TD5 versus M51

This site contains affiliate links for which LandyZone may be compensated if you make a purchase.
Datatek said:
Never seen any smoke out of mine even reving to the limit in second up an Alp:)
Click to expand...

Its not smoke as such, I presume its just the general build up of carbon in the exhaust system that gets cleared out at high gas flow/temperature through the system, could be the catalyst cleaning itself (if fitted?).

Possibly a bit of over fueling at the very top end due to wear, as far as I know the injection systems never been touched set up wise on my engine.

And of course Datatek you don't have the luxury of London style traffic down your way....;)
 
Last edited:
I hated diesels with a passion........untill I bought my P38 td.......its impressed me no end, quick for a large brick and frugal with it too
 
zzr1200 said:
Its not smoke as such, I presume its just the general build up of carbon in the exhaust system that gets cleared out at high gas flow/temperature through the system, could be the catalyst cleaning itself (if fitted?).

Possibly a bit of over fueling at the very top end due to wear, as far as I know the injection systems never been touched set up wise on my engine.

And of course Datatek you don't have the luxury of London style traffic down your way....;)
Click to expand...
Yep, unless we go to Paris, it rarely crawls in traffic.:):)
 
Moron said:
I hated diesels with a passion........untill I bought my P38 td.......its impressed me no end, quick for a large brick and frugal with it too
Click to expand...

Diesels are fine for tractors, lorries and proper utility vehicles - but why sully a luxo-barge with one?
 
Datatek said:
In the case of the P38, because they are economical, reliable and don't slip liners:p:)
Click to expand...

Some people don't care about economy (me included) and would much rather have the smoothness and power of a V8 over an oil-burner - as for reliability there seems to be plenty of broken diesels on here - and other than in the world of the internet I've yet to actually experience a P38 with slipped liners. I know a couple of chaps that - like me - rack up thousands of miles in a V8 P38s without any major dramas. I think you only see the worst of any car on forums - people don't hunt out internet forums to post how reliable their car has been! Most Rover V8s die from being driven for thousands of miles with a knackered camshaft (often fro neglected oil changes) - the swarf from which damages the rest of the engine. Of course slipped liners do happen (allegedly) - coz I've still yet to see one with my own eyes! ;) I think the M51 is more negligence-proof, but when well-maintained both can last a reasonably long time.

Back to the post(ish), the TD5 was an excellent engine which never received the development budget it deserved - I think it's better than the M51, but then so were the later BMW units.
 
StuckAgainSteve said:
Some people don't care about economy (me included) and would much rather have the smoothness and power of a V8 over an oil-burner - as for reliability there seems to be plenty of broken diesels on here - and other than in the world of the internet I've yet to actually experience a P38 with slipped liners. I know a couple of chaps that - like me - rack up thousands of miles in a V8 P38s without any major dramas. I think you only see the worst of any car on forums - people don't hunt out internet forums to post how reliable their car has been! Most Rover V8s die from being driven for thousands of miles with a knackered camshaft (often fro neglected oil changes) - the swarf from which damages the rest of the engine. Of course slipped liners do happen (allegedly) - coz I've still yet to see one with my own eyes! ;) I think the M51 is more negligence-proof, but when well-maintained both can last a reasonably long time.

Back to the post(ish), the TD5 was an excellent engine which never received the development budget it deserved - I think it's better than the M51, but then so were the later BMW units.
Click to expand...

blocks cracking behind liner is/was a very real issue,some on new cars some only when cooling system had become less effective
 
jamesmartin said:
blocks cracking behind liner is/was a very real issue,some on new cars some only when cooling system had become less effective
Click to expand...

I believe (dunno if it's internet mythology) that there were many NOS 3.5 blocks machined by different outside suppliers to become 4.6s. Some go and some don't.

Of course if Rover had taken a leaf out of Buick's book and cast keyed liners into the blocks instead of pressing them in the cheap-skate way - or at least used tophat liners when they stroked the engine to the point where they ran out of metal around the base of the liners - none of the issues would have happened! :(
 
StuckAgainSteve said:
I believe (dunno if it's internet mythology) that there were many NOS 3.5 blocks machined by different outside suppliers to become 4.6s. Some go and some don't.

Of course if Rover had taken a leaf out of Buick's book and cast keyed liners into the blocks instead of pressing them in the cheap-skate way - or at least used tophat liners when they stroked the engine to the point where they ran out of metal around the base of the liners - none of the issues would have happened! :(
Click to expand...

factory engines from 3.9 on suffered, though you can alter 3.5 to 3.9 by taking out an extra 200 thou and fitting wider liner ,which is why they are susceptible to cranking, though i do know a lot of engines 3.5s were converted by the place i used to work at after i left sold a lot to rpi and others ,fitted to ni police lrs that were done very badly , i believe a lot of them failed
 
fortgrange said:
I thought new Defenders had the Transit 2.2 TDCi engine?

