Hey Darmein,
your original posts indicated that you were absolutely certain that the noise was engine RPM matched and definately not road speed.
Kinda threw us all.
You and me also Mark2. To be perfectly honest I'm still have no clear idea what is causing this problem.
{Thought dump}.
I would love to be able to load test the engine without the transmission to prove the engine one way or the other. That an't going to happen. So I've stopped treating the car like a wounded animal and am driving it quite hard now and its going like a rocket. I can't believe this is the performance of a damaged engine.
The original symptoms still stand, a hammering noise when under power. Its not gear related, the engine appears to be running as good as it always has. Its not loosing oil or water, there is no smoke at all, it starts well hot or cold. The engine oil was changed and the old oil was free of anything suspisious. The timing belts are in reasonable condition and, now I've got the covers off (and they are still off, waiting for a belt change) I find they are tensioned correctly.
Yet the noise is still there and appears to be at the same or similar frequency as the engine firing speed. It is getting louder, and I mean loud, and I think the problem will show itself in the not too distant future. I can feel vibration in the drivers seat and that is getting worse also, I can feel it in the gear stick but not in the handbrake. That vibration was not there before this problem appeared. It seems to be lower and forward of the driving position. Its not affected by steering. It is prominent from 30 to 50 MPH. It reduces at high speeds, as in 60 and above. It quietens down when the power is taken off BUT and this is a big BUT, at higher speeds (50ish) and going down hill, if I deck the clutch and cut the throttle I can still hear some of the noise.
What is spinning at 2000 RPM in the transmission at the 50 MPH? If that question can be answered then we might have a clue. The question that is now crossing my mind (and I know I must have suspected about every part of this bloody car in the last few weeks) is it the IRD??? Clue, when I bought the car and didn't know the problems these things have with the transmission, I inspected the underside on the lift and it was immediately apparent that it had a new VC and support bearings, as in brand new, they were spotlessly clean. Now why would someone sell a car after investing several hundred pounds in it?? That was a year ago. Is the IRD now giving up??
I spent this lunchtime crawling around the engine bay inspecting the exhaust system from manifolds to down pipe. No sign of a leak. I fired up the engine and quickly ran my hands around the gaskets before it got too hot. Nothing found. That is how stumped I am to identify this problem.
I am very tempted to find a garage that is selling another L series and take it for a test drive to see what the difference is.
I am an engineer by trade, I realise I am not that familar with the design of this car (although I'm getting to know it very well now
) but I am confident with working on cars, how they work, the types of problems and how to fix them. This one has got me completely stumped and its got three others with ideas but no firm diagnosis. The reason is you need to be in the engine bay at 50 MPH.
My reasoning for posting on this site is two fold. First to share with other landrover enthusiasts the problems that I am having so you may be able to draw on whatever I eventually discover is the problem. Secondly, that there is the possibility that someone out there may say 'I know what that is'. There have been several postings with good ideas and I am grateful for every one of them.
I'm sorry if it is felt I have misled you, I didn't intend to and I make my best efforts to report the facts. Those facts are now changing because whatever is wrong is getting worse and I am wondering how long it is before I need my AA membership card to get home. When that happens I will gladly report what has happened, what needs replacing and any information that you can use to protect your cars from suffering a similar fate.
Having said all that I have to say the Freelander is still the most fun car I have owned and I am intending to get to the bottom of this problem and then have some fun with it.
Thanks for listening,
Dave