leaking injector - 81 300td

Sort of an update. I thought I had traced a leak to the oil filter stand gasket, but it turns out that what the problem REALLY is (really, this time, I do believe) is a leaking injector. Only at pressure ( or speed ) and that is why I couldn't see it when the car is idling. Plus, it only seems to happen after the car is hot. I have replaced the return hose on all injectors - the leak seems to be from the return nozzle on the injector nearest the firewall - and it is still leaking.

After googling a bit, it seems that these nozzles are just pressed in, and there is precious little I can do to remedy the problem short of replacing the rascal.

QUESTION:

Assume the engine was rebuilt around 1985, but sat in a garage since 1986. I got it in May. It shouldn't have more than 10K miles on it. If I buy a new injector, do I throw anything off? I've found one on the web (parts.mbz), that is under $40 for a Bosch, which is OK, as long as I'm not hosing up something else because of a difference in the pressures in the individual injectors.

Any advice? It's not a super-bad leak at the moment, so I could wait until I see one on Ebay, if 'twere better that I do so.

TIA

Tweaks

Reply to
tweaks
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The injector nozzle's body is in two parts that screw together. There can be a small leak - oozing - at the seam and that's, I believe the cause of your engine's leak.

You can fix this. Slightly loosen the high pressure pipe to the injector. Use a large waterpump plier to tighten the injector's top half to its bottom half. Yes, the injector is torqued into the cylinder head by 50 ft lbs - that's not being disturbed, you're only tightening the top half to the bottom half. Don't expect much movement from your effort the top will probably only move a couple of mm at most.

Carefully tighten the high pressure line to the injector JUST SNUG, NO MORE. These are pipe compression fittings and over tightening them will crush the pipe and it will leak until you replace it so be cautious and rather tighten it a couple of times, until it no longer leaks. I believe the spec is only 15 ft lbs.

As to your question. Newer Bosch remanufactured nozzles have a finer spray pattern than the original nozzles. The opening pressure of a new or remanufactured nozzle is higher than old nozzles so they really shouldn't be mixed. I replaced all five, in part for that reason and in part to have a cleaner burning engine. But subsequent single replacements were made to no ill effect.

Diesel injector repair shops are often found near larger cities and such shops can rebuild and calibrate your injectors - check the local phone book.

Reply to
T.G. Lambach

Thanks! I actually get fuel on two injectors. What is happening, I believe, is that the fuel leaks, and the fabric hose then acts like a wick, drawing the fuel up and actually over to another injector! The leak ends on that second injector in the daisy chain.

Semi-strange! I will attempt to tighten it as you instructed. Appreciate all of your input. I think I'm just reaping the "benefits" of a car that sat a long time. It really is a nice car, for all of that.

Tweaks

Reply to
tweaks

Thanks! I actually get fuel on two injectors. What is happening, I believe, is that the fuel leaks, and the fabric hose then acts like a wick, drawing the fuel up and actually over to another injector! The leak ends on that second injector in the daisy chain.

Semi-strange! I will attempt to tighten it as you instructed. Appreciate all of your input. I think I'm just reaping the "benefits" of a car that sat a long time. It really is a nice car, for all of that.

Tweaks

Reply to
tweaks

Even if you develop a leak in high pressure line due to overtightening, it is easily remedied by adding aviation form a gasket to the area where the pipe contact each other... the cone section.

Reply to
Tiger

Thanks for that bit of information, as well! I always try to err on the side of caution on tightening things, especially the first time around!

Tweaks

Reply to
tweaks

Looks like a channel-lock, but there is a difference?

Is it worth me purchasing one for this job?

Reply to
tweaks

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