Mystery 300tdi oil problem

[piper109]

Today I was making a couple of injector pump adjustments, driving about 4-5 miles, about 3 times. Disco was running well. I hit close to 60 mph on my way home and pulled up the hills normally etc. especially my very steep road and driveway which I need second gear with 1800-2000 rpm to get enough turbo power to climb nicely. Vehicle is a '98 Discovery 1 which I converted from V8 about 5 years ago with an '96 300tdi engine and R380 gearbox with about 146K miles which I bought in Wales and carried home. Vehicle has run very nicely for 5 years, about 25 k, not my daily driver. I live in the North Carolina mountains. All seemed well so I cranked it up to reverse into my carport when I noticed the oil light stayed on.

After starting it a few times without even a flicker from the switch I decided to remove the switch. I cranked it over a couple of times with the switch removed and no oil came out of the port. Puzzled I removed the oil filter which was full and cranked the engine over a few times with the fuel solenoid disconnected. No oil came out of the filter housing.

I am really concerned as its as if the oil pump is not turning at all, certainly no oil is circulating. Level is good, within about 2mm of the full mark and oil is Rotella T6 synthetic 15w-40.

What have I broken ?? Car drove home normally and turbo was working well. A few minutes later I start the car and no oil pressure....none at all. Where do I start looking?? Any ideas? I have never disassembled the TDi as it had recently had a new cylinder head, engine repaired in Shrewsbury before I bought it. I removed the oil pan/sump before installing it into the Discovery and all was clean. Power has been good and I can reach 80, even with the aircon in use. Thanks Steve

[Boydie]

Okay, I assume that you have a reasonably new oil filter installed so loosen it about 5-6 turns and with the engine at idle you should have an oil flow, if not turn off the engine and get a copy of Rave as your oil pump is kaput.

If you have an oil flow the oil pump is working, next re-tighten the filter and check that the oil thermostat is operating. (immersion in a pan of hot water will confirm this) and next that you have oil flow through the oil cooler.

If your investigations indicate that there is no flow from the oil pump the next thing to look at would be that the oil pick-up mesh in the sump isn't blocked with accumulated crud, to check this remove the sump and check it.

If it is the oil pump that is no longer pumping I think that this can be done with the engine in and with the radiator, intercooler, grille etc. removed but it wont be an easy job as you will need to remove not only the front timing belt cover but also the timing cover rear plate. This will also mean removal of the Fuel Injection Pump, water pump, power steering pump and alternator, harmonic balancer etc..

If you have to do this replace the timing belt and fit all new oil seals as a matter of course.

Ensure that the motor is at TDC with a retaining pin in the flywheel to make re-setting the timing easier, before you remove the FIP put the retaining pin in it to lock it in position.

[piper109]

My oil filter is reasonably recent as I changed the oil about 2-3000 miles ago. I removed the oil filter completely and turned the engine with the starter, fuel solenoid disconnected. I perceived no oil flow and I assume the pump is not turning. From my research yesterday, I assume the oil pump engagement with the crankshaft is kaputt and I guess I will have to remove the timing cover and all that you have mentioned. Removing the crankshaft pulley will be the most difficult as I dont have the tool to stop the shaft from turning. I replaced the timing belt before fitting the engine 5 years ago and I tightened the crankshaft on the ground with the flywheel locked with a steel flat bar from the flywheel to bell housing. I assume at this point that the pump rotor to crankshaft engagement means is damaged, perhaps the crankshaft dogs are shot. It looks like I am in for a big job and parts for 300TDi are not easy to get in this country. I suppose I am fortunate that the oil pressure light stayed on while I was on my driveway and as far as i know all was working OK up to that point. I did not notice any oil pressure light while driving home and had no problem driving up my very steep access road. Engine started instantly and ran normally and no knocking etc before I removed the pressure switch and filter and i am staggered to find I have no oil flow at all.

[Sheffield]

As mentioned by Boydie before you start dismantling the engine I think you should look in the sump in case the oil pick up pipe has come off. Not unheard of I believe.

[Boydie]

Lets assume that you have checked the oil pump pick-up and that its clean and still connected (they do have a history of becoming disconnected).

Removal of the crankshaft bolt is not a nightmare if you have the right tool. The required tool is a "sledge bar driver" (at least that's what they are called here in Australia).

This tool is a 3' long bar with a right angled 1/2" drive on one end and a belled striking area at the other. The correct size socket is fitted on the 1/2" drive and the belled end of the 3' long bar is struck VERY hard with a lump hammer - in this case to unscrew the bolt - it works similar to an impact driver. On re-screwing it use a dab of Loctite and a torque wrench - do not adapt the method you used initially, you can damage the crank, to say nothing of making life hard to remove it a second time.

