Tomas4x4 Posted October 5, 2010 Share Posted October 5, 2010 Hello all, I have a 1996 300tdi disco, 130k and it is seriously underpowered, I thought it has been lacking for a while now but last week it became considerably worse, it struggles up hills, and living in North Wales, its an issue, also it uses an uncomfortable amount of diesel. It doesn't smoke or use oil and I have changed the lift pump, the EGR has been blanked off and I have recentely cleaned out the sediment filter, neither is it using water so I dont suspect the head gasket. What I did notice was oil seeping out of the turbo hose connections between the turbo and intercooler and the inlet manifold. I removed all the pipework and the intercooler and there is no cracks or splits but there is a coating of oil in the pipes, the intercooler is a little grubby but ive seen worse so im suspicious of the turbo now. What im asking is if anyone has had similar trouble and would you agree that it is the turbo that is faulty? Are there seals inside that can be replaced or is it a case of a new unit? As ever all tips and pointers would be greatly appreciated! Cheers. Tom. Quote Link to comment Share on other sites More sharing options...
adam300Tdi90 Posted October 5, 2010 Share Posted October 5, 2010 Yes 'EXCESS' oil in the turbo pipes does hint at oil seals in the turbo being past it. However, unless this has caused low oil level for the bearings AND then caused damage to the turbo, this doesn't necessarily cause a loss of power. Have you tried to operate the wastegate actuator (Manually)? Does it seem like there is no boost at all? Make sure you don't have split turbo hoses. Make sure the wastegate actuator works (isn't 'stuck'). I've heard one can refurb a turbo oneself, but I wouldn't do it TBH. Recon/replacement second hand unit seems the best way to go. Hope this helps, Ad. Quote Link to comment Share on other sites More sharing options...
boyt Posted October 5, 2010 Share Posted October 5, 2010 turbos pass oil, pipes will be coated lightly, if its pass to much, eg seals failed it will smoke, normaly quite badly, check play up and down, make sure the blades cant/have touch the sides/housing, in the world of mercedes benz we get the turbo shaft snaped on the exhaust side, inlet looks ok no abnorble play in shaft but complete lack of power, u can either check exhaust turbine and make sure they spin together(not sure if u can excess the exhaust side on the 300?) or we start the vehicle with the inlet pipe off so u can see if the turbine is spining, another thing is waste gate could be seized open, causing lack of power, check that you can move the waste gate, Regards Andy Quote Link to comment Share on other sites More sharing options...
davek0974 Posted October 5, 2010 Share Posted October 5, 2010 Temporarily fit a boost gauge, its a great tool for an insight into turbo function. I used one to diagnose a failed turbo on my 300tdi, i might fit it permanently when i get a chance. Quote Link to comment Share on other sites More sharing options...
Tomas4x4 Posted October 5, 2010 Author Share Posted October 5, 2010 Fitting a boost guage sounds like a sensible idea, I believe I can get access to one of those so I can do that asap. How do I locate the waste gate actuator? If it is siezed, is it easy to free it? I shall give the turbo a good check over for play. Any tips on how's best to clean out the intercooler? Thought it might be worth doing that. Many thanks. Tom. Quote Link to comment Share on other sites More sharing options...
Tomas4x4 Posted October 6, 2010 Author Share Posted October 6, 2010 I tried to move the waste gate actuator by attaching a pair of mole grips to the end and pushing/pulling as hard as I could and it did not move so im guessing thats seized? I also removed the inlet pipe from the turbo and felt for play in the fins and theres about 2mm of play there, is that too much? I started the engine and could hear the fins spinning and could hear them spinning faster when I increased the revs, but they were a bit noisy, is that normal? And finally I spotted an oil leak from below the manifolds and on top the engine next to the inlet manifold, the rocker cover gasket had been replaced recently, could this be related? Sorry for all the questions, any help is greatly appreciated! Cheers. Tom. Quote Link to comment Share on other sites More sharing options...
davek0974 Posted October 6, 2010 Share Posted October 6, 2010 Careful with the actuator, its a bit delicate. The best way to get access is to pull the manifold/turbo off, the actautor rod can then be slipped off and the wastegate can be tested. I checked and set my replacement turbo actuator by connecting it up to a regulated compressed air supply at work, tuning it to 12psi and then adjusting the rod length so it 'just' slips over the actuator pin, lock it up and fit a new clip - job done. When tested with the boost gauge it regulated boost to just under 12 psi which i was happy with and proves the method worked. The shaft can be sloppy sideways but not much endways and the rotor should never touch the housing. Try not to spin it too much as they run in oil bearings and there's no oil when the engine is off. Rocker cover can leak, maybe worth investigating further, wipe down and re-check later. Dave Quote Link to comment Share on other sites More sharing options...
Range Rover Blues Posted October 8, 2010 Share Posted October 8, 2010 Clean the intercooler with parafin or deisel over night then a good degreaser anf inally dry it out. If the boost guage shows you are getting good pressure at the turbo outlet then you could be loosing pressure in the intercoler. Quote Link to comment Share on other sites More sharing options...
sheltie50 Posted October 9, 2010 Share Posted October 9, 2010 At the risk of being shot down, anyone changed the air filter Quote Link to comment Share on other sites More sharing options...
mahon257 Posted October 14, 2010 Share Posted October 14, 2010 Turbo gauge should be fitted to the Plenum chamber. LR provide a pre-threaded hole for this purpose (which has a bolt in it!). I've just done this - will post pics and part nos. later today. Quote Link to comment Share on other sites More sharing options...
mahon257 Posted October 14, 2010 Share Posted October 14, 2010 Turbo gauge should be fitted to the Plenum chamber. LR provide a pre-threaded hole for this purpose (which has a bolt in it!). I've just done this - will post pics and part nos. later today. Turbo Gauge hilarities: Quote Link to comment Share on other sites More sharing options...
Tomas4x4 Posted November 13, 2010 Author Share Posted November 13, 2010 Thanks for all your comments guys, sorry its taken me so long to get back. I finally managed to find some time to sort the truck out properly, I started by pulling the manifolds off and changed the gasket which was shot, I then flushed out the intercooler and the inlet manifold (a dirty, dirty job). Whilst the turbo was off I gave it a good check over, the boost pressure guage read just under 1 bar when running which seemed ok to me, the lever on the actuator was a little sticky but some wd-40 sorted that out! I also replaced the turbo hoses for new ones and completely removed the egr. I was experiencing poor staring after I took the fuel sedimenter apart so assumed air in the fuel, sorted that out, and after all that what a difference! its like a new truck now, plenty of power and almost a pleasure to drive, wish id done it sooner. Now to sort out the never ending list of things to do to the truck... Many thanks for your help and advice! Tom. Quote Link to comment Share on other sites More sharing options...
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