04’ Lb7 smokes a lot at idle

[sneaky98gt]

Awesome.. This is helping me narrow down to the actual injectors I need to order. I'll have to spend some time searching for a thread/how to on replacing them to make sure I don't need any specialty tools. From what I have seen it looks like you just need to remove some of the hoses and stuff up top (similar to the 5.3 liter knock sensors) and then take off the valve covers.. but having never actually done it.. I am sure there will be some tool that is required and/or super handy that just makes life easier.

Is there a brand that is best? In my research leading up to me finding this forum I kept seeing BOSCH everywhere.. but tons of people warning of "fake" BOSCH as well.. Or is there a reputable site to order from? @Bdsankey had mentioned sending me a message with some info.. Haven't seen one come yet (to be fair.. it hasn't been that long)


Thank you for sharing your knowledge base.. I have far less anxiety now about spending $2k or so on injectors than I did yesterday. Much appreciated

It's a fairly involved job, but there's really not anything that difficult about it. I'm a decent DIY mechanic, and I didn't really have any trouble at all. Took a weekend, and that included plenty of beer drinking time.

The was only two "difficult" (more like 'tedious') parts of the job:
1. Scraping the gasket material off of the valve cover. Just very tedious.
2. Cleaning up the injector cup seats in the head (basically removing the old Loctite material so you have a good sealing surface). I used a brass tube brush attached to a drill, which worked fairly well, but was still difficult to get to and see what you're doing.

As far as special tools, the ones I can think of:
- Metric crowfoot flare wrench set (for the injector lines); they're either 17mm or 19mm, I forget. Link
- Injector puller. Some say you can use a prybar, but I found the tool to work nicely. Link
- A good set of hex keys. Both socket drive and L-shaped. Square ends for breaking loose, ball tips for getting the screws out the rest of the way.
- Decent torque wrench.

There's good arguments both ways regarding pulling and resealing the cups or not. But for me, there's no way I'd spend that much time and money, and NOT go ahead and reseal all the cups. If you do pull the cups, you'll need:
- Cup puller. Worked great, though I do think I had to find a larger washer than what came with the tool. Link
- Loctite for resealing the cups. LOTS of people have used the 272 Loctite (red, high temp thread locker) for many years without issue, but I used the 620 Loctite (green, high temp retaining compound) because it's stronger and designed specifically for this purpose. But, it's up to you and the 620 will probably cost a few bucks more. Link
- As described above, some way to clean the old Loctite off. Brass pipe brushes, etc. I also pulled my glow plugs and jerry-rigged an air line into the cylinder to keep positive pressure on it to keep debris out (though it probably doesn't matter much).
- New set of cup o-rings (ask whoever you buy the injectors from about these)

As mentioned above, there's good reason to replace the high pressure lines now also, as they're likely rusted and in not-great shape. That said, they're pretty expensive and many people clean and reuse them. Mine were terribly rusted, but I still decided to reuse them. The key is to not mechanically clean them (i.e. brushing, sanding, polishing, etc.), because that will damage the sealing surface. I stuck mine in an ultrasonic cleaner with a chemical called EvapoRust. Lemme tell you: that stuff is magical. They came out looking about 98% as good as brand new, and I've no issues with the lines thus far (~15k miles later).

 

[GO0BER]

It's a fairly involved job, but there's really not anything that difficult about it. I'm a decent DIY mechanic, and I didn't really have any trouble at all. Took a weekend, and that included plenty of beer drinking time.

The was only two "difficult" (more like 'tedious') parts of the job:
1. Scraping the gasket material off of the valve cover. Just very tedious.
2. Cleaning up the injector cup seats in the head (basically removing the old Loctite material so you have a good sealing surface). I used a brass tube brush attached to a drill, which worked fairly well, but was still difficult to get to and see what you're doing.

As far as special tools, the ones I can think of:
- Metric crowfoot flare wrench set (for the injector lines); they're either 17mm or 19mm, I forget. Link
- Injector puller. Some say you can use a prybar, but I found the tool to work nicely. Link
- A good set of hex keys. Both socket drive and L-shaped. Square ends for breaking loose, ball tips for getting the screws out the rest of the way.
- Decent torque wrench.

