Well I'm still hearing the knocking noise intermittently. Same times and as often as before. I just heard it again today pulling in my driveway. By the time I got up my driveway and put in park, I couldn't hear it anymore. I don't think its really getting any worse, maybe just a little more frequent. But I still only hear it after having driven the truck. I just haven't gotten a chance to work on it yet.

I also noticed that it sounds like hell, on the first start of the day when its colder than the low teens. Its a real loud knocking/banging/clacking noise, I'm really not sure what it is. It definitely sounds like metal on metal or something similar. I got a video of it for you guys to listen to. I'm really not sure what it is.

I got a few more videos for you guys to watch and listen to. Not sure if they will help at all but I hope they do. After watching the third one back and comparing to Rich's videos I am pretty sure that it is an injector going out.

Is there any way for me to diagnose this further? I'm assuming a scanner would help. Hopefully I can use my Uncles, but am not sure how much info I can get from it. As in not sure if it does as much as the AE.


Here's the videos. Again as usual I'm not sure how good the sound is, so it might be easier to hear things if you have headphones. The first one is just some light driving around, in the stock tune, which seems to be quieter than the TS 75hp tune. I left the windows up, but wanted to get one with the windows down, but my phone died, lol. I am thinking that I am hearing something between about 1200 and 2000RPM, sort of like the knocking noise I hear. But I am not sure if I am hearing something, or if it is just the normal sound of the truck. What do you guys think?


This one is the cold start I was talking about, where it makes that loud knocking noise. The truck was plugged in and was about -2*. Please ignore my noisy power steering pump. Sounds like hell if you ask me, on the first start of the day, but then the noise goes away once it warms up. Do you guys think this is a good start for the temperature and being plugged in? What about the smoke output, normal? And what the hell is making that loud knocking noise? I really don't know what it is. I'm not sure if its that worn out injector, or just because the truck has higher miles, or maybe something else???


The last one is probably the best video of the knocking noise so far, after getting home school. This is what made me think it was a worn out injector, after comparing it to Rich's video. This was idling in the 75hp tune. Went to change it to the stock tune at the end, but then my buddy called me and the video ended. Haha oh well. Less than a minute or so after the video ended, the knocking stopped and I never heard it again.

 

That noise hitting my ears is like a cheese grater for a back scratcher... that be a stick. Before you go grabbing the Buck$Zooka, load your Quarter Caliber first: Round up some O-rings and an inch/pound torque wrench.

Isolate which injector is the noisy one before you touch any of them, then start in with your torque wrench set to 50 inch/pounds. If any injector bolts tighten, the injector(s) with a loose bolt should really come out and have O-rings/washer replaced.

For what it's worth, it's a good idea to replace all your injector O-rings, since you have the VCs up... and check all bolts, the UVCHs, Glow Plugs, etc.... I suggest checking the torque first, so you can know if you have torque as one of your issues.

Injector bolts have 8mm heads and injector 5 is angled toward the heat exchanger... so you will want a socket u-joint and maybe a short extension for that one. I have several lengths of extension, and they all get a workout to permit the torque wrench to clear stuff under the hood.

I have solved many injector knocks with O-rings and a torque wrench. One day I'll take a picture of the O-ring bucket and post it.

 

In that 2nd video of the cold start, you stayed in the truck a little too long to tell for sure, but it's not normal, even at -2 degrees that looks, sounds like new injector time to me.

 

Yeah its a pretty loud noise, forgot to warn you. The camera kind of amplifies it a little, its not quite as loud as the video makes it seem, but no doubt it is loud and very very noticeable.

Thanks for the info Rich, that all sounds like a plan. So are you saying that it is a for sure a loose injector, or is it a worn out injector? Or can you not really tell for sure until I get under the VC's and see if any are loose?

Either way I think I will go ahead and replace all the injector O-rings and washers and see if that helps any. I really would like to avoid having to unload the Buck$Zooka, lol. I definitely plan on fully checking everything out when I get to working on it. Is there anything else you recommend I check out or even replace while I'm under there?


Thanks Jason. Ok, sorry didn't realize that. If I get a chance, I might try and make another video. I didn't think it was normal either. And was also thinking, by sound and when I hear the knock, that it was a worn out injector or two. But I'm not for sure. I'll definitely have to try and get ahold of a scanner.

