JC 1, Rangieman 0

[justinc]

Just a stir for Chris,(Rangieman)

At 236K pulled a 300Tdi head for a preemptive head gasket replacement as the vehicle is about to do some tripping around, had only 10k or so left in it I reckon, as again, the gasses were creeping under the fire ring at number 4 on their way out to freedom.

So, Chris, Me 1, you Nil,

(Don't forget people,this is supposed to be a tongue in cheek stir, Chris and I go Waaayyy back on this subject...)

As usual, no pics to support my outlandish claims, but customer testimonials can be provided....

JC

[**Discovery300Tdi**]

Just a stir for Chris,(Rangieman)

At 236K pulled a 300Tdi head for a preemptive head gasket replacement as the vehicle is about to do some tripping around, had only 10k or so left in it I reckon, as again, the gasses were creeping under the fire ring at number 4 on their way out to freedom.

So, Chris, Me 1, you Nil,

(Don't forget people,this is supposed to be a tongue in cheek stir, Chris and I go Waaayyy back on this subject...)

As usual, no pics to support my outlandish claims, but customer testimonials can be provided....

JC

Ohhhhhhh come on JC you should know the rules by now!!!!! otherwise no contest i reckon!! lol

[roverrescue]

... but JC if you keep doing pre-emptive head gaskets on 300s then the incidence of blown gaskets will go down and the world will then start thinking that 300s are reliable.

...which will increase their perceived value, therby relatively speaking decrease the market price for other reliable "rover" mechanical diesels...

aha I think I see your plan. Nothing to do with being a good pre-emptive mechanic. Its all about the 4bd1!!!

S

[rangieman]

Ok mate you do know the ing it didnt happen with out pics and proof of life of course , a news paper showing the day and date
I do like your warped sence of humour

[llandro]

Perhaps I just don't get it. (ok. I do about the TIC though!)

A fairly modern type diesel engine and it requires (pre-emptive) head gasket replacement at around 3000 service hours?? no, I am lost here.

My 300tdi Disco is about there now, but from the knowledge I have gained here over a few years I am starting to wonder about the vehicle I thought might just see me out.
So far the only problem has been a leaky rear diff seal, replaced and no further problems, not even oil leaks from the front.

But I did ask a question here some time ago, re: torque on head bolts. The consensous was that because they are angle tightened, torque values do not come into it.

I asked the question because at that time I put a socket on the head bolts (was checking valve clearence) to discover several were not tight, in fact the 10mm. ones were almost loose (about 35ft.lbs.).
This was at around 100k.km., but if the head had shrunk (not very likely), gasket compressed, (even less likely) the bolts stretched (??) how come they were so loose?
No wonder there are head gasket failures or is it purely a design fault?
However, I did crank the buggers up again!

I have to say I am used to earth moving machines where +10/15000hrs. is comonplace before even injectors are looked at.

So why is this bloody 300tdi so sensitive. She is a great vehicle to drive (also own a L/C trayback which IS bullet proof but very harsh on the kidney's), want many more good years service but have to admit a degree of nervousness creeping in as we do travel long distance trips.

Not making a whinge (from an old pom) 'cos have loved Landies since our first 1954 SWB S1.
llandro

[justinc]

Ilandro,

The earthmoving equipment analogy isn't really applicable in this case, most equipment has engines designed for a specific purpose, and designed for a specific service life. These engines are built like solid lumps of cast iron, and most have twice as many head bolts per cylinder area and consequently far less stresses during service.

The Tdi is originally a 2.25 petrol engine block with around 7:1 compression, making this configuration into a relatively high performance high speed turbo diesel engine has worked brilliantly, and is basically way ahead of other designs, even recent manufacturers.

Toyota for example have quite common issues with heads, the B series and H series diesels are chronic precomp chamber and head cracking individuals, and they are NA engines running low outputs. Try running 10psi through a 2H or a 3B and see how long the head gasket and pistons etc lasts.

Even the fantastic Toyota 12HT runs 7psi, the factory Tdi is 14.5 to 15psi, and these engines will see 400 to 500K without bottom end OR head issues, composite head gasket failures are age and material related IMHO, and that is fair enough considering. I rate these engines up there with any, they just need some more cubes to be a real world beater. I haven't even begun to talk about their fuel efficiency yet...


