Let’s talk about ping. Again.

Well I run oversized tires. The same exact tire/rim I did on my other 200k 5VZ-FE. Difference is I get faint tapping now...but at the same time this motor seems to have more power and is definitely quicker. Guess my other one was a little worn out.

 

I feel it dutiful to add in here that I have never once (that's a big deal IMHO) heard a ping come out of my 3.4 in the entire almost 18 years of its life. This is a wonderful thing to me as I had a GMC Jimmy that pinged like a bitch at every speed/load no matter what I did to try and eradicate it. But there are things that may be important as to why; I've used nothing but 91 octane and only Chevron or 76 at that-all these years. I have the stock wheels and tires. I faithfully clean my MAF sensor twice yearly.

 

If you're only hearing this under load, then I'd say you're probably experiencing ping. Another guy with a 2.7L was having this same issue recently. He tried a bunch of different things to no avail. I suggested to him that he remove his intake manifold and clean as much of the carbon build up out of it as possible. I also suggested that he either clean and flow test his injectors, or replace them with a remanufactured set. It was a decent amount of work, but his pinging was gone afterwards.

My theory is that as the miles on these trucks add up, the carbon piles up on them as well, some getting on the injector tips. This makes it difficult for the MAF and stock ecu to get the correct fuel mixture.

Page 6 is where he gets to the point of removing the intake manifold. Page 7 has some nasty carbon pics
https://www.tacomaworld.com/threads/chasing-the-2200-rpm-ping-2-7.494905/page-6

 

My motor only has 108k on it, so it’s unlikely I would think, to have that much buildup. I’ll look at a few things when I do the plugs.

 

Depending on the severity of the sound, it could be your injectors opening and closing. Go start the truck and let it get to the warm idle rpm and see if the injectors opening and closing is in sync with the taping. You can do this by placing your finger(s) on an injector. I have oversized (550cc) injectors and they make my truck sound like it has an exhaust leak lol.
If you do have ping I'm not really sure what you can do to be honest since my truck hasn't ever audibly pinged or knocked.

There is a mod you can do that involves soldering in a headphone jack to the input from the knock sensors to the ecu and plugging that with an aux cord into your stereo and going on a drive, if there's any knock or ping you'll for sure hear it that way.

 

Well I tried this, it’s hard to tell. There’s all kinds of ticking going on in there. I can definitely feel the injector firing and it does seem to line up with the ticks. BTW there ticking going on at idle and at all times. It stays consistent and syncs up with how much throttle I’m giving it..

what color are the stock 5VZ-FE injectors? Mine are an brown/orange color.....maybe the previous owner did some fuel mods?.....I’d also like to note that since I first drive this truck I noticed more pep. I got on it today to pass a semi and was really surprised and caught off guard at how much the truck got up and hauled ass. Maybe something’s been done but maybe my old one was a bit tired. I don’t know.

 

Here’s a picture of the injectors.
I tried uploading a video with sound. It’s pretty much what I’m hearing. But I can’t get it to upload....

 

I thought I replied but I guess I didn't
But those are stock, they look just like my old ones. This engine probably also has less cylinder pressure loss than the other one. I have 183k on my 3.4 and it used to have 145-150 psi per cylinder but I used some "engine restore" stuff and it boosted them all to 190-210. I'm not sure how it affects bearing surfaces, but I have like 6k on the stuff still in the motor and zero noise or issues.

 

I found a video on YouTube of a guy showing the injector tic on his Challenger. Mine sounds pretty damn similar. Just a bunch of tics. But I’m still going to take it to someone to listen to it. It will be a few weeks at leas until I get around to it.

 

By the way what was that stuff you used? Might be worth putting it in my old one to see what happens.

 

You'll probably be ok, but safety and maintenance helps these trucks last, so whatever you can do to make sure it isn't gonna explode is good

 

CSL Engine restore (copper, silver, lead? I think?)
Its full of soft metals that embed themselves in the cylinder walls and restore compression, I'd bet they have the same interaction with bearings too.

 

I really hope that was same sick joke? Haha. But really. Explode?

 

haha yes that was a joke. Also take into account the stuff behind these trucks is old, they make unnecessary noise lol

 

So I changed my spark plugs today. I’m thinking that for 108000 miles they were never replaced. It still has the Denso in one side and NKG in another. The engine definetly sounds better. I’m not sure if I’m still experiencing the sound I first heard, I’ll have to drive it a bit to find out.


Densos



NKGs

 

If you decide on the snow methanol kit here is a great link for installation in two hours,

https://www.americantrucks.com/gmc-...ater-methanol-injector-0717-manu-install.html

 

I know that I am getting tired of my ping, it comes on around 2500 rpm's and stops once I get to 3000 rpm's.
I wished I knew how to get rid of it, without sinking another $1000 into the truck.

Forgot to add that this is a 3.4L supercharged 5 speed, 4x4 with methanol injection. Problem is, my pinging starts before I start making boost and the methanol starts spraying.

 

Are you referring to the 7th injector kit?

 

Yes, I need something that will help get rid of my pinging, but that is a lot of money.

 

I gotchya. Yeah it is. I'm not planning on running the sc w/o meth and the 7th injector because I'm at sea level. Bummer we can't run an intercooler setup, but I guess I can just look for good deals as I work my way towards the complete setup.