I’m new to landyzone although I have been on the defender forums a while !! Td5 knock??

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Deftd506

Deftd506

Member
Posts
26
Location
Gloucestershire
My 90 td5 has developed a knock at idle when hot, Any ideas?

It’s really driving me mad!!

Injectors?
Crank pulley has been replaced




Cheers

Alex
 
It’s strange how I have never noticed it before. I am mechanically minded but do appreciate it’s an old diesel! However I know or like to think I know the normal Td5 sounds having owned them since I started driving.. this one has only done 80000 miles I have a 140k truck which sounds much smoother ??
 
They all sounds the same to me:oops: sorry. Well except my V8:)

Anyway.

Welcome to this forum:)

Possibly better to ask in the tech treads it will get more lookers:)

J
 
Cheers!

I think my 06 90 in the first clip has a much harsher diesel knock, I have compared it to many others.

No the manifold has never been off or touched. 5w30 Morris.

I think the majority will recognise if their car makes a different sound to normal? Mine hasn’t changed over night but I’m 99% sure it become much heavier.

I have ordered a good known set of injectors, I will give these a go.

Cheers

Alex
 
Hi,

you are not alone! I got the TD5 with Diesel in oil, so i changed the head immediately (AMC). Because of this, i didn't know the sound of the TD5 before. Injectors are reconditioned.

I'm also little bit nervous about the knocking sound. I've made two videos, one warm and one cold.




It's best to hear it with real speakers, on some smartphones you can't hear the knocking.

I know from one another TD5 which was completly overhauled and had this knocking sound too.

When the TD5 stoods some days, it needs 1 second to run even. But besides of that and the sound everthing is OK....but i really want to know from where this knocking comes...

Best Mario
 
We had two TD5 Defenders at the same time, a 2003 90 and a 2005 110.

The 90 had done 120,000 and was a smooth as silk.
The 110 was on 56,000 and was positively rough in comparison, so much so that l considered a sneaky engine swap while my missus was away (hers was the 90)

Anyhow, the 90 has been sold as it was too expensive running two Defenders as daily drivers but l still have the 110. Now on 112,000 the engine has become as smooth as the 90 was.
 
Mario

I can hear the knock from your Td5, it does sound very similar to what mine makes.

My dipstick level hasn’t risen. So I’m confident there is no diesel is in the oil. Mine has never been touched except for injectors seals two years ago as a precaution for a long trip. It’s currently on 82,000 miles.

Perhaps one of the injectors, I know a lot a diesel specialist are unable to test Td5 injectors?

What have you checked, who done the head swap ?

Thanks

Alex
 
Head swap was done by a guy who is specialized on Defender and other Land Rover. Additionally the following parts were exchanged: Hydraulic lifters, glow plugs, chain tensioner, Diesel pump, fuel pressure regulator, air flow meter, small harness and the injectors.

The injectors were a pain! I've sent them to a company which are tricked me with replicate parts (not Delphi) and wrong nozzles. After I got my money back, I buyed 5 “new” injectors refurbished at Delphi/Land Rover (some injector parts are available again from Delphi). The interesting part is, I had this knocking sound also with the faulty injectors. The main issue with the faulty ones was, unsteady idle, misfire and smoke. (https://www.landyzone.co.uk/land-rover/unsteady-rev-mainly-in-idle.346284/)

Now with the new injectors, the cylinder balance looks better: When it's cold and smoother the values are higher, when it's warm and noisy, the balance is better - strange. On the other hand, cylinder balance was with the faulty injectors also in tolerance -7/7.

The other TD5 which I was mention, was done by another mechanical, he got his injectors from another dealer. There some overlapping in procedure we have done, like head from AMC, programming the new injectors with the Nanocom, new tensioner, injector seals. Maybe the order is wrong in injector programming or we have done the wrong procedure calibrating the rocker shaft/injector. Currently, I did not have any other idea what to check...

Do you have your knocking sound since changing the injector seals? If yes, this narrow down the issue....
 
Im not sure, It’s possible it could have started since the seals were replaced however I cannot be certain.

To be honest this one has always been a little harsher than my other Td5. I bought it with only 57,000 miles on the clock and always thought it would run smoother as time goes on. Previous owner only done 4,000 a year in it.

I would double check the injector rocker adjustments. Maybe just do them again?

I’m swapping my injectors incase. I will update you once completed.

I will agree it does cause some anxiety while driving especially long distance.
 
Most people are saying this sound is OK but the uncertainty remains.

Another theory is that it has something to do with the pilot injection. I know the TD5 is doing this and the last digit of the injector code is for idle speed correction. Maybe this value "moves" while operating temperature changes and in warm condition and doesn't fit. The pilot injection will be disabled above a certain rev speed, so while driving it doesn't matter (I think). It would be nice to have more details about this topic.

upload_2019-8-12_9-34-9.png


When you have a look at the waveform of the audio files, you can see that one ignition is causing the sound. I've an oil stop in the loom....so it's easy to pin out the injectors while running - but I'm not sure if this is a good idea. I don't want to destroy the ECU or injector....has somebody do this before while engine is running?

I'm not a diesel engine developer/expert - only a software engineer for ECUs but not for motor ECUs :-( So everything I said above are assumptions....
 
I think this procedure can be valid if you know which cylinder is currently knocking. Then you can check if knocking moves with the injector or not.
 
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