2010 1.8 Altis pinging/knocking under load or acceleration

[shorty_bari]

@xenerking @Xulfiqar @Proverbial_Slang AOA

will appreciate your time on this

[askai37]

why ect is on 80s. it should be above 90c. i think t valve is missing and car is running rich

[rajaatta]

Need data list when coolant temperature is above then 85 C this data you shared is from cold start to warm up and still the fuel trims are in negative curve indicating rich fuel mixture.
It can be either rich fuel mixture or bad piston oil rings. The clear picture can be seen when you get the data out on fully warmed up engine and by driving ng few kms and then record the data both on low engine speeds and high engine speeds like 3000 plus rpms

[Xulfiqar]

And at heavy load too

[Xulfiqar]

You will need to check the MAF sensor signal voltage with an oscilloscope to determine if its any good, regular dousing with cleaners and petroleum solvents will kill the sensor or make it biased on low voltage - (Ive seen Pakistani mechanics clean it regardless if it requires cleaning or not)

The way its tested is to use something like a 10ms time base against a basic voltage, at full sudden gulp of air it should register above 3.5V spike, if its not doing that then its either lazy or gone bad which will cause the condition you are experiencing.

You can verify this with plotting the AFR sensor output - you will see a mild rich condition as compared to a high rich when suddenly accelerating the engine for biggest gulp of air.

If you lack the above tools, then find a working car with the same sensor and then swap it over and retest your car.

[shorty_bari]

Thanks brother.. I will see where to get a hold of this from and test it.
I still want to share the above OBD report with fully warmed up engine and preferbly under load.
I just want to let you know,, this pinging/knocking situation is intermittent (when it goes away magically, the performance is wayyyy better, and fuel average mileage too)

[shorty_bari]

@Xulfiqar @rajaatta

AOA guys, got chance to drive the car again for a longer journey. find below a cut from the live report:

FYI, i lightly cleaned the MAF sensor before this drive. also replaced the O ring on it.

[Xulfiqar]

I think you didnt quite deciper the post above, you need to test the MAF sensor on a scope to see it react in live time, this data is buffered and is delayed. It wont show you a bad MAF unless its really really bad (enough to cause a check lamp)

Reason is that the engine load is dynamic and changed by a lot of factors, its not a simple tabulation as you are assuming it to be.

[rajaatta]

Where are you located?

[shorty_bari]

Lahore Bedian Rd

[shorty_bari]

OK i shall get this checked the way you explained. I just brought back a report as advised earlier. fully warmed up. varying RPMS. thats all.

[shorty_bari]

AOA

yesterday i changed the MAF . swapped it from an almost new altis with the same part number. Drove the car fully warmed up for about 15 kms. No obvious difference. the knock/ ping was still there.
for my satisfaction, i put back the old MAF and drove again. and then swapped in the new one and drove again. Confirmed, no difference.

Please guide what shoud be the next step. FYI, im pretty sure this is a temperature related issue that is intermittent also.. as when it starts raining on a hot day, the pinging goes away. even on a cold night, the pinging vanishes.

@Xulfiqar @askai37

[Xulfiqar]

The ping vanishing on colder temperature is confirmation of you running lean.

[shorty_bari]

So ... What parts should I look into for testing. Just got the thermostat changed today while getting the cooling system flushed... I plan to test the ECT as soon as I get a multimeter . What else should be on the list?

[Xulfiqar]

check the AFR for response - compare with secondary O2 if you have it.

[salman108]

If you are sure that knocking happens only under load conditions,

the first thing you need to check is the health of your timing belt, and it's tensioners.

you have enough miles to warrant a timing belt change anyway, and once you do that
you may find obvious problems.

regards.

[shorty_bari]

i got the timing chain inspected last week, tensioner was changed last year.

While this was open, i got the VVTI cam gear overhauled, cleaned.

no difference.

And like I mentioned earlier, it is an ON OFF problem. it comes and goes itself. mostly knocking vanishes and performance is back in cooler weather, but not always.

[engnr.mubashir]

It’s been 2 years you haven’t got it sorted out yet.

[shorty_bari]

use punctuation please. not sure if you're reminding or asking.

if you have any insight on the issue and its solution, please state it.

[engnr.mubashir]

Bro you should understand why would anyone be reminding you. In case anyone wants then would have replied for update.

BTW I don’t have any solution but I’m also facing similar issue of pinging in my 2015 GLi 1.3 automatic. Mine pings at certain rpms and effects performance and sometime itself goes away and car runs like it never had an issue. Happens usually If I go on long drive or long rides on highway/motorway.
One more thing my car goes through is when I take u turn or running through speed breakers and try to accelerate to go quicker it doesn’t do anything like no change in RPM like normally you get response from engine like should be but nothing happens in my case also some times it doesn’t goes through this issue and responses normally like flooring the car after u turn increases rpm gives you good amount of power of being in 1 gear in normal manual car feel.

Did every possible solution nothing helps even changed fuel pump, injector checked for leaking and spray pattern, swapped MAF sensor from newer model GLi, cleaned vvt sensor nothing helped so far driving with issue since then.