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

[Deftd506]

Let me know how you get on with yours. What’s your next plan of attack ?

 

[Mario110]

Sure. Next thing is to identify the cylinder which is knocking - I'm really interessted in even though the car is running....
Question is if it's possible to pin out injector by injector while engine is running, if this doens't damage the ECU or injector...
Before that i will try other possibilitys:
- There are Apps for measure vibrations (https://appcenter.bosch.com/details/-/app/iNVH), maybe i can see a peak/diff while pressing the phone on the valve cover cylinder by cylinder
- Checking the ECU with my oscilloscope if pilot injection is triggered, just to if there is some difference
Let's see...easiest way is to pin out but there are some concernes about that and i didn't know if this is useful when engine is running odd because of a missing injection...

I've found this video yesterday, this is really nice...

 

[Deftd506]

Mario

Fitting the replacement injectors hasn’t cured the knock.

Mine only does it when the engine is hot?
From cold it’s silky smooth until warmed up.

I’m not entirely sure what to do next?

 

[Discodevon]

Mario

Fitting the replacement injectors hasn’t cured the knock.

Mine only does it when the engine is hot?
From cold it’s silky smooth until warmed up.

I’m not entirely sure what to do next?

Get the exhaust manifold skimmed

 

[Deftd506]

Get the exhaust manifold skimmed

Why.. I guess it’s a possibility due to it being temperature related. However I’m pretty sure if the manifold was warped it would make a high pitch squeal on acceleration ?

It also appears to make the noise lower down at the front of the engine?

I’ve checked oil pressure and that all appears fine. Cold and hot.

I’ve now become obsessed with the noise! I cannot drive it now with the radio on.

 

[Discodevon]

Why.. I guess it’s a possibility due to it being temperature related. However I’m pretty sure if the manifold was warped it would make a high pitch squeal on acceleration ?

It also appears to make the noise lower down at the front of the engine?

I’ve checked oil pressure and that all appears fine. Cold and hot.

I’ve now become obsessed with the noise! I cannot drive it now with the radio on.

I’m not sure but my old d2 td5 did that and then eventually after a squeal appeared so did the manifold and it ran lovely after that, it may be worth checking the cam chain tensioner which is bolted on the left side of the engine, pretty sure you could swap it over?

 

[Mario110]

Too bad to hear an injector swap didn't help, you are the third person i know changing the injectors without luck. I've made some measurements on my engine just because of out of curiosity. First, i've done a vibration measurement with the app i told before. When engine is at operating temperature it's less vibrating although its louder. From vibration it's not possible to detect a bad cylinder.

Something more solid is the measurement made with my Oscilloscope. When engine is at a certain temperature level, ECU adds and eighth voltage peak. Below "this" level (i suposse it has something to do with temperature) i've only seven peaks and no knocking. Here is a video where I cut out the eighth peak by pressing the gas pedal gently:



Another video showing the voltage curve at different revs:



All injector channals are looking same, this means also that all injectors become this eighth peak. What did this tell us?

 

[uk_vette]

Get the exhaust manifold skimmed

What does that do ?
Sorry if a stupid Q.

 

[Discodevon]

Hi it can cause a knock and a screeching noise

 

[Mario110]

I've measured yesterday the current flow of the injectors. Basically they are all looking like that:

I've used a shunt with 0,11Ohm, so we have roughly 3,5A at the first peak. I'm not sure if the curve is OK, in comparision with other Unit injectors in the world wide web it looks different...does anybody know?

@Deftd506
Any news on your side?

 

[Deftd506]

I haven’t done anymore with mine, it’s just been parked up!

Have you tried another good known ecu ?

 

[Mario110]

No - didn't have one. It's worth a try i think - maybe these are symphtons of a dying ECU...

 

[Deftd506]

Or just a fuel map issue. Worth a go.

Have you had yours remapped ?

 

[Mario110]

No, everything is original. I don't think it has to do with the fuel map, because it has worked before and values from flash memory are reliable. Maybe the capacitors are getting weak, but on the other side we have error codes for "short peak injector xxx" and i think the ECU is monitoring the current usage. Otherwise this error code makes no sense.

Who knows...another ECU is still worth a try....

 

[Interceptorxj]

Have either of you considered engine mountings? When cold they could be more solid then get more plyable as they warm up. I recently change my engine and transmissiom mounts in my D2 as a precautionary measure after reading several posts about failed mountings causing uneccessary vibrations and it has certainle made a difference to the engine vibration. It is actually harsher with the new mounts than the old softer ones and i did use genuine LR. Try jacking the engine up very slightly just taking up the weight of the engine slightly with a block of wood or rubber on a trolley jack and see if this alters your engine tone in any way?

 

[Si Click]

It also appears to make the noise lower down at the front of the engine?

Have you checked your crankshaft pulley? If the damper breaks down the two parts move in relation to each other and create just the knocking you describe.

 

[Mario110]

Didn't have it checked on my engine. I would assume it should make everytime the same noise, even when it's cold. I cannot hear the knocking when engine is revving down and no injection is made....

 

[Si Click]

My comment was aimed at Deftd506, but I guess could be relevant to your issue. A faulty crankshaft pulley can often only be heard at idle as it is masked at higher revs.
Try removing the serpentine belt and seeing if you can move the elements of the crank pulley by hand. It should be pretty solid. If it is the pulley you might also find that the noise is gone or reduced with the belt removed.

 

[Deftd506]

Replaced due to squeak on shut down.. didn’t cure the knock.

 

[Si Click]

Replaced due to squeak on shut down.. didn’t cure the knock.

Yup, they make that noise too.
Could the knock be big end (crankshaft) bearings? In the early stages this tends to be heard only when the engine is hot as the oil gets thinner.