Timing belts should be changed every 60000 miles or 100,000 kilometres, don't go by periods of time.

Remove the sump and check the oil pump pick-up and that there is no blockage to the oil pump- you may be pleasantly surprised.

[piper109]

Yes, for sure I will drop the sump and check the oil pump pick-up and perhaps the pressure relief valve too. We had heavy rain yesterday and I never did get the Disco backed into the car port so it might be fun. I have seen the sledge bar driver tool mentioned on a Youtube segment (used to be Trailerfitter I think) and I would have to make one. I might just use the "starter method" although I dont like the idea. I think my socket for the crank bolt is 3/4" but as I retired and have moved to a rural area since I did the engine swap, I have to dig out all my "serious" tools.

Thanks for the encouragement :-) Steve

[piper109]

Well I dropped the sump this afternoon. It was not fun but fortunately the rain held off. My carport roof would not allow me to jack the Discovery up so I left it outside and worked on the gravel.

Getting the pick-up assembly unscrewed was a devil, mostly the two M5 fine thread screws holding the rear side of the pick-up assembly to the main bearing 4 cap bolts. I think they had been over tightened or something similar. I saw no evidence of clogging or fracture and everything was screwed in place. The O-ring where the pick-up tube enters the front housing was intact and showed no signs of leaking there though I confess I have not yet done a thorough inspection. I think there has to be an easier way to do the job as I could not remove the sump completely until after I had removed the pick up assembly and return pipe and lowered them.

I have not yet removed the pressure relief valve as I was worn out fighting the pickup and sump. Every thing looks shipshape except I did find a broken valve stem cap in the bottom of the pan so i have something else to check into. Looks like my next job will be removal of the timing belt cover and checking the oil pump rotory parts and crankshaft. Steve

[Boydie]

Before you do that Steve, run a suction line from the oil pump to a oil filled container -- (the original sump will be fine) --- and turn the motor over to see if you have suction.

At this stage remove all four glow plugs as turning the motor will be a lot easier with zero compression and it will spin quicker. If you don't have any suction, and if there is nothing such as crud or swarf holding the oil pressure valve open then removal of the oil pump is the next step.

[piper109]

Boydie, I believe I follow your logic in your suggestion. You are saying that a bad or clogged pick-up pipe or a stuck pressure relief valve can prevent the oil pump from sucking oil and circulating it, even if it is turning with the crankshaft. I have removed the pick-up pipe and seen that all seems in good condition, not loose or clogged.

Today I removed the pressure relief valve. It slid in and out smoothly and taking it out and cleaning it gave me no sense of that It could have been jammed open. Everything is clean, shiny and looks in good shape. Spring is not broken. No sign of swarf or trash/debris.

If I did the test you are suggesting, would it not be exactly the same as when I had everything assembled and running? What else could be causing a complete lack of oil flow, other than a pump that is not turning? Thanks, Steve

[Boydie]

Steve, if you are totally satisfied than nothing is preventing oil from being drawn into the oil pump then it has to be the pump. The crankshaft has two flats machined onto it and this is the drive mechanism for the pump, the corresponding flats machined in the pump rotor could conceivably be worn to the point that the pump rotor is simply not rotating, take some photos if this is the case as I've never heard of this before.

Are you okay for obtaining new parts? DO NOT use Bri***ts !!! Go for Land Rover original, The oil pump is the heart of the lubrication system, nothing less than perfect will do. Incidentally I personally would fit a new pressure relief valve and spring as well.

Lets know how you go.

[piper109]

Thanks Boydie, That's a good idea to replace the pressure relief valve and spring. My valve plunger has some "lapped" areas. Yes I know better than to use Bri***ts. Getting parts for these engines is not easy In North America but I do know a fellow Brit or Pom who runs a company called Rovah Farm and I can trust what he gets. Right now i am fighting the crankshaft bolt and using the starter method. I have destroyed my 1/2" breaker bar and my replacement has not loosened it....just stalls the starter. I have found someone on ebay who sells a tool that bolts to the 4x M8 threaded pattern in the pulley which has an arm that can react against the frame while I use a cheater tube with my new breaker bar. Hopefully that will get it done.

I noticed in your posting that you said to remove the alternator, water pump, PS pump etc. Is that really necessary as it looks like the timing chest back cover can be removed with that stuff still in situ? I will keep you posted as I make progress. I read another article on a LR forum where someone had a similar problem and the pump parts were worn as was the timing cover pocket which with hot thin oil dropped the pressure down really low.