JC

[**Discovery300Tdi**]

Ilandro,

The earthmoving equipment analogy isn't really applicable in this case, most equipment has engines designed for a specific purpose, and designed for a specific service life. These engines are built like solid lumps of cast iron, and most have twice as many head bolts per cylinder area and consequently far less stresses during service.

The Tdi is originally a 2.25 petrol engine block with around 7:1 compression, making this configuration into a relatively high performance high speed turbo diesel engine has worked brilliantly, and is basically way ahead of other designs, even recent manufacturers.

Toyota for example have quite common issues with heads, the B series and H series diesels are chronic precomp chamber and head cracking individuals, and they are NA engines running low outputs. Try running 10psi through a 2H or a 3B and see how long the head gasket and pistons etc lasts.

Even the fantastic Toyota 12HT runs 7psi, the factory Tdi is 14.5 to 15psi, and these engines will see 400 to 500K without bottom end OR head issues, composite head gasket failures are age and material related IMHO, and that is fair enough considering. I rate these engines up there with any, they just need some more cubes to be a real world beater. I haven't even begun to talk about their fuel efficiency yet...


JC

OOHHhhhhhhhh stop talking technical and wheres the proof???????

[LandyAndy]

JC
Roothy will do a trip to Tassie to lynch you if he reads that.
Best barricade the workshop with your flash tojos,he may re-consider when he gets there
Andrew

[llandro]

JC.
I really have to take you to task on your reply.
Yes, I aknowledge your reputation with Landrover repair and maintenance but please have a re think over your comments.
Such as "most equipment has engines designed for a specific purpose and specific engine life"

So what the hell is the 300tdi? A throwaway meccano toy motor?

And you say the tdi is originally the 2.25 petrol engine block with 7:1cr.
Beg pardon, but I have a '76 2.25 diesel with 23:1cr and it was at the end of its capability.
It required 5 main bearings and much more to sustain it into its present form.

With your comparison of the 12ht and the tdi, well yes there is some difference in the turbo boost but both utilise composite head gaskets. Gasket failure on any Toyota diesel, N/A or factory turbo, is very rare indeed. (not counting low coolant etc.)
Tdi.,Td5 head gasket failure seems commonplace or part of PM.

Our 30t. Komatsu excavator has a 4l. turbo engine rated at 96kw. (2250rpm) It has no more head bolts than most other 6cyl. tubo diesels, has now over 9000hrs. on the clock and uses around 15l./hr. fuel.
It is not a "solid lump of cast iron" but a lightweight, efficient and economical diesel built in 1989. Very comparable to most present day diesels.

My concern is that instead of a long living, reliable diesel engine (which it has been so far) I am faced with such issues as sudden head gasket failure ("age and material related") when it should never be even thought about.
I can live with general engine wear (rings/bores/bearings etc) even alternator, vacuum pump, gearbox noises.... but head gasket?

For my final thought we are in complete agreement. As a Mech.E.(retd.) I do have some understanding of "things mechanical" and I have also made several adjustments to the fueling regime of my 300tdi.
She is still well capable of 160kph. and on a long trip returns an ave. of 9.6l./100km.
llandro

[justinc]

JC.
I really have to take you to task on your reply.
Yes, I aknowledge your reputation with Landrover repair and maintenance but please have a re think over your comments.
Such as "most equipment has engines designed for a specific purpose and specific engine life"

So what the hell is the 300tdi? A throwaway meccano toy motor?

And you say the tdi is originally the 2.25 petrol engine block with 7:1cr.
Beg pardon, but I have a '76 2.25 diesel with 23:1cr and it was at the end of its capability.
It required 5 main bearings and much more to sustain it into its present form.

With your comparison of the 12ht and the tdi, well yes there is some difference in the turbo boost but both utilise composite head gaskets. Gasket failure on any Toyota diesel, N/A or factory turbo, is very rare indeed. (not counting low coolant etc.)
Tdi.,Td5 head gasket failure seems commonplace or part of PM.