There's good arguments both ways regarding pulling and resealing the cups or not. But for me, there's no way I'd spend that much time and money, and NOT go ahead and reseal all the cups. If you do pull the cups, you'll need:
- Cup puller. Worked great, though I do think I had to find a larger washer than what came with the tool. Link
- Loctite for resealing the cups. LOTS of people have used the 272 Loctite (red, high temp thread locker) for many years without issue, but I used the 620 Loctite (green, high temp retaining compound) because it's stronger and designed specifically for this purpose. But, it's up to you and the 620 will probably cost a few bucks more. Link
- As described above, some way to clean the old Loctite off. Brass pipe brushes, etc. I also pulled my glow plugs and jerry-rigged an air line into the cylinder to keep positive pressure on it to keep debris out (though it probably doesn't matter much).
- New set of cup o-rings (ask whoever you buy the injectors from about these)

As mentioned above, there's good reason to replace the high pressure lines now also, as they're likely rusted and in not-great shape. That said, they're pretty expensive and many people clean and reuse them. Mine were terribly rusted, but I still decided to reuse them. The key is to not mechanically clean them (i.e. brushing, sanding, polishing, etc.), because that will damage the sealing surface. I stuck mine in an ultrasonic cleaner with a chemical called EvapoRust. Lemme tell you: that stuff is magical. They came out looking about 98% as good as brand new, and I've no issues with the lines thus far (~15k miles later).

This is a lot of awesome info. Thank you!

 

[GO0BER]

It's a fairly involved job, but there's really not anything that difficult about it. I'm a decent DIY mechanic, and I didn't really have any trouble at all. Took a weekend, and that included plenty of beer drinking time.

The was only two "difficult" (more like 'tedious') parts of the job:
1. Scraping the gasket material off of the valve cover. Just very tedious.
2. Cleaning up the injector cup seats in the head (basically removing the old Loctite material so you have a good sealing surface). I used a brass tube brush attached to a drill, which worked fairly well, but was still difficult to get to and see what you're doing.

As far as special tools, the ones I can think of:
- Metric crowfoot flare wrench set (for the injector lines); they're either 17mm or 19mm, I forget. Link
- Injector puller. Some say you can use a prybar, but I found the tool to work nicely. Link
- A good set of hex keys. Both socket drive and L-shaped. Square ends for breaking loose, ball tips for getting the screws out the rest of the way.
- Decent torque wrench.

There's good arguments both ways regarding pulling and resealing the cups or not. But for me, there's no way I'd spend that much time and money, and NOT go ahead and reseal all the cups. If you do pull the cups, you'll need:
- Cup puller. Worked great, though I do think I had to find a larger washer than what came with the tool. Link
- Loctite for resealing the cups. LOTS of people have used the 272 Loctite (red, high temp thread locker) for many years without issue, but I used the 620 Loctite (green, high temp retaining compound) because it's stronger and designed specifically for this purpose. But, it's up to you and the 620 will probably cost a few bucks more. Link
- As described above, some way to clean the old Loctite off. Brass pipe brushes, etc. I also pulled my glow plugs and jerry-rigged an air line into the cylinder to keep positive pressure on it to keep debris out (though it probably doesn't matter much).
- New set of cup o-rings (ask whoever you buy the injectors from about these)

As mentioned above, there's good reason to replace the high pressure lines now also, as they're likely rusted and in not-great shape. That said, they're pretty expensive and many people clean and reuse them. Mine were terribly rusted, but I still decided to reuse them. The key is to not mechanically clean them (i.e. brushing, sanding, polishing, etc.), because that will damage the sealing surface. I stuck mine in an ultrasonic cleaner with a chemical called EvapoRust. Lemme tell you: that stuff is magical. They came out looking about 98% as good as brand new, and I've no issues with the lines thus far (~15k miles later).

as I am now spending the time to actually read through and look the suggested tools I had a question. When it came to pulling/resealing the cups for your injectors.. did you just reuse/clean them.. or buy/install new?

That and valve cover gasket material definitely sounds the worst (cleaning any metal surface without damaging it is always a pain in the rear).

I've put the tools in my amazon cart to probably order later tonight or tomorrow. But I appreciate the heads up on them.. those are tools I didn't have (even the crows foot) and they are exactly the type of tools I figured would exist

Knowing that I will likely order the SAC00 injectors.. I found them here: https://ssdiesel.com/product/lb7-duramax-injectors-2001-04/

Is that the best place to get them? From the reading on their website it looks like they are the Mftr of them.. but wasn't sure as I also found them available on a few other websites; that said.. it looks like they all copied/pasted the same reading/information about the injectors..

