2000 i30 still pinging after tons of work

[si2ki30]

I bought a mint 2000 i30 September of 2009, and shortly after I got it, I started to notice some light spark knock/detonation.

It does not happen until the car warms up, summer/winter doesn't matter, mostly happens on medum or heavy acceleration.

Crusing at 2,500-3,000rpm on the highway is fine

Always using 93 octane fuel.

Now have 87,000 miles

I've done the following things and they seem to be ruled out as causes for the spark knock:

Used NDISII software to retard timing -2 degrees from 15 to 13
Replaced plugs with NGK platinum (recommended middle temperature) 10,000 miles ago
Replaced 6 coil packs
Cleaned EGR tube
Complete cooling system flush
Used MAF cleaner spray
Changed Thermostat and Water Control Valve
Replaced Air Filter
Replaced PCV valve
Added since first post:
Ran Seafoam through gas and intake twice
Ran BG44K injector cleaner

Nothing has helped - am I missing any other possible causes?

No codes, no trouble otherwise, it's ok if I take it easy in city driving, but when you have to pass a car or do an emergency maneuver, it's really annoying!


I have noticed that when I add a can of NOS Octant Booster to 93 grade fuel, the problem completely disappears, but this is pricey at $13 for every tankful.

[loystock]

Welcome to NICO.

Looks like you've spent a fortune and the problem remains. Check the air inlet and exhaust for leaks. I suggest adding a bottle of Redline SI-1 Fuel System Cleaner (@ $8 or BG44K @ $18) in the next 2 gas refills. Make sure to use Tier 1 gas only while evaluating the car's performance. I know you have cleaned the MAF sensor but I suggest you redo it again using zero-residue Contact Cleaner. If needed, use Q-tips to remove stubborn dirt but never touch the sensing element with bare hands. Clean the connector too and then apply dielectric grease.

You may also have an internal problem (marginal) with the MAF sensor assembly (cold solder and/or cracked circuit board). Unfortunately, it's difficult to evaluate a MAF sensor's performance thru voltage readings alone. You may need to hook up an oscilloscope to get a better response. So you can try this - with the engine warm, lightly tap the MAF sensor housing (w/ plastic mallet or handle of screw driver) and listen for any change in engine response. Rev the engine @ 2500 RPM and do the same thing on the MAF sensor housing. If the engine speed changes or seem to stumble, the MAF sensor is bad.

[si2ki30]

Welcome to NICO.

Looks like you've spent a fortune and the problem remains. Check the air inlet and exhaust for leaks. I suggest adding a bottle of Redline SI-1 Fuel System Cleaner (@ $8 or BG44K @ $18) in the next 2 gas refills. Make sure to use Tier 1 gas only while evaluating the car's performance. I know you have cleaned the MAF sensor but I suggest you redo it again using zero-residue Contact Cleaner. If needed, use Q-tips to remove stubborn dirt but never touch the sensing element with bare hands. Clean the connector too and then apply dielectric grease.

You may also have an internal problem (marginal) with the MAF sensor assembly (cold solder and/or cracked circuit board). Unfortunately, it's difficult to evaluate a MAF sensor's performance thru voltage readings alone. You may need to hook up an oscilloscope to get a better response. So you can try this - with the engine warm, lightly tap the MAF sensor housing (w/ plastic mallet or handle of screw driver) and listen for any change in engine response. Rev the engine @ 2500 RPM and do the same thing on the MAF sensor housing. If the engine speed changes or seem to stumble, the MAF sensor is bad.

Tapping on the MAF at idle did not seem to do much, but at low speed it might *not* make too much of a difference.

I held the throttle open to what "sounded" like about 2000 RPM(no assistant available), and for a while I did not notice anything while tapping.

Then, suddenly the engine started to dip in RPM a little, then regain RPM after awhile.

Still holding the throttle at 2,000, I kept tapping, but it did not always seem to dip RPM at the same time I was tapping.

After awhile, I stopped tapping, and now just holding the RPM at 2K with no tapping, the RPM's kept dipping every once in a while even with absolutely no tapping.

I sat in the drivers/parked and brought it up to 2,500 and it consistently dips about 200 RPM every once in a while.

Took it out for a gentle spin around the block, and I don't notice any dip while driving, although the pinging sounded worse at an even lighter throttle.

Once I was parked, of course, I forgot to check if it was dipping in park again.

No codes

What do you think?

[loystock]

Yes, it's difficult to isolate such problem and MAF sensor 'tapping' is not a reliable predictor (hit or miss). So do as I have recommended in the earlier post.