Although I do think there are some rose coloured specs being worn. I must confess I've never driven a fettled diesel P38, but having driven many with standard issue have found the TD5 to be a much nicer unit.
Click to expand...
The op said new not when :p

Bix said:
Mine makes an interesting smoke screen that is only really visible at night when I absolutely nail it. During the day it cannot be seen, but once it gets dark out and the lights are on. No doubt something expensive is wrong.

But she goes well, I've taken many the nob at traffic lights without really trying and the motor does sound lovely when you're putting some load in it, going up a hill for example. Just makes me yearn for a V8 though. :(
Click to expand...
I get that in the dark against the oncoming headlights nothing to worry about

As for that latter paragraph , I don't do nobing at traffic lights :)
 
I've got a m51 p38 with over heating problems
Is it likely that I've already damaged the cylinder head by it over heating
Regardless of the cause of the cooling problems ?
I understand air locks are a common issue on the diesel p38 , I'm going to chase the normal is
But just trying budget for worst case scenario, ie head gasket/cylinder head work, and potential damage to rest of engine if and when it's opened up .
Any help/ advise would be greatly appreciated
 
p38DH said:
I've got a m51 p38 with over heating problems
Is it likely that I've already damaged the cylinder head by it over heating
Regardless of the cause of the cooling problems ?
I understand air locks are a common issue on the diesel p38 , I'm going to chase the normal is
But just trying budget for worst case scenario, ie head gasket/cylinder head work, and potential damage to rest of engine if and when it's opened up .
Any help/ advise would be greatly appreciated
Click to expand...
An overheat does not necessarily mean the head is stuffed, mine overheated when the water pump failed and is OK still.
A replacement head would be quicker, cheaper and easier than fitting a TD5 lump, think of all the electronic problems.
Airlocks have never presented a problem when I change the antifreeze, I raise the front of the car and rapidly squeeze and release the top hose for the final top up with the engine idling, as long as the bleed pipe is clear it's easy.
 
Oh that's encouraging ,
Is a head replacement too much to diy
My local garage won't touch it
Said its to much hassle
I'm also in a rural area so not sure where I could take it if it is head gasket.
I only ask as on another forum there was a thread and people were saying it's major work as once you get in to the engine you could have slipped liner s and lots of trouble .
Is this mainly an issue with the v8 , is the diesel a more robust unit ?
 
I know the bleed pipe is clear I checked so thanks for the info .
Hopefully it will be sorted I've order a thermostat, water pump new radiator and new header tank
If it is the head ill have to learn on the job
 
p38DH said:
Oh that's encouraging ,
Is a head replacement too much to diy
My local garage won't touch it
Said its to much hassle
I'm also in a rural area so not sure where I could take it if it is head gasket.
I only ask as on another forum there was a thread and people were saying it's major work as once you get in to the engine you could have slipped liner s and lots of trouble .
Is this mainly an issue with the v8 , is the diesel a more robust unit ?
Click to expand...
Slipped liners are a V8 problem. The only real weak spot on the M51 is the cylinder head doesn't like overheating. As far as I'm concerned, head gasket replacement (which rarely fails) or head replacement is a DIY job.
 
p38DH said:
I know the bleed pipe is clear I checked so thanks for the info .
Hopefully it will be sorted I've order a thermostat, water pump new radiator and new header tank
If it is the head ill have to learn on the job
Click to expand...
Check the viscous fan is OK, it's a major cause of overheating.
Check any new thermostat in a pan full of boiling water before fitting it, there are a lot of dodgy ones on the market, also it should have a bleed hole which should be located at the top.
 
p38DH said:
Oh that's encouraging ,
Is a head replacement too much to diy
My local garage won't touch it
Said its to much hassle
I'm also in a rural area so not sure where I could take it if it is head gasket.
I only ask as on another forum there was a thread and people were saying it's major work as once you get in to the engine you could have slipped liner s and lots of trouble .
Is this mainly an issue with the v8 , is the diesel a more robust unit ?
Click to expand...
If you a capable with tools just follow Rave and it's straight forward
 
jamesmartin said:
factory engines from 3.9 on suffered, though you can alter 3.5 to 3.9 by taking out an extra 200 thou and fitting wider liner ,which is why they are susceptible to cranking, though i do know a lot of engines 3.5s were converted by the place i used to work at after i left sold a lot to rpi and others ,fitted to ni police lrs that were done very badly , i believe a lot of them failed
Click to expand...
And of course there was also the issue of LPG usage where the higher combustion chamber temperatures could accelerate the block cracking/slipped liner scenario .. believe me I've been there, together with a friend with another 3.9 similarly converted.
 
You must log in or register to reply here.

Similar threads

alexmcrobbie
P38A M51 to Rover V8 Swap?
Replies
16
Views
2K
Grrrrrr
Grrrrrr
F
P38 DSE loss of power when driving
2
Replies
33
Views
1K
Mark Piercy
Mark Piercy
D
Td5 defender vibration
Replies
11
Views
350
bankz5152
bankz5152
Globetreka
300Tdi or Td5?
Replies
2
Views
275
tottot
tottot
I
Automatic Gearbox and hand controls.
Replies
3
Views
297
Stanleysteamer
Stanleysteamer
Back
Top