues

[neilA4]

Hi i'm getting blue smoke from a cold startup, but clears after 10 seconds, also It can take a while to start when it's cold outside. ie +4deg. When it does start it is very lumpy for a few seconds, like running on 4 cylinders but only for a few seconds?

Also getting a top end rattle which dissapears when engine has run for a while, although this seems to be getting better.

Starts fine when the engine is warm! no smoke no rattle fires up on first urn of the starter!

Any ideas? Engine is a 2.5 tdi AKE with 190,000 miles

Cheers.

 

[Mike B]

Are the glowplugs OK?

 

[neilA4]

how do you check glowplugs? the plug light comes on and goes off, bit slower to go off when cold.

ta

 

[Mike B]

That sounds normal same as mine 04 2.5Tdi Q but I think you can check the current which gives their glow.Otherwise maybe the coolant temp sensor but that would show on VAGCOM

 

[quattrojames]

Fuel pump timing, and air leaks in the return pipes from each injector are the only other two possibles really.

 

[neilA4]

Well have checked fuel pump timing and it is well in spec.
Injectors are fine also. Only fault code is for a engine mount.

So, got some bargain denso glow plugs from ebay £23 delivered for all 6!

Took ones on left bank out, they were newish ngk and came out easily.

The ones on the right bank were very old and I had to turn very carefully with lots of wd and loosen/retighten etc.

Also found that 2 of the leads were loose and not pressed on properly!! Just need a cold morning to test now.

Will change the oil retention valves under oil filter housing and see if that sorts the occasional tapping. Cams look ok through the fill hole, no grooves but do have wear marks in the surface finish.

doees the cat have to fully come off to change the retention valves?

ta

 

[ADC74]

Have you got a link to those 'glow plugs' on the bay ?
£23 sounds well cheap, every set I've looked at have been @ £50 - £60

Were they 'Denso' or 'Delphi' ?

 

[neilA4]

delphi,

GLOW PLUG DELPHI HDS374 AUDI VW SKODA SUPERB 2.5 TDI 3.0 A4 A6 A8 PASSAT T4 | eBay

offer him £3.50 per plug works out at £23.20 for 6 delivered (only one delivery charge)

car starts first turn of the engine now, seems to run smoother. One of the old plugs came out in 2 peices so may have been getting a bit of compression loss?

 

[haytch75]

Did this solve the smoke too mate?

 

[DAZ1985]

I run mine on optimax as I thought this would help

This time round I used normal shell deisel and millers ecomax, it's been better for less smoke on start up but I need run another tank through yet

Maybe worth a punt for £10 a bottle (treats 10 50l fills) £1 a tank, which I'll probably do once a month, plus it's cheaper to do that over optimax derv

 

[neilA4]

has not smoked on startup since, engine runs so much better from cold.

I just chuck in asda diesel, £1.36 round here

 

[DAZ1985]

Got the link to these glow plugs mate?

 

[neilA4]

Got the link to these glow plugs mate?

look in post no8

 

[quattrojames]

These are probably made by the very same people who make the oem ones, my only concerns would be they're more prone to snapping when the time comes to take them out

 

[ADC74]

Well I've just ordered a set, bit of a bargain for just over £20.
I've got no evidence in the service history of mine ever being changed so I guess I'll worry about trying to get them out in another 100k.

 

[neilA4]

I put copper grease on threads before fitting. Just be very carefull removing the old ones