Valve replacement 1.6td

[tommin]

Hi all, winter is finally over so I dug the van out and decided to see to the engine issue I have mentioned in the past (smokey).

Today I started from scratch, cam cover off, put engine to tic for the umpteenth time (but this time using the right procedure) I was guilty of trying to rotate via either the cam or the pump before Anyhow with cam lock on, pump pinned and crank at tdc, I went ahead and put the pump timing in order, found the pump was 1.2mm (this is why crank should be used, as the other way put tension on the belt in the wrong places) as stated GUILTY. I reset pump to 1.0 and closed everything and the old girl fired up no problem.

The smoke issue is definitely better, very little on tick over, but increases with throttle use, hazy blue which is still a problem. I read somewhere that by using a long screwdriver or similar you can test how your valves are working. You connect the metal end to the first injector and place your ear on the handle and with engine running can hear the injectors squirting and valves opening. You do this on all injectors and you can find out if there is a different sound somewhere along the line. I did this today and yes I could hear it all, and on number four could hear a totally different sound, the only way I can describe it is, like a jack hammer in the distance, a distinct popping or knocking sound.

So I think this may be a valve which one on number four am not sure, but with that blue haze I have been getting, could mean exhaust valve letting unburnt fuel through. I welcome any thoughts on this before I take the plunge and open it up.

Regards
Tom

[Aidan]

might it be the injector rather than the valves? easy enough to swap an injector and see if the noise/smoke is still there
btw I don't know anything about diesels

[phil_b]

Hi, unburnt or poorly burnt diesel usually shows up as white smoke not blue, if its blue that would suggest oil is getting into the combustion cycle somehow. This could be coming from worn piston rings, turbo oil seals or valve guide seals, another possibility is that the engine breather is blowing excessive oil mist into the inlet pipe, but that is usually indicative of problems elsewhere ie worn piston rings or malfunctioning oil separator (top of rocker cover).

Its fairly easy to disconnect engine breather at the inlet stub and vent into a temporary container, remember to plug the inlet stub, and see if the problem persists. This also allows you to see the amount and colour if any of the vapours from the breather pipe. Before pulling the head off it's probably also worth taking a look at the turbo by removing inlet pipe (a bit awkward with engine mount) and exhaust outlet and look for signs of excessive oil, oil mist on the inlet is ok but exhaust side should be dry.

How bad is the smoke and how much oil are you using?

[tommin]

Hi both and thanks for prompt replies and advice.

Aidan reference the injectors, they were pulled stripped and cleaned, but will take on your advice and try a swap around to see if it persists

Phil, I understand now, white + unburnt, blueish + oil. I will give your methods a try also, but am a little unsure which pipe is which. I believe the engine breather is the one on the cam cover going down to inlet manifold, am I right? I have taken it off with engine running and smoke also comes out from cam cover..... I have checked turbo pipes but they seemed acceptable just a little haze on the inside of one of them, not sure now which though?

Oil use, well not really sure, probably a litre every 500km at the moment. The smoke itself on tick over is barely visible, considering her age and km over 500 thou. It is on accelerating it gets bad, and leaves a trail of blue haze down the road !!!!! I can say, before our little issue with a leaking pump, the motor didn't smoke at all except when pushing 65-70 on a hill? We had the pump swapped out, was fine for a while then it all went wayward, BoD and downhill from there.

[phil_b]

Yes, breather is the one you identified going from the cam cover.

Your oil consumption is very high and smoke from the cam breather hole isn't a good sign, as it could indicate excessive blow past the rings, especially if the smoke smells like exhaust fumes. Maybe the next step would be to do a compression test.

I've recently had a similar issue on my 1.9td, high oil consumption, smoke from the breather hole and very oily smelling exhaust fumes although funnily virtually no blue smoke at least not visible when driving in daylight, but could be seen in headlights of following cars at night if they were close. That turned out to be excessively worn piston rings (end gap approx 4mm compared with a wear limit of about 1.2mm and thinned so much its a miracle they hadn't snapped), this was on an engine that had done approx 300,000km.

Maybe its the pushing 65 to 70 on a hill has done it

[tommin]

Managed to do a little video, hopefully it can show some of the smoke issue am having. I reset timing prior to this to 1.02. New fuel and oil filter. Injectors stripped and cleaned yet here we are.

http://youtu.be/AsEXQcZT6-Q" onclick="window.open(this.href);return false;

[phil_b]

That engine breather smoke looks pretty bad to me, although I would make sure the engine has been run good and hot in case its just condensation evaporating from not being not used over the winter. If it's just as bad or worse after a good run I don't think adjusting timing or fuelling will have any effect as its indicative of excessive engine wear ie bore/piston/rings. Not sure if any there are other possible causes headgasket?? but hopefully someone else will be able to add their advice/comment.

[tommin]

Thanks all for the input. I have now put this down for the summer 'to do project' I will take the head off and see what is happening from there. I am pretty fed up at the moment, thought it would be something a little more easier to rectify but to be honest always had that gut feeling it was something a little more, have to expect it with over half million km on the clock I am not yet ready to give up on the old girl, just yet!

I have a spare engine in the store, not worth swapping but great to practice on. I will up date in due course with pictures and videos.

Regards
Tom