Engine sound... Pinging?

Inneh

Member
Aug 4, 2020
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Seattle, WA
What does it sound like in these cars? My sound happens under heavy load, sometimes it can be heard just wot for freeway entrance, but I notice it more easily when maintaining speed on an uphill. Probably more noticeable due to engine roaring or not.

So, this is very specific - it sounds like a plastic bb inside a glass jar, muffled by hand or cloth, shaken very quickly. Super faint, tink ta tinktinktink ta tink. I tried recording it but it is faint enough that the wind noise and normal engine noise drowns it out. I can hear it better with the window down, but mostly only if there's trees or whatnot to reflect off of.

Is that what this is? I need to try a higher octane (was waiting to get an empty tank), but also I'm wondering about the coil pack or a vac leak. Vac leak suspicion because the idle hangs high all the time until it's at 100% op temp.

Thanks
 
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Shuttleman83

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Jun 30, 2019
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Could be exhaust leak up around headers, could be valve tick, but most likely just standard pinging from bad pump gas. Did you use regular 87 from soeme no name place? Try 91-93 octane from Sonoco once or twice, run it through, also run some ISO HEET Red Bottle through a quarter tank.
 

Inneh

Member
Aug 4, 2020
24
5
13
39
Seattle, WA
Okay so since I posted this we've narrowed some things down.

Octane doesn't matter.
Gas brand doesn't matter.
I've put multiple bottles of Techron through it since it was driven by a grandma driver for the first 195k of its life below 2500 rpm.
Plugs/wires/coils are new.
*using Bosch Plat +4 at the moment, I've heard mixed opinions. Considering switching to Motorcraft or Autolite.
Pcv was changed, but immediately vented with breather filter.
Hose on passenger side valve cover is also now removed and being vented. Very oily smell while idling parked. (What is this one?)
*The pinging noise happened before and after pcv replacement/changes, although it seems more now.
*Does the pcv system have any phantom influence on a/f ratio? Confused since unmetered.
EGR valve has been removed, cleaned, and manually tested (provided vac with mouth). Double checked operation by applying vac while idling, it stumbled and died.
*What is the other thing directly next to the EGR valve that looks like one and has similar vac line going to it? This one fluttered unreliably when I attempted to apply vac test to it, won't hold same as EGR.
Engine does burn oil. I need to pull the plugs now that it's been a couple thousand miles to read them and check gaps even tho pregapped.
IAC likely needs changing, I believe that is the culprit of the rough idle and occasional hanging rpms.
And again, no CEL. Confirmed with Torque app.
No hesitation or stumbling. If I have the radio on you'd never know it was happening, only audible. This is what is making me doubt pinging... Not sure how much it happens at WOT because it isn't loud enough, but can/does happen at almost any engine load. Louder uphill and more acceleration (highway on ramp).
I don't know how to hunt for and find exhaust leaks.
It's not valve noise.
 
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Inneh

Member
Aug 4, 2020
24
5
13
39
Seattle, WA
Fun facts:

I guess my car or engine is a CA model. The "second" egr looking thing is a smog Diverter valve air bypass something or other. Can't find much on testing or whatnot. Hopefully it's not the engine only with a non CA ecu and it's missing the codes. Any input would be cool.

Also... Mobil Super+ today seems to have stopped the pinging! Didn't hear it today. Other premiums havent been successful. Not sure if that's good or bad, I still don't know where the problem is.

Why no DTC.... I have the Torque app, are there parameters that I can check and troubleshoot that way? Is there a knock sensor and if so is there a trouble code for when that fails?
 

Inneh

Member
Aug 4, 2020
24
5
13
39
Seattle, WA
Okay so. Replaced the IAC, spent 25-40 miles letting it relearn idle. Also changed the plugs to Motorcraft AGSF22CA coppers gapped to 0.054. Old plugs, Bosch platinums, look terrible but I can't pin down what the primary symptom is from a Google search of reading plugs.

That tank of Mobil didn't help, it still made/makes the noise. Even with replacing both of these and letting it relearn, I still get the racket at mid to high rpms or heavy load. Less if it's premium.

Can someone help with these old plugs... I'm guessing carbon fouling on some but I'm unsure. Definitely have some wet threads on some but the tips are dry. Fair amount of soot that you can see began to flake off. From what I've gathered the wet threads is likely valve cover leak? Also a couple of them have a dark spot on the porcelain, is this the misfiring?
 

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wmburns

SN Certified Technician
Aug 14, 2009
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To me I see evidence of "carbon tracking" on 2, 3, and 5. I can't see the others. However the fact the problem did not go away with new plugs and wires likely says that the carbon tracking wasn't the primary cause.

What has been done to rule out excessive carbon deposits in the combustion chamber? There are some affordable borescope camera attachments for many smart phones.

What has been done to rule out clogged fuel injectors? Consider Injectorrx.com

Sounds like there's a lot of blow by in this motor. Excessive blow by will also affect combustion. The fact the noise occurs under heavy load is a clue. One possible counter measure is to decrease the spark plug gap.

What is the results of a compression test?
 

Inneh

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Aug 4, 2020
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Seattle, WA
I have put a silly number of injector cleaners through, between techron and Lucas, always in 1/3 to 1/2 tank. Single treatment of seafoam in the tank, was considering seafoaming a vac line. I did try the seafoam with a spray tube designed for pre-throttle body treatment but didn't notice anything. I've bypassed pcv with breather filters.

