300tdi Vibrations / low power around 3000-3400rpm

[mattims]

Hi,

I have a 1998 300TDI 110, its done 380,000kms but the previous owner swapped the engine with a rebuilt one about 60,000kms ago.

Ever since I have had it has had a vibration and loss of power as you get just above 3000rpm, it feels like a drivetrain vibration (I can feel it through the seat and the floor), but its at the same RPM independant of gears, and it seems to loose power at this point to so I am guessing it is engine related.

In neutral the engine will rev past 3000rpm without any vibrations like this that I can detect, and it seems to be worse the more load on the engine, ie if I let it rev past 3000rpm at half throttle in 1st or 2nd gear its not nearly as bad as 3rd or 4th gear and full throttle.

I really haven't worried about it as most of the time I tend to shift gear around 3000rpm max anyway, but recently doing a long trip towing a car trailer it was quite a pain not being able to rev just a bit higher before changing up gears.

If I do let the engine rev past 3000rpm it seems to actually pick up power / torque again at around 3400rpm. Which makes me think something is not right, but I have no idea what.



Any suggestions for what I should look at / check?

I have only changed fluids / filters and gaskets to fix leaks on the engine since I have had it, but it has also been serviced twice by landrover specialists so I would have thought they would pick up anything major, but I haven't mentioned it at the times of services as I have needed other things fixed at those times.

[loanrangie]

Sounds a bit like the cam/ pump timing might be out a little bit.

[SSmith]

What he said.

Otherwise, was the turbo replaced or is it original?

If it revs freely without load but struggles with load i suspect trubo or somewhere else in the air system (filter etc)

[mattims]

Not a clue about the turbo being replaced or not. I believe the engine was actually rebuilt by the previous owners dad, or was a rebuilt one he had as a spare. Either way I have no paperwork as to what was done. They did have three defenders other than this one I bought, so I assume they knew a little bit about them.

boost pressure holds pretty consistently at about 13psi all the way to 4000rpm.


What he said.

Otherwise, was the turbo replaced or is it original?

If it revs freely without load but struggles with load i suspect trubo or somewhere else in the air system (filter etc)

[mattims]

I might have a look into the procedure for checking timing. From memory there is a pin that should insert somewhere to verify the pump timing, and cam timing would just be marks on the gears lining up?


Sounds a bit like the cam/ pump timing might be out a little bit.

[Andy130]

Youll need a timing kit - this vid will help on how you do it with the timing cover in place:

Bosch VE Pump timing check with cover plate on - Land Rover 200tdi and 300tdi diesel engines - YouTube (https://www.youtube.com/watch?v=zKnK0kJ1N-o)

[SSmith]

Not a clue about the turbo being replaced or not. I believe the engine was actually rebuilt by the previous owners dad, or was a rebuilt one he had as a spare. Either way I have no paperwork as to what was done. They did have three defenders other than this one I bought, so I assume they knew a little bit about them.

boost pressure holds pretty consistently at about 13psi all the way to 4000rpm.

Not saying they didn't know what they were doing, at those KM if the turbo is original it is possibly just worn out.

A 300Tdi ought to boost to 15 Psi.

Checking the timing with the timing cover on will only tell you if the injection pump is timed, to check the cam timing the cover has to come off.
Yes it is a pin in the injection pump (a drill bit will do the job in a bind - I cannot remember size, sry) and lining marks up on the cam and crank, try a search - there are some very good write ups on the procedure

[Tins]

(a drill bit will do the job in a bind - I cannot remember size, sry)

9mm does it. The pin I have is 9.25mm.

[Tins]

Checking the timing with the timing cover on will only tell you if the injection pump is timed, to check the cam timing the cover has to come off.


If you are going that far then it's madness not to change the belt IMO.

Dave Blknight has a good tute for that. tdi300 timing belt. (https://www.aulro.com/afvb/projects-and-tutorials/133800-tdi300-timing-belt-3.html)

[steveG]

Worthwhile doing simple things like valve clearances and changing the fuel filter first before diving in too deep IMO.
Are you running an EGT gauge? If so what temps are you seeing there?

Steve

[mattims]

Yep I was going to check valve clearances first since it's fairly simple. Its had a new fuel filter at both of it's services so I don't think it's that but it is easy to do so I might just in case.

Yes I have an EGT gauge. The highest temps I have seen are about 600deg (that was pulling a 2T car trailer up hills), usual driving around city is 250-300 and highway at 100-110km/hr is usually around 400-450.



Worthwhile doing simple things like valve clearances and changing the fuel filter first before diving in too deep IMO.
Are you running an EGT gauge? If so what temps are you seeing there?

Steve

[mattims]

well I checked / adjusted the valve clearances and it has made the engine a bit quieter and better at low revs but its still got the same problem just past 3000rpm.

The clearances were all around 0.33 - 0.38mm excpet for 5 and 8 which where ~0.55mm

[loanrangie]

Have you inspected the ic hoses ?