Judd Posted June 27, 2011 Share Posted June 27, 2011 I have just purchased my 1st series 3 it is a 2.25 diesel 1977 (only had it a week) and have noticed that my oil pressure light has been co,ing on and I have been using a lot of oil the engine is fine when cold but about 15mins after the engine is at running temp the oil pressure light starts to flicker at low revs and will after a further 10 mins remain on, I have been told to remove my oil bath air filter and see if it is that causing part of the problem, I have checked for leaks and can't see any but am getting a lot of black smoke out of exhaust I'm thinking maybe piston rings or valves I would appreciate any ideas as what to check as I have never had this problem is it going to be a new engine or is it something simple ??? Many thanks. Judd Quote Link to comment Share on other sites More sharing options...
mickeyw Posted June 27, 2011 Share Posted June 27, 2011 Hi Judd and welcome to LR4x4 It sounds like your engine is due for some TLC. If it's using a lot of oil I would suspect the rings, especially if it's producing blueish smoke from the exhaust. Black smoke is usually unburned fuel! Does the exhaust smell very oily? You also mention the oil light coming on. This could be actual low oil pressure, caused in part by low oil level. It could also be worn main bearings. Another thought - was the vehicle used much prior to your purchasing it? If it's stood unused for a long time the piston rings may simply be sticking and letting oil past. Some Redex and a good run might sort this out. Quote Link to comment Share on other sites More sharing options...
Judd Posted June 27, 2011 Author Share Posted June 27, 2011 Since owning the truck I have used 10ltrs of oil covering about 750 miles the exhaust is only kicking out black smoke and doesn't smell oily or unusual, when the oil pressure light comes on I top the oil up, I bought the truck from a garage who gets land rovers to a road worthy condition, it had also been put through an mot after having suspension replaced but the previous tax disc was 3 years out of date so am guessing it has been stood out of way I have now ordered new fuel filter oil filter and will pick up a bottle of injector cleaner, Many thanks for reply will keep you in formed. Quote Link to comment Share on other sites More sharing options...
Christophers1247 Posted June 29, 2011 Share Posted June 29, 2011 Using 10 ltrs of oil for only 750 miles is not good. It sounds like it is either piston rings or valve stem oil seals. In an ideal world you would see blue smoke for oil and black for over fueling but this is not always the case. you could find out if it was the rings by doing a compression test or get it done by a diesel/land rover garage. Low compression would suggest piston rings. should be around 425 psi (if my memory serves me right). Quote Link to comment Share on other sites More sharing options...
Snagger Posted June 30, 2011 Share Posted June 30, 2011 Black smoke is a sign of poor fuel spray (blocked/dirty) injectors, excessive fuelling or excessively advanced fuel timing. 10l of oil in 750 miles is bad news, though. I doubt it's the valve stemn seals - they will lose a bit of oil, but not that much and their biggest symptom would be blue smoke for the first couple of minutes on engine start as the oil pooled on the piston head burns off. I'd suspect the rings and bores, perhaps even cracked pistons or a bad head gasket, but you don't report any starting problems that would be expected with any of these. Do you have any signs of external leaks? It could be that the black smoke of the fuel issue is masking the blue oil smoke, but a big leak when the oil system is under pressure could also be the cause of the oil loss. It's not unknown for the dipstick to indicate incorrectly, usually because the bell shaped cap has moved on the stick or the guide tube has been incorrectly set in the block - over-filling with oil would cause the rings to gum up as the oil gets splashed up the bores by the crank shaft whipping the surface of the sump oil - that oil would get burnt off, the sump level dropping and the dipstick indicating a needed refill. However, if the oil pressure light comes on, that suggests the oil level really is getting low. When I first bought my 109, the owner claimed the engine had been overhauled, but I found it was using about a pint of oil every 100 miles (about half your losses) and was utterly gutless. The engine was utterly worn out (along with the rest of the vehicle). Since you bought the vehicle from a commercial vendor, the seller had the legal obligation to make sure the vehicle was "fit for purpose". I think it's highly debatable that your vehicle is fit for the road if it's losing that much oil and producing that much smoke. I'd take it back and demand it be rectified or the vehicle be returned and a full refund given. Quote Link to comment Share on other sites More sharing options...
Judd Posted June 30, 2011 Author Share Posted June 30, 2011 I have spoke to the guy I bought the truck off and have found out that it was not a business sale it was a private and it was only picked up from his business address But the good news is I have been given another 2.25 diesel engine and am currently giving the engine a thou her check and replacing a few gaskets while I have access to everything good thing is parts a cheap Owing a landrover is just part of the experience Quote Link to comment Share on other sites More sharing options...
Christophers1247 Posted June 30, 2011 Share Posted June 30, 2011 I have just pulled the cylinder head off a 200tdi engine from a defender this morning with the exact same issues you are having massive oil consumption no signs of leaks. cylinder's 2 and 3 are badly worn as are the rings and piston 3 has a big crack on the crown. this was due to the under piston oil jets failing faulty oil pump and the previous owner messing with the injection pump timing causing the engine to run lean. Quote Link to comment Share on other sites More sharing options...
Snagger Posted July 1, 2011 Share Posted July 1, 2011 I have spoke to the guy I bought the truck off and have found out that it was not a business sale it was a private and it was only picked up from his business address But the good news is I have been given another 2.25 diesel engine and am currently giving the engine a thou her check and replacing a few gaskets while I have access to everything good thing is parts a cheap Owing a landrover is just part of the experience If he did not specify that before the sale, then as the sale was conducted at his business premises, it was a business sale. He sounds like a rogue and you should go to trading standards. Time to name and shame... Quote Link to comment Share on other sites More sharing options...
