Wet diesel injector and tapping noise 300 TDi

Hi All,

Just joined as a member having bought my first ever Land Rover - a 97 Disco 300 TDi with 118k miles. Very pleased with her, however, I have an annoying fault. I have looked through many threads on here in an attempt to answer my own question. Unfortunately I have failed, so I would appreciate your help.

Firstly some history: The disco has been serviced every 6k miles from new but unfortunately the previous owner drove off without the cooling system header cap - as a result the head gasket was replaced and the valves overhauled. This was at around 70k miles. New Cooper Diesel filter fitted by me 200 miles ago (along with oil and filter).

The fault is one of those annoying tappet type noises that is much more noticeable when the engine is hot. The tapping rises and falls with revs but goes away on over-run. It is not noticeable above about 2000 rpm. There is no contamination between oil and water, it starts first time on the button and does not produce excessive smoke. I’ve adjusted the tappets 3 times, dismantled the rocker shaft (all good) and replaced the valve stem caps for good measure – all of which has made no difference.

I slackened the feed pipe off to the injectors one at a time. When the feed to No 2 cylinder was spitting diesel the noise went, and reappeared when re-tightened.

I pulled the injector out to find its tip to be soaking wet. I pulled the injector out of No 1 cylinder which was nice and dry and a bit sooty. I swopped the 2 injectors and hey-presto the tapping appeared to go to No 1 Cylinder (which I thought indicated that it was faulty).

So I bought a new injector, threw it in (torqued to 25NM) and all was quiet - for about 3 miles when the noise came back. Took No 1 and 2 injectors out to find that No 2 was wet again - so I guess that it was not a faulty injector!

Swopped the injectors (1 for 2) and all was quiet for a few more minutes until it got hot again - then the tapping came back – again inspection revealed that No 2 was wet.

So, what can be causing this? My thought process suggests that something is stopping the cylinder from firing effectively. Compression or fuel?

So, as I have not got a diesel compression tester, I thought that I would look at the fuel system. I ran the engine with the fuel line completely disconnected from No2 injector first of all, and then No1. Whilst diesel squirted out of the injector drain pipe with some force (hitting the windscreen) only a small amount of fuel was squirted out of the fuel line going to the injector union. I think that both 1 and 2 were about the same (although more fuel may have come out of No 1).

Again, when the engine is running I can get rid of the tapping noise by slackening the fuel union going to No2 injector.

So after these ramblings, do you have any ideas please?

Also, how much fuel should come out of the fuel pipe going to the injector? What are the symptoms of a knackered diesel injection pump?

Thanks in advance - this has been driving me crazy for 2 weeks now! All help gratefully received.

(One thing, I may have put the copper washer, on the new injector, in upside down - would this make a differene?)

Cheers,

GM

Hi

In answer to your last question the copper washer has an 'annulus' (raised)
portion on one side,so may not seal if up side down.

Regards
SashTony

Thanks for the info. Does the annulus side face upwards in the injector port or face down?

Hallo again

The annulus faces upwards towards the injector.
Use a screwdriver to locate the washer into the injector 'bore' & check with a torch before fitting injector.

Regards

Thanks for the advice. I've got a new copper washer and fitted it - no difference.

It now feels like it's running on 3 when I start it from cold so I've booked it into my local independant LR garage to have the head taken off to see what's happening.

Any last ideas before I shell out several hundred quid chasing a rattle?

Ginger Monkey said:

Thanks for the advice. I've got a new copper washer and fitted it - no difference.

It now feels like it's running on 3 when I start it from cold so I've booked it into my local independant LR garage to have the head taken off to see what's happening.

Any last ideas before I shell out several hundred quid chasing a rattle?

Click to expand...

Don't take the head off yet!!
First do a proper compression test.
If that is OK don't take the head off at all.

All the signs are pointing towards insufficient injection on the duff cylinder. You should have all the injectors out (Mark them so you know where to put them back) and get them checked for spring pressure settings and spray pattern. I recommend you CANCEL the LR dealer appointment until you get the injectors set up properly.

The dealers will only throw in new bits at your expense until it runs right. That could easily cost you over £1,000 if they fit a "new" pump and injectors.

Charles

Thanks for the advice,

The dealer that I have it booked in with has a diesel rig so I will ask them to do as you say first. Is it common for replacement injectors to play-up? Or do you think that it could be my pump? I've had the engine running with various injector unions taken off and only a very small amount of diesel was squirted out or each pipe.

GM

There is only a tiny amount of fuel squirted out each time.

It just has to come in the right way, and loosening pipes is NOT any sort of test except to say there is fuel coming out - full stop. But that does not prove it comes out the injector nozzle, either at all, or in the correct spray pattern.

You will need to find someone to attend to this for you.

Some of those cost a lot of money.

CharlesY

Any suggestions for a good diesel engineer in the West Midland/Worcestershire/Gloucestershire area?

GM

Any luck in sorting out the problem of noisy injection pump. I have exactly the same problem on my 97 300TDI Disco, its only done 54,000miles however the tapping noise form the injection pump turns into a bearing type of continuous rattle at around 3000rpm.

It has been standing for a while and I have recently changed the cam belt.

Thought about changing the lift pump and the injection pump but stumbled across your same issue.

Any resolution ?

Thanks

LWV8

I too have an annoying bionic panel beater in milandee.
I run it on Veggie/bio.
I have had a new set of glow plugs as 2 of them had packed up and were also wet.
Anybody got an answer????

Hi

New on landyzone. I was really impressed with the threads while trying to find why my 97 Disco TDI 300 was so flat on pullaway. Removed 12 year old catalytic converter, blanked off the EGR as it was open all the time and tweaked the Diaphragm in the Diesel pump a few degrees open and installed new injectors and what a difference - new vehicle !!

So, going so well and 60 000 Km on the timing belt, I decided to change it. Did it to the book but now I have an exagerated rattle / tinkle on idle and slight increased revs with no load and slightly when pulling. My mates landy has a very slight version of this noise but mine is very irritating. I noticed above that LightweightV8 has a noise and has also recently changed the timing belt. I did not change the tensioner pulleys, could they be making that noise or can the oil pump pressure relief valve make that noise?

Thanks for a great forum
Neil (South Africa)