Ginger Monkey
New Member
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. Ive 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
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. Ive 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
