Cold diesel engine vs warm - difference in sound

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LRD90tdi

LRD90tdi

New Member
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Location
Somerset
Hi all,

I've read various threads about tappets getting noisy etc but want to know how many of you can really notice a significant difference in noise after 10 miles once your derv has warmed up?

My 200 tdi sounds fine after 5-10 miles, but it is a bit da da da da da under load while it warms up - to the point I am very, very gently (just being kind, it isn't 'that bad') for a few miles....

If you didn't point it out, a non petrol-head passenger might not even notice, but I hear it every time clear as day.

Is this normal??

Thanks
Tom
 
I know it's a different diesel engine, but with the D2 TD5 engine there's a noticeable difference in rattle from cold to warm when under load. I notice it fades out as the engine gets warmer: you only hear it as you use more throttle, until the point at which the engine's warmed up enough so that there's no difference under load whatever throttle setting you use.
 
Yep my 2.5na diesel fender definitely has more of a 'rattle' at cold, it still does it when hot but it's less 'harsh' if that makes sense
 
All engines rattle more when cold, just new ones are so wrapped in plastic you cant hear it
older ones more so, as everything warms up gaps and tolerances close up a bit hence why you do tappets when its cold (on a defender anyway, some engines need to be warm) to set them correctly, as the gap changes when it warms.
Deisels especially rattle a bit more because it takes ever so slighly longer for a complete burn till everything warms up.
 
Next time you stir sugar (assuming that you use sugar) into your tea/coffee, listen to the way that the note deepens. It's the cup becoming less dense. So not only tolerances closing and opening, but the whole thing softening in effect.
 
The diesel knock will be less when warmed up as well because the engine is more efficient, knock should almost go away when the engine is running at peak performance.
 
In response to expansion of components and tolerances: I'm pretty familiar with engines and have a (much unused to be fair) bsc in engineering, but I've had diesels for years - admittedly not LR's, but, if it is just diesel knock, it has never been so pronounced.

I wonder if my top end clarences are just on the limit of tolerances which allow them to be acceptable when hot, but too large when cool exacerbating the noise...

Besides the forum I'm not yet in a Landy scene so have no other 200/300 to compare against.

Cheers
Tom
 
Last edited:
LRD90tdi said:
Hi all,

I've read various threads about tappets getting noisy etc but want to know how many of you can really notice a significant difference in noise after 10 miles once your derv has warmed up?

My 200 tdi sounds fine after 5-10 miles, but it is a bit da da da da da under load while it warms up - to the point I am very, very gently (just being kind, it isn't 'that bad') for a few miles....

If you didn't point it out, a non petrol-head passenger might not even notice, but I hear it every time clear as day.

Is this normal??


Thanks
Tom
Click to expand...

yes
How long do you let it warm up before you drive off?
 
LRD90tdi said:
In response to expansion of components and tolerances: I'm pretty familiar with engines and have a (much unused to be fair) bsc in engineering, but I've had diesels for years - admittedly not LR's, but, if it is just diesel knock, it has never been so pronounced.

I wonder if my top end clarences are just on the limit of tolerances which allow them to be acceptable when hot, but too large when cool exacerbating the noise...

Besides the forum I'm not yet in a Landy scene so have no other 200/300 to compare against.

Cheers
Tom
Click to expand...

All diesels when cold sound like a bucket of bolts getting shaken


http://www.fev.com/fileadmin/fev-re...Systems/2005-01-2490_DieselColdStartNoise.pdf
 
In this mild weather, I don't leave it more than 30 seconds, but my revs would not exceed (at a guess) 1750rpm for a mile or so.


Tom
 
I'm going to record it after reading back your posts - it is more da da da da than rattle as if everything was loose and it sounds fine on tick over.

Tom
 
Thor1950 said:
give 3-4 minutes will be easier on the engine, less wear and tear, and better mpg
Click to expand...

thor,this is an exerpt taken from an American gov site,Indiana.