So how soon do you guys recommend that I get to working on it? I would like to do it as soon as possible, but its just hard for me to find time to work on it. I have spring break about a month away, I really really don't want to wait that long, but it would be a great time for me to work on it, and give me plenty of time to do so. It would also give me plenty of time to figure out for sure what my problem is and then get all the parts I need and want to fix it. What do you guys think? I don't want to cause more issues and make my problem worse.

A thought just came to my head as I was typing. With that torque pro app, is that anything similar to the AE, or is more of just a gauge? And if so can I get it on my phone, or do I need a computer? I was just thinking that if I could use it and it can get some data, than I could have some info for you guys to look at, and hopefully figure out for sure if it is an injector, and then which one.

 

I'm saying the O-ring approach is almost free, and it's a good idea to check everything in there anyway. O-rings and a torque wrench have eliminated injector knock on Stinky, but that's no guarantee this will work on your truck.

You're wondering if it's time to buy one or more injectors, and I'm saying "not before you try a few things".

Oh... from what you describe, it sounds like the knock is easier to hear when the ICP is elevated - another loose or bad injector symptom.

 

Ok, that's what I was thinking. I know its not a guarantee but In think it would be a good idea to do anyways, and definitely is a hell of a lot cheaper than a new set of injectors, even just a single injector. It definitely makes a lot of sense to try some O-rings first.

So with doing the O-rings how hard is it to do? I remember you saying that it is something that takes some reading up on and doing some research on to be done correctly. So is it difficult to do, or just something that needs to be read up on and made sure it is done right, to not mess up anything or cause anymore problems.

Also would there be any harm in waiting awhile to work on it, or should I get it done as soon as possible? I would like to get it done as soon as possible, but I just don't know if it will, like I said its hard to find time. I don't want to wait too long, like I said at the longest a month.

Ok, what does that mean exactly? When the ICP is elevated. Is that basically when the injectors are working harder, like when the truck is put under load?

 

The whole wait thing depends. Your truck doesn't sound as bad as my truck got. If it does get as bad a Stinky did in the really obnoxious video, shut 'er down. I was 700 miles from home when I made that vid and I kept driving (getting 18.5 MPG). The engine survived, but the injector cup didn't... you don't want a piece of that.

Injector Control Pressure is high oil pressure that actually powers the injectors. The injector solenoid does nothing more than open an oil valve - like a water valve for a central sprinkler system. The oil pressure pushes the fuel out of the injector at some pretty intense pressures. So... when you first start a cold truck, or you're stepping on the throttle in gear, the Injector Control Pressure raises - and this is when you are more likely to hear injector knock.

 

Hey thanks for the info Rich.


Well, not sure if this is the reason or not, but since the weather has warmed a little bit, I have barely heard the "knock" at all. Just heard it definitely yesterday, for the first time in awhile from what I can remember. Still sounds pretty much the same.

The only thing I noticed. Last night I stopped at my buddies house, and we were standing outside talking next to my truck with it still running. And we all noticed that there was a definite ticking or faint knocking sound coming from the passenger side. Not sure if its done it before or not, but this is the first time I've noticed it.

What I plan to do is do a whole bunch of things over my spring break in a few weeks. Got the a big list of things I want to get done, but the main thing is to do those injectors. I think I'm just going to the O-rings and hope that fixes it.

I'm still having a MPG issue. Last tank averaged about 10, which is up from about 8 or 9, but that's probably because the first trip I took on that tank was an hours drive to the auto show on the freeway, where it still only averaged about 12.5mpg. Definitely way too low.

You guys think theres any chance the previous owner put some really big gears in there? I doubt it but who knows. Any way to tell what gears I have? I'm sure its something else though.

Rich I think I'm going to pm you, if you don't mind, with some specific questions, which some are not directly dealing with this thread. Because I trust you opinion and are guessing, or at least hoping that some are easy answers, so I don't have to start a separate thread on them.

 

If you listen, and not that closely, you notice a definite engine miss, in the 1st video and for sure the 2nd. I'd bet at 271k an injector has left the building.

My stock AD's had a miss at idle...and now with the new AC's it fires pretty evenly...mine had 198k.