Chasing the 2200 rpm ping (2.7)

That does look like a good way to go. How much are they? Not listed on thier website.

 

They're not cheap, you can definitely do a used mini-header swap cheaper, but you won't get any gains. Last I heard in the $500 range. Chris4x4 had a bunch of headers tested on the dyno and the NWOR have the best low end and overall torque gain. I found this out after I bought an LCE header. The LCE header is a nice piece, and a bit cheaper than the NWOR, but it's gains come in around 3000rpm.

 

To me, if you're gonna swap, might as well get something that will add power over stock. The headers last a lifetime too

 

Makes sense to me Sean. I already have the OEM mini header and will paint it with high temp paint and install it. Once I know I don't have a deeper engine issue, I may decide to upgrade to the NWOR header. It has the gains where I would want them. Heck, I've spend around $235 on the OEM header(header, gaskets, paint) to do it right.

 

Ok, OEM mini header installed and the exhaust leak is fixed. Unfortunately, I still get the same pinging between 2000 and 2540 rpm under load. Truck sure runs super smooth and quiet otherwise.

I also noticed that I have a rattle/tapping noise from under the valve cover at idle. It only seems to do once it's warmed up. I suspect that I never heard it before due to the cracked exhaust manifold.

I had the valves cover off to check valve lash and the tensioner seemed tight with little to no noticeable wear. I did two bad things: I rotated the motor using the cam bolt. I also rotated the motor backwards a little bit a time or two to get the lobes set right to check clearance. I know that these are both "no no's" after research. I plan to recheck torque(loosen and re torque) on the cam sprocket when I set valve lash.

Could it be that the exhaust valves are slightly under spec and causing the pinging under load and rattle/tapping at hot idle? Setting valve lash is my next step.

 

With 290k miles, you should get your valve lash checked anyway. May even need a new timing chain.

 

i checked valve lash last week. Here are some pics from under the cover.

 

Engine is super quite until it warms up. Once it warms up, the rattle/tapping noise can usually be heard at idle and the pinging is usually heard under load(or while accelerating) at 2000-2400 rpm.

Someone suggesting a spark ignition issue may be the pinging issue. But maybe I need to take a closer look at the timing chain tensioner. Is there a good way to test the chain tensioner on the vehicle?

 

I'm thinking Seafoam is my next step. Doing the shims is certainly on my list, but I have a hard time believing that exhaust valve clearance of .008"(minimum is .010") is bad enough to cause the pinging and clatter.

 

It'll always be quieter when cold. Oil is thicker

 

Change of plans. I pulled the vc and removed the exhaust cam this evening. I thought it was best to correct what I know is out of spec first. I'll be surprised if taking the valve lash to the top of the tolerance will correct the pinging or idle clatter, but it needs to be done anyway.

First step is TDC, set timing marks and install bolt(from valve cover) in cam gear.


Then loosen cam bearing bolts. Remove bolts and caps and roll cam right put of there. Easy access to all 8 exhaust shims. No regrets about going this direction. If I only had to make adjustments to 2 or 3 shims, it would be different.


Here's a few pics and a revised chart that shows how I'm keeping the shims straight. I'm plan to surface grind them at work tomorrow. I plan to get .013-.014" valve lash on all exhaust valves. The number that's circled on bag is what I plan to grind the shim to. The number on written on each shim is how much I will remove in order to get .014" clearance. I'll write the valve number on each shim after I grind it and it will go back in the bag with the valve number on it.

I've read of some trucks having knocking /rattles when cold and then none once warmed up.

 

Truck is back together and started right up and ran super smoothly with freshly set valve lash. I let it warm up to temp and no rattles/knocking. Took it for a drive and still had some pinging but it seems to be better(air is cooler tonight though). Got back home and listened carefully and engine is smooth and quiet.

At this point, ive:
1. Checked plugs
2. Tried 89 Octane Chevron
3. Cleaned the MAF
4. Replaced exhaust manifold
5. Corrected slightly out of spec valve lash

Next step is Seafoam into the intake once I research where to put it in at so it does into all intake ports.

Btw, the pinging can't be heard with radio on at unless volume is very low.

 

do you have a video of this pinging? Kinda curious what it sounds like. You're right my exhaust leak is awful but as soon as i fix that I'm pretty sure Ill have the same ping

 

I'll see if I can get a video that will capture the pinging. You have the OEM mini header dont you? What is your plan to fix your leak?

 

yes, I have a leak after the header that's really bad because it's missing a nut or 2 I believe. I'm gonna get new gaskets and nuts and see where I'm at from there, I might also have a leak after the cat. If there's a leak coming from between the header and block I'll probably just leave it until I get an lce header.

 

Gotcha. Maybe the missing nuts and new gaskets will fix it.

 

The noise you are describing is exactly what I am hearing but I have a 3.4. Now I'm wondering if it's something else not engine related.

 

Here is the video. Listen the the entire video so you can tell the difference between when it's pinging and when not. Let me know what you guys think.

https://youtu.be/KexJpn51fvc

I've also discovered that the pinging can sometimes be heard around 3K. I ran half a can of Seafoam into the intake (Evap hose that goes into the TB). I let it sit for 10 min and the took the truck for a spirited drive. Truck runs and drives great and I reved it to 5K a few times in an attempt to burn out the carbon. After driving the truck about for 20 min or so, I was thinking that the pinging may actually be better. Maybe the pinging is due to carbon build up causing pre spark ignition?????? Seems like someone suggesting that.

 

I'm not hearing it

 

Turn sound up and pay attention around 0:16-0:20 and again at 0:24-:031.