I have been musing a comp or leakdown test, was actually just speaking to my father about it last night. That will be my next course. Gotta figure out how to do it without a compressor. Interested in the boroscope idea.

I'll report back when I do the test, I've been suspecting oil consumption thru the seals or rings. I know the rear main is a culprit, but due to certain behaviors while running... Yea.
 

7991LXnSHO

wanna catch the space herp
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Sep 1, 2010
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That’s because you have put mostly silly, mild injector cleaners in, and one can that is not an injector cleaner at all.
B-12 Chemtool is the serious stuff you can get most any place. BG 44K is moderately serious. Sea foam in the intake with the tube is the right idea for carbon buildup. It’s a waste in the tank. (Before anyone flames me, please look up the ingredients on the Material Safety Data Sheets so we can discuss this with facts. Google the ingredients if it had been too long since you took chemistry. There are some big, esoteric terms on the MSDS.)

Unless you have a big air bubble/tank to fill offsite, I do not know how you can do cylinder leak down tests. The compression test does not require a compressor. Then repeating the test with a couple of squirts of oil in the cylinder can give an idea if it is the rings or heads that are weak seals.
 

Inneh

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Aug 4, 2020
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Seattle, WA
That’s because you have put mostly silly, mild injector cleaners in, and one can that is not an injector cleaner at all.
From all the reading I did I felt techron concentrate, Lucas, and b12 were the most potent... The only place that has b12 around here is Walmart and its a drive that I don't take much. Either way, it's had a good half a dozen or so courses in the past couple months. I'll check out injectorrx.
B-12 Chemtool is the serious stuff you can get most any place. BG 44K is moderately serious. Sea foam in the intake with the tube is the right idea for carbon buildup. It’s a waste in the tank. (Before anyone flames me, please look up the ingredients on the Material Safety Data Sheets so we can discuss this with facts. Google the ingredients if it had been too long since you took chemistry. There are some big, esoteric terms on the MSDS.)
Cool.
Unless you have a big air bubble/tank to fill offsite, I do not know how you can do cylinder leak down tests. The compression test does not require a compressor. Then repeating the test with a couple of squirts of oil in the cylinder can give an idea if it is the rings or heads that are weak seals.
Good to know about the compressor. Does the oil essentially isolate the top end from the rings?
 

7991LXnSHO

wanna catch the space herp
10 Year Member
Sep 1, 2010
5,817
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Kearney, NE
From all the reading I did I felt techron concentrate, Lucas, and b12 were the most potent... The only place that has b12 around here is Walmart and its a drive that I don't take much. Either way, it's had a good half a dozen or so courses in the past couple months. I'll check out injectorrx.

Cool.

Good to know about the compressor. Does the oil essentially isolate the top end from the rings?
The squirt of oil temporarily seals the pistons with worn rings so the compression goes up.

Techron is not bad. It just the same mild stuff you should be getting already with every tank with good gas. Read the MSDS, as most of the internet knows nothing beyond the brands. If it has 3-4 cancer causing solvents that need to be in a metal can and not on the paint, that’s the one to run on a schedule like every other oil change and when you suspect something needs cleaned.
I do not know if cleaned injectors are going to help, but if you’re loosing oil out the tailpipe, the compression test is next.
 
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Inneh

Member
Aug 4, 2020
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Seattle, WA
What is to be said about spirited driving to clear said carbon buildup in the cylinders with seemingly nasty misfiring.... I'm guessing not so much. This car doesn't get much of that, and it's early life was a grandma and a kid who drives no higher than 2500. I've tended to go easy on it until things were patched up.
 

wmburns

SN Certified Technician
Aug 14, 2009
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I have put a silly number of injector cleaners through, between techron and Lucas, always in 1/3 to 1/2 tank. Single treatment of seafoam in the tank, was considering seafoaming a vac line. I did try the seafoam with a spray tube designed for pre-throttle body treatment but didn't notice anything. I've bypassed pcv with breather filters.
If you believe that any "in tank" cleaner will always restore fuel injector performance your understanding of the issues and limitations of the "fix" are flawed.

Your dilemma is that you want to know WHY your motor is pinging. The reported symptoms would tend to indicate there maybe a lean misfire occurring under high load conditions. There are tons of "possible" causes. For the home DIY'er the typical response is to try to change parts to rule possible causes in or out.

If you had access to a pico scope you could look at the ignition wave form and likely the answer would jump off of the screen. However few of us have access to a pico scope.

I have had great success using injectorrx.com cleaning and flow test service. You get a detailed report of the injector flow and pattern before and after cleaning. I have done 4 motor swaps and always have the injectors cleaned before putting the new motor back together. This allows me to start with a "known good".

Also don't ignore the carbon build up angle and how it's possible to contribute to pinging. HOW? The carbon takes up space inside the combustion. This has the effect of raising the compression ratio. However IF carbon build up were your only problem then likely using higher octane fuel would change the pinging symptom.

I have had some marginal success pouring Seafoam directly inside the cylinders with the spark plugs removed. Allow the Seafoam to set and work in. Be sure spin the motor over several compression stokes to remove all of the Seafoam before re-installing the spark plugs. Even better. Turn the motor over by hand before re-starting. Expect to see TONS of white smoke out of the tail pipe until all of the Seafoam has been burned off.
 
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