miketomcat Posted May 3 Author Share Posted May 3 40 minutes ago, Peaklander said: Would a compression test help before delving into parts exchange? It drives and goes exactly as I expect, it doesn't seem to be over pressuring the coolant or crank case though I will double check at the weekend. 33 minutes ago, TSD said: Try cranking it first with the injector pipes loosened, to make sure the fuel system is fully primed? If there's some sort of micro-leak draining the fuel, that should at least make it clear itself noticeably quicker. That probably wouldn't account for the grey smoke though. Is it smoke or steam? (I have always found it hard to be sure.) Compression tester is here if you want it. Not sure if it's smoke or steam, I may have had a lose hose clip so an water loss is unconfirmed. Mike Quote Link to comment Share on other sites More sharing options...
TSD Posted May 3 Share Posted May 3 It occurred to me you might see how much condensation the exhaust produces on a bit of glass or metal? Normally I'd imagine that varies too much from day to day to be any sort of guide, but you have an identical engine in the same place you can try at the same time. Just a random idea, might be a complete waste of time (like many of my ideas), but would only take 5 minutes to try. 1 Quote Link to comment Share on other sites More sharing options...
TSD Posted May 3 Share Posted May 3 Just remembered something from when I had a cracked head... When I parked overnight I released the pressure from the cooling system. That reduced or stopped coolant being pushed where it shouldn't go, and the engine started sweetly in the morning. That was my final diagnostic before pulling the head, since head gaskets for the TGV are a bit more spendy than for a 300TDi. 1 Quote Link to comment Share on other sites More sharing options...
jason110 Posted May 3 Share Posted May 3 I’d start with a a compression test. At least then you know the rings and valves are tight. Is there any actuator on the turbine? Could that be sticking? Quote Link to comment Share on other sites More sharing options...
miketomcat Posted May 3 Author Share Posted May 3 4 minutes ago, jason110 said: I’d start with a a compression test. At least then you know the rings and valves are tight. Is there any actuator on the turbine? Could that be sticking? Whilst I don't disagree with a compression test I can't help thinking that would be noticeable all the time. Turbo works as it should though it does sound whirry. Mike Quote Link to comment Share on other sites More sharing options...
hurbie Posted May 3 Share Posted May 3 7 hours ago, miketomcat said: However start up isn't great. It turns over fine and fires quickly but it runs rough (on 2-3 cylinders) and smokes it looks grey in the mirror. It will stay like this until you drive off then it clears and runs fine. to me this sound's like a fuel issue, have a good look at the fuel return spill rail . when the engine is running it gets way more fuel then it needs and sort off self purge the air out , hence why it's running better when driven a bit. (and maybee a doggy lift pump (spacer fitted when not needed ?? )) Quote Link to comment Share on other sites More sharing options...
jason110 Posted May 3 Share Posted May 3 I think it’s a fuel issue too. However, 10+ years working with heavy industrial diesel engines has taught me start with the basics and be methodical. one example, we had a exhaust valve seat let go. It was only noticeable on start up, no indication when running. Compression test showed it up with a water spout out the peak pressure sensor hole 😂 good luck, let us know how you get on 1 Quote Link to comment Share on other sites More sharing options...
steve b Posted May 3 Share Posted May 3 Fuel Is the lift pump yours or did it come with the engine? If it's yours is the mounting plate the same as the old engine? An electric lift pump would confirm/rule out supply issues before pulling the head etc. ? Steve Quote Link to comment Share on other sites More sharing options...
miketomcat Posted May 3 Author Share Posted May 3 I put the engine complete with only essential changes. The lift pump is an easy swap though. Mike Quote Link to comment Share on other sites More sharing options...
miketomcat Posted May 5 Author Share Posted May 5 Lift pump is pumping well and not draining back, neither is the injection pump. At some point I'll badger TSD and do a compression test. Mike Quote Link to comment Share on other sites More sharing options...
Ed Poore Posted May 5 Share Posted May 5 Admittedly on a 300 but I had the leak off rail with a tiny hole. It wasn't enough to leak any diesel during running conditions but if sat for more than about day then air would be pulled in very slowly and drain back down to the tank. It would take a few cranks to get started and then splutter a little bit until diesel got pulled through. Quote Link to comment Share on other sites More sharing options...
miketomcat Posted May 5 Author Share Posted May 5 This fires fine but runs lumpy till you drive off. Reving it doesn't seem to clear it either, it's most strange. Baring compression test and probably head off the only other thing I can think of is checking the valve clearances. Mike Quote Link to comment Share on other sites More sharing options...
Ed Poore Posted May 5 Share Posted May 5 What about checking rocker arm clearances first? That's a few minutes to check. Quote Link to comment Share on other sites More sharing options...
steve b Posted May 5 Share Posted May 5 I think my next step would be to crack the injector pipe at the injector one at a time while it's doing the lumpy tick over to see which one(s) are not firing properly then swap those injector(s) for the ones that are firing to confirm whether it's a cylinder or an injector. As above check valve clearances Maybe put all the injectors from the previous engine into this one? Steve 1 Quote Link to comment Share on other sites More sharing options...
miketomcat Posted May 5 Author Share Posted May 5 5 minutes ago, steve b said: I think my next step would be to crack the injector pipe at the injector one at a time while it's doing the lumpy tick over to see which one(s) are not firing properly then swap those injector(s) for the ones that are firing to confirm whether it's a cylinder or an injector. As above check valve clearances Maybe put all the injectors from the previous engine into this one? Steve Already changed the injectors, perhaps a little less smoke but not much. I'm fairly happy it's not fuel related. I'm leaning towards a small head gasket blow that semi seals as everything warms up, that would explain why reving it doesn't help but putting it in gear and driving off does. As loading the engine puts a lot more heat in quickly, either sealing up or giving a hotter burn allowing it to live with slightly down compression. Mike Quote Link to comment Share on other sites More sharing options...
steve b Posted May 5 Share Posted May 5 Ah, you have covered it all , now I see why you think it's a small HG compression leak , it would be interesting to do the compression test before tearing it off just for info and a before and after comparison of the facts. Steve 2 Quote Link to comment Share on other sites More sharing options...
miketomcat Posted May 12 Author Share Posted May 12 Well I haven't had chance to look much further into the starting issue, however yesterday I started it in the afternoon having been sat there since Friday night. It started perfectly on all four with just the normal puff of smoke. So the issue is definitely temperature related, whatever is causing it "seals" up as soon as it goes above around 20°c. This at least explains why it clears as soon as I drive off. Mike 2 Quote Link to comment Share on other sites More sharing options...
Wytze Posted May 12 Share Posted May 12 If it's that small of a gap, resetting the headbolts might do it Quote Link to comment Share on other sites More sharing options...
miketomcat Posted May 12 Author Share Posted May 12 1 hour ago, Wytze said: If it's that small of a gap, resetting the headbolts might do it To be honest if I'm going that far I'll change the head gasket at least I get to look inside that way. Mike Quote Link to comment Share on other sites More sharing options...
Wytze Posted May 12 Share Posted May 12 13 minutes ago, miketomcat said: To be honest if I'm going that far I'll change the head gasket at least I get to look inside that way. Mike Yes, peace of mind is a good thing to have. It helped me a good few years back. There started a cooling drip on the whole side of the head. No time to deal with pulling the head. Took the cover off, could see all the bolts, and thought.. meh.. why not. It stopped dripping and never seen a drop again. 1 1 Quote Link to comment Share on other sites More sharing options...
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