300tdi running rough over 2300rpm?

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andyhayleygt4

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24
Hi all. New to this but have a problem already. Got a 300tdi discovery. Starts and runs ok until around 2300rpm. After this it starts running rough and smoking quite alot. Been told it could be head gasket. No usual signs of this. Temp stays fine, no oil in water, no gunk under oil filler cap or raised oil level. Changed fuel filter and air filter but still same. Runs and drives fine until over thay rev range and gets worse with higher revs. Cheers.
 
I have the same problem was going to do the sedimentor today but run out of time i will attempt tomorrow and keep you posted
 
Iv changed fuel filter and i have found the water trap at the back but i couldnt get it off, couldnt turn the drain plug either. Does it spin off like a filter? Not checked intercooler pipes but have tried running it with main turbo feed pipe off. Still same.
 
Iv changed fuel filter and i have found the water trap at the back but i couldnt get it off, couldnt turn the drain plug either. Does it spin off like a filter? Not checked intercooler pipes but have tried running it with main turbo feed pipe off. Still same.

It has a bolt through from the top, 11mm spanner I think.
 
oh ye just like a JCB style fuel filter. Ill do that first job tomorrow and keep you posted. Cheers everyone.

Sounds like its getting starved of fuel on high revs and turbo boost, however the smoke dunt fit in and sounds like its either overfueling if its black and not burning it if its white.

Timing belt ok, injectors, made sure air filter is ok, tappets etc etc. Is it one cylinder thats dropping out on revs, try cracking off each injector at a time to see if it shows it up.
 
not sure about timing, air filter is ok and not checked tappets. iv tried cracking the injectors on tick over and the engine note changes on each one. Shall i try cracking them off at higher revs? (will this make a difference?)
 
My suggestion, as very similar happened on a friends gaylander, the turbo pipe had split and when revs increased and hence the air intake requirement the turbo pipe, being split, closed and restricted the air flow, kicked out a hell of a lot of black smoke

I would check the turbo air pipe closely first
 
My suggestion, as very similar happened on a friends gaylander, the turbo pipe had split and when revs increased and hence the air intake requirement the turbo pipe, being split, closed and restricted the air flow, kicked out a hell of a lot of black smoke

I would check the turbo air pipe closely first

Yep I would agree, over fueling because of lack of air, and it would help if we knew what colour of smoke and if it smelt of oil, could take the outlet pipe off and see if it still misses without boost, and see if the turbo is ****ing out oil.
 
I took the pipe off the turbo and there is a bit of oil in the pipe but not much. Not looked at the intercooloer side yet. Could the exhaust manifold blowing quite bad have anything to do with it? The smoke is like a white colour but does have a bit of an oil smell to it. I know this might sound silly but what do you mean by the outlet pipe?
 
dose it do it undr drive or can you repeat this when parked and you pick the revs up on the engine?

have you removed the pipes and inspected as my freind had a turbo pipe come appart inside and would only do it under boost, we came to this conclusion by removeing the pipe from the engine inlet and reved with out turbo useage if tevs go up over your stated then check for blockages in the air system.
 
I took the pipe off the turbo and there is a bit of oil in the pipe but not much. Not looked at the intercooloer side yet. Could the exhaust manifold blowing quite bad have anything to do with it? The smoke is like a white colour but does have a bit of an oil smell to it. I know this might sound silly but what do you mean by the outlet pipe?


Hi Andy (hope I got that right?) your symptoms are not at all unusual and are often down to one of the following:

1. Fuel sedimenter full of crâp - to investigate this you will need an 11mm ring spanner and a 2ltr ice cream tub or similar to catch any spilt fuel.

Get under the car and locate the fuel sedimenter, feel the top of the unit and find the 11mm bolt and undo it. The sedimenter bowl is often stuck onto it's rubber seal so it needs a tap with a rubber mallet or similar to detach it. Have your catch tank ready as there will be fuel !!! Once you have removed the bowl there will be no further fuel running out, so don't worry you won't empty the contents of your tank all over your drive :D

Almost certainly there will be a sort of mayonnaise/raw egg looking stuff in the bowl - clean thoroughly and reinstall.