  • Myth: Diesel engines need to idle for 5 minutes or more in the morning, especially on cold days.
    • Fact: This is one of the most commonly held myths in North America concerning diesel engines. Most engine manufacturers recommend that newer diesel engines run for no more than 3 minutes before driving.
    • Gelling of diesel fuel used to be a problem, but refiners have worked to resolve this issue by creating winter blends that better withstand colder temperatures.
    • Letting an engine idle actually does more damage to the engine than starting and stopping. Running an engine at low speed (idling) causes twice the wear on internal parts compared to driving at regular highway speeds, which can increase maintenance costs and shorten the life of the engine.
    • Please check your owner's manual to find out specific warm-up guidelines for your vehicle.
 
gemsdad said:
thor,this is an exerpt taken from an American gov site,Indiana.





  • Myth: Diesel engines need to idle for 5 minutes or more in the morning, especially on cold days.
    • Fact: This is one of the most commonly held myths in North America concerning diesel engines. Most engine manufacturers recommend that newer diesel engines run for no more than 3 minutes before driving.
    • Gelling of diesel fuel used to be a problem, but refiners have worked to resolve this issue by creating winter blends that better withstand colder temperatures.
    • Letting an engine idle actually does more damage to the engine than starting and stopping. Running an engine at low speed (idling) causes twice the wear on internal parts compared to driving at regular highway speeds, which can increase maintenance costs and shorten the life of the engine.
    • Please check your owner's manual to find out specific warm-up guidelines for your vehicle.
Click to expand...

correct, at idle the oil pressure is low, driving the oil pressure is higer, just dont thrash it till its warm.
I leave mine 5/10 secs (about as long as it takes to put my seatbelt on) its long enough to let oil pressure come up and oil to get round the engine.
 
Thor1950 said:
All diesels when cold sound like a bucket of bolts getting shaken


http://www.fev.com/fileadmin/fev-re...Systems/2005-01-2490_DieselColdStartNoise.pdf
Click to expand...

My 2012 VW Beetle with the 2.0 common rail TDI engine doesn't. Sounds much the same hot or cold (very quiet!).

My 200tdi defender is noisier cold but that's normal for older Diesels. I start it and drive off after maybe 10 seconds. As has been said leaving it to idle and warm up is a waste of time and could be damaging to the engine and a waste of fuel!

Every car I've had states start and drive, don't leave it idling to warm up.
 
harry2012 said:
My 2012 VW Beetle with the 2.0 common rail TDI engine doesn't. Sounds much the same hot or cold (very quiet!).

My 200tdi defender is noisier cold but that's normal for older Diesels. I start it and drive off after maybe 10 seconds. As has been said leaving it to idle and warm up is a waste of time and could be damaging to the engine and a waste of fuel!

Every car I've had states start and drive, don't leave it idling to warm up.
Click to expand...

Does the 200 sound 'knocky' or is it just a general higher level of noise?

Thanks
Tom
 
gemsdad said:
thor,this is an exerpt taken from an American gov site,Indiana.





  • Myth: Diesel engines need to idle for 5 minutes or more in the morning, especially on cold days.
    • Fact: This is one of the most commonly held myths in North America concerning diesel engines. Most engine manufacturers recommend that newer diesel engines run for no more than 3 minutes before driving.
    • Gelling of diesel fuel used to be a problem, but refiners have worked to resolve this issue by creating winter blends that better withstand colder temperatures.
    • Letting an engine idle actually does more damage to the engine than starting and stopping. Running an engine at low speed (idling) causes twice the wear on internal parts compared to driving at regular highway speeds, which can increase maintenance costs and shorten the life of the engine.
    • Please check your owner's manual to find out specific warm-up guidelines for your vehicle.
Click to expand...

take your myth and ............ New diesels have a automatic fast ideal in cold weather starts, to over come low oil pressure, and some even had a hand throttle to do a fasts idle, 1000rpm ;)
 
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