300tdi Injectors - word of warning!!!

Hi All,
Recently taken the head of my 300tdi as was blowing out the rear head gasket, but that is another story. Whilst head was off decided to have a look at the injectors as always quite smoking at start and power low until warmed up etc etc. but otherwise running great.
Whilst I am pretty good (self appointed) at engines generally, diesels are always a bit of a dark art to me. I removed the injectors and after seeing a couple of tutorials took them to bits - cleaned them all up, tested spray patterns with air/oil and reassembled. Feeling pleased with myself took them down to a Diesel guy (been doing it nearly 50 years) just to make sure the new super clean injectors functioned as designed. I explained to this guy what I had done and he simply shook his head - he advised you should not take old injectors apart as they seal in one position only - sure enough all leaked to the point of being U/S.
Sulking it looked like 4x new injectors were needed. However thought I would see if I could by new nozzles. Bearmach had some at ok price (like 4 cost the same as one injector) so tried them. Installed one and took back down to Mr Diesel and he said it was actually OK. Now these are from china (didn't know when ordered) so will probably last a week but worth a go.

There is a moral here somewhere but thought this might be useful to someone

Happy Landying

Sorry to say but in this one's the moral/saying is "If it ait broke don't fix it."

MFC said:

I explained to this guy what I had done and he simply shook his head - he advised you should not take old injectors apart as they seal in one position only - sure enough all leaked to the point of being U/S.

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Of course you can strip injectors. I've been stripping and rebuilding injectors on land rovers, tractors, generators, dump trucks and water pumps for decades. My friend has the pop tester for testing them and never had an issue yet.

I did 8 300tdi injectors about 10 years ago on my Disco and Defender - stripped, cleaned, reassembled and reset the injection pressures to factory and been a dream ever since.

However, as above, if it ain't broke... Fair enough have there injection pressure and spray pattern checked - Then perhaps disassemble if things are badly out of spec.

I'm not saying you can't, just sharing my experience. If cleaning I would consider getting them tested maybe before but definitely after cleaning.

Just a quick note as got the head back on today after a longer than planned wait (machine shop was busy). Really recommend marking the head bolts both with numbers and an orientation mark so when you lost you way doing the angles, it is easy to see what has happened. One thing that was really annoying was that the injector Studs for the clamps were replaced on the bench as old ones were a bit bent and old looking- for good measure blue loctited them in. Final job today was torqueing these down to secure the injectors and would you believe it they sheared (well No1). Really ****ed of as nothing to easily get it out and the loctite ahhh. As I had bought 10 of these ERR1019 from LR Direct but branded Bearmach, decided to bench test one and it could not take the 25 Nm. Pathetic.
Sort of thing you would expect from a Blue Packet. LR Direct were good (service etc) but quality is a big question mark from Bearmach and this is not the first time. and yes torque wrench was OK.
Rant over

They must be really poor quality, I never use a torque wrench and garauntee I do stuff up to tight, dont snap nothing though.

Exactly he same experience for me with aftermarket injector studs. They are made of cheese! I was doubting my torque wrench at first and almost purchased a new one. Popped the old original ones back in and they torqued up fine.

MFC said:

Just a quick note as got the head back on today after a longer than planned wait (machine shop was busy). Really recommend marking the head bolts both with numbers and an orientation mark so when you lost you way doing the angles, it is easy to see what has happened. One thing that was really annoying was that the injector Studs for the clamps were replaced on the bench as old ones were a bit bent and old looking- for good measure blue loctited them in. Final job today was torqueing these down to secure the injectors and would you believe it they sheared (well No1). Really ****ed of as nothing to easily get it out and the loctite ahhh. As I had bought 10 of these ERR1019 from LR Direct but branded Bearmach, decided to bench test one and it could not take the 25 Nm. Pathetic.
Sort of thing you would expect from a Blue Packet. LR Direct were good (service etc) but quality is a big question mark from Bearmach and this is not the first time. and yes torque wrench was OK.
Rant over
View attachment 221778

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Looks like they are made of "Chinense-ium" a high tech spaceage material out of Asia. All the looks of hardened steal, all the strength of wet toilet paper. I can't imagine the science that went into its development.