Our 30t. Komatsu excavator has a 4l. turbo engine rated at 96kw. (2250rpm) It has no more head bolts than most other 6cyl. tubo diesels, has now over 9000hrs. on the clock and uses around 15l./hr. fuel.
It is not a "solid lump of cast iron" but a lightweight, efficient and economical diesel built in 1989. Very comparable to most present day diesels.

My concern is that instead of a long living, reliable diesel engine (which it has been so far) I am faced with such issues as sudden head gasket failure ("age and material related") when it should never be even thought about.
I can live with general engine wear (rings/bores/bearings etc) even alternator, vacuum pump, gearbox noises.... but head gasket?

For my final thought we are in complete agreement. As a Mech.E.(retd.) I do have some understanding of "things mechanical" and I have also made several adjustments to the fueling regime of my 300tdi.
She is still well capable of 160kph. and on a long trip returns an ave. of 9.6l./100km.
llandro

JC.
I really have to take you to task on your reply.
Yes, I aknowledge your reputation with Landrover repair and maintenance but please have a re think over your comments.
Such as "most equipment has engines designed for a specific purpose and specific engine life"

So what the hell is the 300tdi? A throwaway meccano toy motor?

And you say the tdi is originally the 2.25 petrol engine block with 7:1cr.
Beg pardon, but I have a '76 2.25 diesel with 23:1cr and it was at the end of its capability.
It required 5 main bearings and much more to sustain it into its present form.

With your comparison of the 12ht and the tdi, well yes there is some difference in the turbo boost but both utilise composite head gaskets. Gasket failure on any Toyota diesel, N/A or factory turbo, is very rare indeed. (not counting low coolant etc.)
Tdi.,Td5 head gasket failure seems commonplace or part of PM.

Our 30t. Komatsu excavator has a 4l. turbo engine rated at 96kw. (2250rpm) It has no more head bolts than most other 6cyl. tubo diesels, has now over 9000hrs. on the clock and uses around 15l./hr. fuel.
It is not a "solid lump of cast iron" but a lightweight, efficient and economical diesel built in 1989. Very comparable to most present day diesels.

My concern is that instead of a long living, reliable diesel engine (which it has been so far) I am faced with such issues as sudden head gasket failure ("age and material related") when it should never be even thought about.
I can live with general engine wear (rings/bores/bearings etc) even alternator, vacuum pump, gearbox noises.... but head gasket?

For my final thought we are in complete agreement. As a Mech.E.(retd.) I do have some understanding of "things mechanical" and I have also made several adjustments to the fueling regime of my 300tdi.
She is still well capable of 160kph. and on a long trip returns an ave. of 9.6l./100km.
llandro

Well yes I do agree with your reply, especially the ser3 diesel, as I had forgotten they run well over Tdi compression ratios, and yes they are a pretty forgiving engine with a cast iron head, although that really has no bearing on the gasket longevity. (They are also Indirect injection IIRC ?)
The original comment was that I have seen lots of Tdi head gasket failures at these km, but quite a few that have gonbe a lot further, too. As Rangieman will attest to we have had our differences of opinion as to whether to change out the gasket as a preventative measure, rather than have it dictate to YOU when it is going to fail.

I'm not very expert in the heavy machinery side of things, but I would say that although they are under a fair amount of strainthey would want to have very large safety and longevity margins for engine life, IE lower RPM's, lower boost pressures and consequently conservative fuelling and EGT's for these reasons. They have a fair amount of operator abuse failsafes too don't they? I agree they are still working hard but the average mega dollar piece of earthmoving equipment would want to be ultra reliable in the field, therefore running at way less than its 'design stresses' in order to be reliable and efficient, for longer which I would say is a big consideration when buying one.

The incidence of head gasket failures in Td5's IMHO restricts itself to overheated examples, especially those with plastic locating dowels in earlier models. The Tdi is quite reliable in this department really, I have a few with 350 to 450K that are running like clockwork, my suggestion of 240 to 260K head gasket replacements is purely that, a suggestion based on the frequency of failures I have observed in the business over the last 10 years working specifically with these engines, but there are just as many without faults. This is where Chris (Rangieman) and I have our 'disagreement'

So yes, they are a great engine, I feel there are a few areas to look at to ensure long life, but treated well they will see huge KM .



JC (Assoc.Dip.Mech.Eng, hoping to retire eventually...)