Run the engine on a high tickover, about 1500rpm should do it, so that the system purges all the air out.

Now try a run in the vehicle - problem cured or not?

If no, continue down the list:

2. Locate the turbo and the rubber elbow pipe coming off the bottom of it. Undo the clips and remove the rubber elbow. Examine it carefully for any splits or breaking up (delamination) on the inside. If all looks good, reinstall. If you have ANY doubts about it's condition, replace it.

3. Now check the other rubber hoses that go between the other end of the metal pipe and the bottom on the intercooler and the pipe that goes between the top of the intercooler and the inlet manifold. This may be made entirely of rubber or, if the vehicle still has it's EGR valve (disc looking thing on the exhaust manifold) the top pipe will be part rubber and part metal.

4. If the exhaust manifold is blowing between the block and the manifold this needs resolving. It may be that a retaining nut has come loose in which case tighten it up and check for leaks. Alternatively, you will need to replace the exhaust manifold gasket. To do this you need to remove both the inlet and exhaust manifolds as the gasket is in one piece for both elements.

Once done, road test and see if problem remains - yes or no? If yes go to next step:

5. The last thing I can think of is the fuel lift pump. These are cheap to buy and easy to replace, taking perhaps 30 mins and £20. I suggest this as poor performance is sometimes caused by poor fuel delivery and by this stage you will have done pretty much everything else in the fuel delivery chain.

Best of luck and let us know how you get on

Cheers
Dave
 
Cleaned my sedimentor today. Yes loads of rubbish and small amount of water real easy job. Has it cured my lack of power problems? Not sure yet only done 5 miles since fix but seems ok. i will add another post tomorrow i need to do 50 miles so should give some sort of conclusion
 
Cleaned my sedimentor today. Yes loads of rubbish and small amount of water real easy job. Has it cured my lack of power problems? Not sure yet only done 5 miles since fix but seems ok. i will add another post tomorrow i need to do 50 miles so should give some sort of conclusion


That sounds encouraging, let us know how you get on would you Louis?
 
Changed my sediment bowl today. Was a bit of gunk and water in it but didnt really make a difference. Next i took pipe off from top of intercooler to inlet manifold. There was loads of black gunk. I cleaned it out best i could and tried it with pipe still off. At first it was like it was back firing when revved. It was actually sparking a small amount in the inlet, then all of a sudden it just cleared. It now revs up fine with no smoke and not miss firing. I then took the exhaust and inlet manifolds off to solve the exhaust manifold blowing and found only the 2 front bolts holding it on. All the others are missing. Not broken in head, just missing. I have now left all metal pipes and inlet to soak in some de-greaser and have ordered a gasket.
Not sure exactly where the problem is but would think it mut be the pipes or the intercooler itself. Can the intercooler be tested and cleaned at all? Next job to get it all back together tomorrow and try it again. Any help with where the problem might be now and i would be very gereatful. Cheers to everyone for all the help with this problem. Ill keep you posted on what happens next.
 
Not sure exactly where the problem is but would think it mut be the pipes or the intercooler itself. Can the intercooler be tested and cleaned at all? Next job to get it all back together tomorrow and try it again. Any help with where the problem might be now and i would be very gereatful. Cheers to everyone for all the help with this problem. Ill keep you posted on what happens next.


Take the intercooler out, fill with White Spirits or petrol and using rags bung up both holes, then agitate for two mins and leave overnight.

In the morning, empty out the cleaning fluid, half fill with fresh fluid agitate and empty, then allow to thoroughly dry.
 
Sound. Will do that tomorrow and see how it goes. Dont suppose anyone knows how to get the front wiper motors out. If it is an easy job or not. Cheers
 
I cleaned my intercooler out with paraffin with a squirt of fairy liquid mixed in, bunged it & gave it a good old shake. Fairy lets you rinse it out with a hosepipe, get it as dry as you can.
 
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