Valve stem oil seals

[JulesMartin]

Hi, I'm getting a puff of blue smoke on start up which quickly disappears and doesn't reappear on hot restarts only when cold. Also the engine is lumpy when on cold start which again stops within a minute. I'm thinking that this is valve stem oil seals which is backed up by the fact that I found a packet of them in the bits and bobs returned to me after the head was skimmed. has anybody attempted this with the head still on? I have done it on older petrol engines using TDC to keep the valves in place. Any help as always greatly appreciated

[maxi_77]

The lumpy running on start up is likely to be a reaction to little use. When we bought our present Bongo it was very lumpy and would often cut out. We gave it the Italian tune up to beat all by motorway driving all the way from the Algarve to Scotland. Now idles like a dream on starting

[JulesMartin]

it could be. it is pretty much my daily vehicle of choice but it doesn't get to stretch its legs at all, may be I'll give it a bit of wellie up the road tomorrow. Good thinking thanks for that

[JulesMartin]

Hi guys, sorry for the long delay. My son blew up his VW camper and has been using my Bongo while we have been sourcing and installing a replacement engine on his. I have the Bongo back and I'm back to using it on a pretty regular basis and note that the smoke on cold start up and very lumpy idle is getting worse or seems worse since getting it back. I can leave it all day at work and on start up to come home virtually no smoke at all but in the mornings it's getting a bit embarrassing reversing off the drive through a cloud of smoke! Odd thing is it clears within about 30 seconds. when I start it, it will start eagerly enough but idles really lumpy then within a minute it picks up and settles to its usual idle. Not the smoothest but it never has been. I'll give the glow plugs a check over maybe one has gone on the blink. the MOT picked up a fuel leak from the injection pump so I'll need to do that again but I don't think that is the answer. any thoughts would be appreciated

[Bongolia]

Bit late I know but...
Valve seals letting go can usually be seen after heavy engine braking and then hard acceleration producing smoke.
Unburnt fuel collecting in the bores after a long stand would give erratic initial firing and smoke at start up.
I would be thinking of injector/s letting by when stood maybe.