I plan on replacing the timing belt too. Cheers, Steve

[Boydie]

Steve, I would remove them just to improve access. Again, seeing as the access is there I would also replace the water pump and infamous "P" gasket while you're at it and have a good look at the welch plug adjacent to the "P" gasket, --- but don't use the pressed metal "P" gasket, use a composite one.

Seeing as how you have the sump off remove the centre main bearing cap and check for any bearing damage due to lack of lubrication, easy enough to replace it and to torque it up again after, while you have it off for inspection I would check the bearing clearances with a strip of bearing thread gauge as well -- if they are worn, replace them along with the big end bearings, you dont want to be doing this pooop again any time soon.

[piper109]

Well I have dismantled everything at present. The inner timing case with the oil pump is in my hands. Fortunately after removing the crankshaft bolt, which was a real bear, everything else was pretty straightforward. Even the timing belt and idlers look good

The crankshaft flats look good and basically unworn. The pump rotors do not look bad either. Close to 20 years old, 170k miles, just a few wear ring traces on the faces. I did notice about 8 thou" play between the outer rotor OD and the aluminium timing case. That seems a bit loose to me but I need to convert my figures to metric to compare. (showing my age LOL). The inner rotor has about 1 mm or forty thou play on the flats. Inner to outer rotor engagement seems pretty tight. The cover plate shows some wear rings but nothing deep. A thou or two at most. I did notice that the screws holding the plate on were a tad loose. Unscrewing them was effortless. I would have expected to have to break them loose a little. I'm not sure if the timing case where the pump runs is within limits or not

It could have been that the pressure relief valve was the problem after all. I saw no evidence of trash or debris however but the spring is 46mm long instead of 60 something. The plunger shows some wear shiny lapping marks. Oil might have been a little hotter than usual as I had been making IP adjustments and driving up hills before the issue.

I have to shop for new parts now. For sure the pump rotors and relief valve parts will get replaced. I may look for a timing case inner too.

I still have to check main crankshaft bearings and big ends for wear. Steve

[Boydie]

Keep us up to date, my guess is the pump is caput, its simply too worn to generate pressure. Don't forget to check at least one of the main bearings for any wear.

[piper109]

I finally received the new parts. Vehicle is back together and working well. Quite a lot of work. I replaced the oil pump rotors with new from UK. I also replaced the oil pressure spring but not the plunger as the quality was not good and I miked it up at 2 thou out of round (.002") ! I would have needed to force it into the valve drilling in which case it would not have worked and would have been impossible to remove so I just used the original. Replacement will be sent back to supplier.

I replaced the timing belt and set the timing accurately and rechecked my work and settings per the www.Landroverweb.com/ 300tdi overhaul pdf. Starting was pretty much instant. Oil light went out after about 2 seconds and stayed out. I am going to fit a manual pressure gauge but it is not yet done.

Subsequent starting turned light off after about 1 second. All the bottom end bearings are standard and were not replaced. I saw no need as they were all good. I am using the same Shell Rosetta T6 synthetic oil (5w40) but I may replace it with 15w40.

I'm still not sure what the problem was but happy with the way its running now.

Steve

[Boydie]

That's great news Steve, just a small thing but I wouldn't be wasting your money on using full synthetic oil, it's a diesel engine and a mineral engine oil is preferred 10w-40w and changed every 10,000 kilometres or 6000 miles depending on what odometer you have. Change the fuel and oil filters at the same time.

My engine has now done 225,000 kilometres since I re-built it (140,000 miles) and it still has 50psi oil pressure when cold and 35psi when up to temperature (90 degrees C) and 15psi at idle 750rpm. A good gauge is, I believe essential, - an electric sensor VDO is what I have and it is very accurate.

Lets know how you progress, and well done on the timing belt renewal.

[piper109]

Thanks for the comments Boydie. I know I don't need the full synthetic (Shell Rotella T6, not Rosetta, I was tired !) but the fact is its what I use in my wife's VW tdi Beetle and its easy just to use the same, especially as its purpose made for diesel engines. At $18 a gallon here its not very pricey. I even use it in my riding lawn mower.

The pressure gauge is in hand and will be installed very soon. Cheers, Steve

[piper109]

Well I have installed my pressure gauge (not in the dash yet) and taken note of the oil pressures. About 45 psi at idle when close to being cold. 16-17 psi at idle when hot. At 2000 rpm when hot its a bit above 35 psi. Engine has about 170,000 miles and never been rebuilt that I am aware of although the cylinder head was replaced because of an over heat several years ago, before I bought it. Engine seems to be a smidgen noisier than before (piston slap I think) so its possible that the timing is a little more advanced than it used to be. Steve

[Boydie]

The "piston slap" may be pre-ignition if you have advanced the timing too much, this can lead to piston crown damage. Oil pressures are spot on and would indicate that your engine bearings are in good condition.