TheRecklessEngineer Posted July 1, 2011 Share Posted July 1, 2011 previous owner messing with the injection pump timing causing the engine to run lean. Errmm...Diesels always run lean. Even when producing clouds of black smoke they are still running lean. You'll melt stuff pretty quick if they ever run rich! Quote Link to comment Share on other sites More sharing options...
Snagger Posted July 2, 2011 Share Posted July 2, 2011 Errmm...Diesels always run lean. Even when producing clouds of black smoke they are still running lean. You'll melt stuff pretty quick if they ever run rich! Yep - petrol engines with carburettors have a specific mixture and the amount of air entering the engine is controlled, not just the fuel. Diesels don't have any air control; it's the amount of fuel delivery only that controls engine output. Black smoke from a diesel is a sign of incomplete fuel burn, either through having too much injected to burn with the available oxygen, but that only happens with full throttle operation (otherwise the engine will just accelerate to even out the fuel/oxy mix), poor spray pattern or advanced timing (fuel injected before the peak compression pressure and temperature are reached, allowing fuel to condense on the bore and only burn its surface). Quote Link to comment Share on other sites More sharing options...
Christophers1247 Posted July 3, 2011 Share Posted July 3, 2011 Standard 200tdi with bosh two spring 0432193879 injectors with nozzle type dsla145p208 and a garret t25 turbo at standard boost pressure 0.78 bar max has a stoichiometric air fuel ratio of 10:1. as you will all know Dodecane C12H26 has a=18.5 and molecular weight 170 so if you do the math AFR = a(MWO2+0.79/0.21*MWN2)/MWfuel most diesels come out with an optimal fuel to air ratio of 14.95:1 so standard tdis are not far off . now consider the 200tdi engine mentioned before. this had a fuel air ratio of 17:1 due to as said before fuel injection pump and turbo being messed with. this engine is running on the dangerous side of the optimal stoichiometric fuel air ratio for this engine. and due to the wear of surrounding components such as the oil and water pump cooling was not as efficient as a new unit this caused the engine to overheat and do the aforementioned damage. saying the engine was running lean is the wrong terminology but it was the best way to describe the above without going into to much detail. Quote Link to comment Share on other sites More sharing options...
TheRecklessEngineer Posted July 4, 2011 Share Posted July 4, 2011 I'm not getting into an argument here. Not sure what you're waffling on about above, it does seem that you're confusing compression ratio and AFR. Quote Link to comment Share on other sites More sharing options...
Snagger Posted July 4, 2011 Share Posted July 4, 2011 Standard 200tdi with bosh two spring 0432193879 injectors with nozzle type dsla145p208 and a garret t25 turbo at standard boost pressure 0.78 bar max has a stoichiometric air fuel ratio of 10:1. as you will all know Dodecane C12H26 has a=18.5 and molecular weight 170 so if you do the math AFR = a(MWO2+0.79/0.21*MWN2)/MWfuel most diesels come out with an optimal fuel to air ratio of 14.95:1 so standard tdis are not far off . now consider the 200tdi engine mentioned before. this had a fuel air ratio of 17:1 due to as said before fuel injection pump and turbo being messed with. this engine is running on the dangerous side of the optimal stoichiometric fuel air ratio for this engine. and due to the wear of surrounding components such as the oil and water pump cooling was not as efficient as a new unit this caused the engine to overheat and do the aforementioned damage. saying the engine was running lean is the wrong terminology but it was the best way to describe the above without going into to much detail. There is an optimum ratio in any chemical reaction to use all the atoms or molecules in the reaction, but diesel engines don't work like that - they only try to burn all the oxygen at full throttle. Like I said, you don't control the amount of air entering a diesel engine, just the amount of fuel. If you richen the mixture, the engine will accelerate. If you weaken the mixture, it'll slow down. Stick a turbo on it and the higher the egt, the more the induction pressure will increase, forcing more air in and the fuel pump will automatically compensate, but the egt rise follows the input of more fuel from the throttle movement, so again, the engine rpm control is down to the fuel metering and richness. Quote Link to comment Share on other sites More sharing options...
TheRecklessEngineer Posted July 4, 2011 Share Posted July 4, 2011 they only try to burn all the oxygen at full throttle. Spot on Snagger, but even at full throttle there's still about 20-30% excess air (depending on the engine). Swirl is largely the limiting factor in how much fuel can be injected. More modern DI engines have much better swirl patterns than earlier designs - one reason why modern diesels are more powerful for a given engine size without smoking. The engines I've been looking after (my babies!) run with about 20% excess air at full load. Swirl is created in the cylinder by using a cunningly shaped piston crown that creates a toroidal swirl pattern into which the injector fires fuel. I believe DI automotive engines use a similar type of swirl. Quote Link to comment Share on other sites More sharing options...
Judd Posted September 25, 2011 Author Share Posted September 25, 2011 sorry not been on in a while but i have cured the oil burning situation in my landy upon further investigation in to the problem i removed the head and checked the barrels for damage all are clean and perfect i checked the rings and they seem good aswell but when removing the head when checking the head i could see where oil had been leaking between 2 and 3 cylinder , new head gasket a good flush and service and the smoke has stopped, and oil not been burnt Now for the next job on the list Quote Link to comment Share on other sites More sharing options...
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