 

[2004LB7]

for pulling the cups https://www.duramaxdiesels.com/forum/threads/the-20-lb7-injector-cup-tool.31371/

 

[KyleC4]

You can order injectors from any source you want to. Just make sure they are an actual authorized dealer for the product. Just in case there is an issue and something needs to be warrantied. Also pick a place that has great customer service. Which is harder to come across these days

 

[sneaky98gt]

as I am now spending the time to actually read through and look the suggested tools I had a question. When it came to pulling/resealing the cups for your injectors.. did you just reuse/clean them.. or buy/install new?

You should be able to reuse the cups. It's possible you could damage them if you're really careless when removing them, but unlikely. If I remember correctly, they're machined from a type of hard stainless steel, and they're pretty tough. Mine had some carbon around the tips (as should be expected). The ultrasonic cleaner had them looking literally brand new in a couple of minutes, but any sort of cleaner should work well. Because they're fairly hard, and that they don't really "seal" anything, you could also use something like a Scotchbrite pad if needed to help clean them up.

You definitely will need new o-rings, though.

When reinstalling, be careful to ensure that the tip is engaged in the head correctly before just haphazardly pressing them in. This should be relatively obvious, but I remember a post on here a little while back from a guy that had just mashed the cups in without properly aligning them, and consequentially destroyed the head....

Also, one other clarification: we've mentioned several times about pulling the cups as if it's entirely a choice. It's not always. Sometimes, they stay in the head, but other times, they'll come out with the injector. Just depends. While most of my cups did stay in the head, I had 2 that came out with the injector. That's one other reason why my opinion is to simply plan on pulling and resealing all the cups (i.e. get the o-rings and puller tool ahead of time, go ahead and drain the coolant, etc.)

 

[Bdsankey]

I was going to comment but @sneaky98gt pretty much nailed it. We personally don't like reusing lines if there is any signs of pitting or debris as it (to us as a shop) not worth the risk of having a denied warranty claim due to debris/contamination (and they're under $400, cheap insurance IMO). We use red loctite 272 on cups and a brass brush to clean the seating surface in the head.

 

[GO0BER]

You can order injectors from any source you want to. Just make sure they are an actual authorized dealer for the product. Just in case there is an issue and something needs to be warrantied. Also pick a place that has great customer service. Which is harder to come across these days

Touche.. Customer service is becoming less and less service and more and more customer avoidance..

 

[GO0BER]

You should be able to reuse the cups. It's possible you could damage them if you're really careless when removing them, but unlikely. If I remember correctly, they're machined from a type of hard stainless steel, and they're pretty tough. Mine had some carbon around the tips (as should be expected). The ultrasonic cleaner had them looking literally brand new in a couple of minutes, but any sort of cleaner should work well. Because they're fairly hard, and that they don't really "seal" anything, you could also use something like a Scotchbrite pad if needed to help clean them up.

You definitely will need new o-rings, though.

When reinstalling, be careful to ensure that the tip is engaged in the head correctly before just haphazardly pressing them in. This should be relatively obvious, but I remember a post on here a little while back from a guy that had just mashed the cups in without properly aligning them, and consequentially destroyed the head....

Also, one other clarification: we've mentioned several times about pulling the cups as if it's entirely a choice. It's not always. Sometimes, they stay in the head, but other times, they'll come out with the injector. Just depends. While most of my cups did stay in the head, I had 2 that came out with the injector. That's one other reason why my opinion is to simply plan on pulling and resealing all the cups (i.e. get the o-rings and puller tool ahead of time, go ahead and drain the coolant, etc.)

Oh good.. the more stuff I can re-use to keep costs down the better

I have every intention of doing anything/everything I can while in there so I can minimize the chance of having to get into it again in the near future..

Cups will definitely be pulled/cleaned/reinstalled.. This is a truck that is pretty much dedicated to long distance travel and will often times have an RV behind it.. I don't want to run into issues while on the road lol

 

[GO0BER]

I was going to comment but @sneaky98gt pretty much nailed it. We personally don't like reusing lines if there is any signs of pitting or debris as it (to us as a shop) not worth the risk of having a denied warranty claim due to debris/contamination (and they're under $400, cheap insurance IMO). We use red loctite 272 on cups and a brass brush to clean the seating surface in the head.

Saw your PM before this.. sounds like for me it may just be better to order new lines than worry about trying to clean the old ones.. I have a few vehicles in line for repair before I get started on the truck.. but hoping to get started on it in the next week or so.. I'll be in touch via PM about what to order and when.


All this info is very much appreciated.. Can't thank you all enough.