"New" injectors leaking. Old ones are not.

[cakeordeath?]

I bought a set of newly rebuilt injectors from a highly reputable dealer well known in this and other diesel forums.

I have the early "red" 6.2 engine and the older injectors never leaked fuel. I received the correct injectors from this vendor by mail and they screwed right in.

Almost all of them started leaking immediately, even though the fuel lines were torqued to 25, then 30+ lbs. Made no difference. Closer examination showed they weren't leaking at the fuel line connection or the return tubes -- all these were dry. All the injectors were leaking from the middle part of the injector -- where it comes apart to replace nozzles.

Not only that, the engine ran rough, lots of white smoke, and it looked as if one cyclinder wasn't even firing even after 10 minutes. I didn't even drive the truck -- fire danger.

I contacted the vendor and he suggested I return the injectors so he could check them out.

I had the old injectors in a pail of solvent to clean up a bit before shipping to get my core charge back. I took them out, cleaned them off with brake cleaner and reinstalled them -- NO LEAKS! Not only that, a lot less smoke that went away in 5 minutes and idles smooth.

The vendor checked out the new ones I returned and he says they found nothing wrong with them and is sending some others back to me.

I talked to a local diesel mechanic -- the guy who installed my engine - and he says sometimes a POP test isn't foolproof. Some leaks won't make itself evident until after repeated firings. He suggests that the best thing to do might be to rebuild the injectors I have.

I won't name the vendor I bought the injectors from because so far he doing what he can to fix the problem, however I dread getting those injectors back because I've a hunch they'll just leak again.

Anybody have a clue to what's up here? I've never read about this kind of problem on any board and I did a bit of searching too.

[arveetek]

I had a similar problem with Accurate Diesel injectors I purchased. Only one of them leaked, but it was just like you are experiencing. It was supposed to be a quality rebuilt injector, but it leaked at the joint where the two halves of the injector come together. Tim sent me another injector and all is well, but I have since found out that Tim doesn't even rebuild the injectors himself, he buys them from a third party. Considering the low price Tim sells them at, and factoring in his profit, you know that these injectors can't be a quality product at all.

If I were to buy new injectors again, I would go with a local Stanadyne shop or purchase new ones from Kennedy Diesel.

Casey

[cakeordeath?]

Thanks for your comments. I'm inclined to agree with you.

At any rate, the rebuilt injectors are back here after being looked over by the rebuild shop people and I will install them in the next few days and report back.

If these still leak, I will just get new ones.

[cakeordeath?]

Well, I did get the rebuilt injectors back and re-installed them on just one bank of the engine. Results: No change. Smoke and leaking injectors.

I have dual exhaust and on the side with the new injectors, white smoke still bellows out 15 minutes after start up, even though the other tail pipe with the old injectors cleared up in 5 minutes after starting. Then 3 of the 4 installed injectors started leaking again where the halves come together.

I won't bother with telling you how frustrating all this has been, since all of us have experienced some kind difficult mechanical problem or another.

My frustrations stems from the fact that I bought these injectors from Kennedy Diesel specifically to avoid these kind of problems. I did a heck of research here and elsewhere and bought the books (from here). I followed everyone's recommendation that it was wise to buy from reputable vendors and not try to save a few bucks.

So far John Kennedy has been very accommodating. After they started leaking again tonight after I installed them, I sent an email asking that he take them back.

So my question is this: What am I doing wrong? John Kennedy doesn't know why they leak, the rebuild shop doesn't know why they leak. I've a very common engine in a very common set up. Other than the dual exhaust, it has no mods. Are brand new top dollar injectors going to solve my woes?

:confused::confused::confused:

[Kennedy]

I'm at a loss here. My only thought was to reman your existing cores, but instinct tells me to step away from this one. I guess all we can do is punt and refund your money at this point, or try to get you a brand new set. The injectors in question spray fine here (checked twice now) and don't leak when tested. Some times you will get one like Casey pointed out that leak at the body halves due to issues with lapping the bodies, but I haven't seen this from my guys in a long time and once again these were tested twice. I wasn't there when they were tested the second time, but Curt took it very seriously as it questioned their Quality Control. Not one leaked. The only thing that I can think of is that there is something with the lines.

P.S. I've done injectors myself and have had a weeper here and there, but I have never seen a weeper affect how the engine ran. I've also never seen a healthy 6.2 take 5 minutes to stop smoking.

[More Power]

Late last year while visiting US Diesel Parts (www.usdieselparts.com (http://www.usdieselparts.com)) here in Montana, I spotted a sectioned 6.5 cylinder head on one of their work benches. Curious, I asked what they were doing with a sectioned head...

I was told that, for some reason, some remanufactured 6.2/6.5 injectors leaked at the body joint. After getting some returned for leaks, they sectioned a head - leaving just one end, so they could pressure test each reman injector while it was installed and torqued into the head. I seems that torquing them into the head puts different stresses on the injector body, and some of them leak. This final QC test allows them to catch a leaker before a customer gets it.

Jim

[Kennedy]

FWIW, Bosch has Obsoleted both new and reman coarse thread injectors. I'll pass along MP's notes as well.

[cakeordeath?]

I started up my truck this afternoon after it sat for about 18 hours. It was about 60 degrees outside.

The first photo shows the smoke on the driver's side exhaust at startup, the second at 5 minutes of idle, the third after approximate 10 minutes of idle and the last after approximately 15 minutes of idle.

The passenger side exhaust (the bank with the old injectors) hardly any smoke at all.

I also noticed that the injectors started dripping fuel around the 7 minute mark.

[JeepSJ]

Late last year while visiting US Diesel Parts (www.usdieselparts.com (http://www.usdieselparts.com)) here in Montana, I spotted a sectioned 6.5 cylinder head on one of their work benches. Curious, I asked what they were doing with a sectioned head...

I was told that, for some reason, some remanufactured 6.2/6.5 injectors leaked at the body joint. After getting some returned for leaks, they sectioned a head - leaving just one end, so they could pressure test each reman injector while it was installed and torqued into the head. I seems that torquing them into the head puts different stresses on the injector body, and some of them leak. This final QC test allows them to catch a leaker before a customer gets it.

Jim

This has me wondering - would it be a good idea to lap the sections of the body as part of the rebuild?

[JohnC]

Does it run OK after it warms up? I wonder if the injection pump is having problems poping the new injectors?

[cakeordeath?]

Does it run OK after it warms up? I wonder if the injection pump is having problems poping the new injectors?

Actually it doesn't. But then I haven't actually driven the truck because too much fuel is leaking to take it for a spin. But it idles rough -- not too bad, but noticably so.

[Kennedy]

This has me wondering - would it be a good idea to lap the sections of the body as part of the rebuild?


Every proper rebuild does this. Bosch also recommends further lapping these on "blue paper" as was done with the injectors in question. I haven't done any of these in a few years, but I had a simple hand lapping block.

[simon]

I rebuild all my own injectors and for some nabors as well. I always clean all parts toroughly in diesel oil,and lap all mating parts on[don't laugh,it works] a piece of plate glass covered with crocus cloth and 40W as lubricant. I have had only one sweat leak between the 2 halves a bit. I gave it some extra torque in the vice and that sealed that one as well. I also poptest and shim all so they stay within 50 lb across all eight. A leak has not shown up on the leakdown test, so it could well affect the occasional injector deflecting when screwed in the head , but with proper cleaning of the bore and a new gasket it is highly unlikely to do so.

to have all 8 leak, i contribute that to sloppy work and NO lapping, or they are chinese junk.