I need some Advice on TD5 big end or main bearing knock,

[freefall1]

Hi guys ,I need some advice on what to do next,I got my TD5 this time last year and as given trouble from the start.The main problem was a cracked head(Diesel in Oil)the engine blew a piston one night on the way home,Thankgod i was only doing 15mph and 200 feet from my front door when it happen.The garage took it back and put a new head and five new piston heads so they say, And told me to keep it under 60mph for first 1000km,To give pistons time to bed in!!!!Which i did.There is a new head on it ,But i d,ont think they put the five piston heads in ,One maybe.It drove well for the first few months and then one night again coming home from work the whole truck slowed up.It was like i was pulling something very heavy and bad diesel knock with vibrations came into it.I then desided to drop gear box out ,because dual mass can cause that problem.This is a list of things i have done so far,New dual mass ,New clutch kit and clutch fork,New gear box oil,New injector loom,EGR bypass kit,De-cat the front pipe and a mid straight exhaust pipe. Injectors had wrong codes on them when i took rocker cover off so used nanocom to match with ECU codes.The truck drives better now ,but still as a old diesel type knock to it.The thing is you could leave it on idle for a half hour and not a sound,Even if you rev it up on idle, Sounds normal,Its only when you drive it you get that engine knock.I am now thinking that it must be main or big end bearings ,Because diesel in the oil washed white metal from them .I know that i will end up putting in a second hand engine at some stage in.But at the moment can,t not afford to do so .My ? is i am thinking of putting in a heavier oil in 10w40 part synthetic,I have 5w30 in it at the moment.If it gives me a few months more running.The jeep is a 2004 defender 90 with 92,000miles on it .Any advice welcome,Thanks lads for taking the time to read this,Regards brian.

[Les Henson]

Main bearings will rumble all the time, big ends will knock only when the engine is under load (pulling away, high gear uphill, etc). You might save the engine if the shells are not too badly worn - continued use will damage the crank eventually.

Les.

[freefall1]

Thanks Les for info .I might drop the sump and have a look,The nanocom is showing a imbalance in number 4 cylinder of -11 and number 5 cylinder -17.The first three seem to be ok .The truck has lots of power no blue smoke from tail pipe and drives good otherwise.

[Les Henson]

Worn big end or main bearings will give you lower oil pressure, but that's all - no smoke, and a barely notiveable drop in engine performance. That is - until it goes bang

Thicker oil might help, but not as much as you might think.

Les.

[pat_pending]

You said in your first post that it had a "old diesel type knock". This can be caused by one or more injectors blowing off early and wont necessarily cause noticeable smoke. This also could tie in with the two cylinder imbalances you're getting. Try swapping the injectors from the offending cylinders with two good cylinders, recode them in and re check to see if the imbalance has followed the injectors or stayed on the same two cylinders.

[freefall1]

Thanks Les & Pat for the sound advice you given me,The truck has been off the road now for last 5 months while i was working on it with clutch,Flywheel etc..So will leave it that way until i investigate the problem more.Both answers have given me hope that i will get it back on the road.Regards Brian.

[freefall1]

Hi Guys,Only got two working on the defender in the last two days,Its been off the road for 12 months now,And* Les* you were right on the money with the big end shells,All the top shells were down to copper,The bottom shells have lots of white metal ,The crank has no real scoreing on it a few light marks,But smooth to the touch,I put the new shells in and use 10w40 oil in stead of the 5w30 ,I then took it out for a drive and the heavy knocking is gone,But time will tell if the crank is ok,Heres some Photos.

[Jakob]

Hi Guys,Only got two working on the defender in the last two days,Its been off the road for 12 months now,And* Les* you were right on the money with the big end shells,All the top shells were down to copper,The bottom shells have lots of white metal ,The crank has no real scoreing on it a few light marks,But smooth to the touch,I put the new shells in and use 10w40 oil in stead of the 5w30 ,I then took it out for a drive and the heavy knocking is gone,But time will tell if the crank is ok,Heres some Photos.

Hi!

I have the same problem I think. How did you do it? Could you change the bearings with the engine still in the car?

/Jakob