Make sure there is no obstruction/debris in the intake duct and all the tubings are secure.In addition, clean and re-install the main engine harness ground points (2 each adjacent to intake plenum near cylinder #2). Apply dielectric grease to prevent corrosion. Check the injector resistance, 10-14 ohms and Knock Sensor resistance, @ 550K ohms. You can also do a 'basic' power balance test by disconnecting one spark plug (ignition coil) at a time and observing engine response. We will only replace the MAF sensor as a last resort as it is expensive.

After applying fuel system cleaner, and with the engine warm, do several WOTs on a highway (do it safely, no need to overspeed), Do not do WOT while in Park/Neutral.

[si2ki30]

Yes, it's difficult to isolate such problem and MAF sensor 'tapping' is not a reliable predictor (hit or miss). So do as I have recommended in the earlier post.

Make sure there is no obstruction/debris in the intake duct and all the tubings are secure.In addition, clean and re-install the main engine harness ground points (2 each adjacent to intake plenum near cylinder #2). Apply dielectric grease to prevent corrosion. Check the injector resistance, 10-14 ohms and Knock Sensor resistance, @ 550K ohms. You can also do a 'basic' power balance test by disconnecting one spark plug (ignition coil) at a time and observing engine response. We will only replace the MAF sensor as a last resort as it is expensive.

After applying fuel system cleaner, and with the engine warm, do several WOTs on a highway (do it safely, no need to overspeed), Do not do WOT while in Park/Neutral.

I have not had the chance to check injector resistance or the power balance test (which I have software to do) and will get back to you about these when I get the chance.

One other behavior I noticed is as follows:

Once the engine is warmed up, and I drive around the city with light to moderate acceleration, gear 1 has none or almost no ping.

Shifts to 2,3,4 has the ping get progressively worse at the same pedal depression throughout.

What I've learned, is if I "step on it" and get past pinging RPM range, and do this a couple of times, the pinging goes away on subsequent low to moderate accelerations.

I'm suspecting the knock sensor notices an extended period of knocking and the ECM temporarily dials back it's settings.

Once I turn the car off and then on again, the pinging comes back with low to moderate acceleration, unless I "step on it" a few times.

The ECM must be erasing its temporary ping precautions on shutdown.

[si2ki30]

Yes, it's difficult to isolate such problem and MAF sensor 'tapping' is not a reliable predictor (hit or miss). So do as I have recommended in the earlier post.

Make sure there is no obstruction/debris in the intake duct and all the tubings are secure.In addition, clean and re-install the main engine harness ground points (2 each adjacent to intake plenum near cylinder #2). Apply dielectric grease to prevent corrosion. Check the injector resistance, 10-14 ohms and Knock Sensor resistance, @ 550K ohms. You can also do a 'basic' power balance test by disconnecting one spark plug (ignition coil) at a time and observing engine response. We will only replace the MAF sensor as a last resort as it is expensive.

After applying fuel system cleaner, and with the engine warm, do several WOTs on a highway (do it safely, no need to overspeed), Do not do WOT while in Park/Neutral.

Well, it looks like it was the MAF sensor all along. I found one on ebay for $54 shipped, slapped it in, clear the ecm learning, adjusted the IAVL (Idle Air Volume Learning), and instantly all of my pinging went away.

If I had only done all of my "let's replace everything" strategy in reverse, I would have had this problem figured out 9 months ago! LOL

So for anyone else that has an engine that is pinging on 93 octane fuel, but otherwise runs well/smooth and has no codes and you always maintain it properly, I would suggest replacing the MAF with a cheap new ebay model instead of the $150 parts-store version, and your problem could go away very quickly!

[ivantechpower]

I'm having the same problem,did almost the same as you, waiting on the MAF from e-bay. Can you explain were to get the software and how to clear ecm and adjust the IAVL?

[si2ki30]

I'm having the same problem,did almost the same as you, waiting on the MAF from e-bay. Can you explain were to get the software and how to clear ecm and adjust the IAVL?

I believe that if you leave the battery disconnected overnight, this will clear the ECM learning, someone correct me if I'm wrong.

Otherwise, you can get NDIS II software & USB/OBDII cable from blazt.biz and it's a little pricey, but it also lets you read and clear codes, display performance data and gauges. I am not affiliated with them.

EDIT:>> I noticed you have a 97 i30, I am not sure if the NDIS II software will work for you, or if you need the first version (which may not have ECM clearing and IAVL learning)

As for having the ECM relearn the IAVL, that may not be necessary if you've never removed the throttle body, again please correct me if I'm wrong. (I don't believe replacing the MAF would necessitate this)

If you want to have the ECM learn the IAVL, there is a method in the Factory Service Manual that doesn't require a scantool.

Well, on to my continued experience.

After a couple of days, the car was not pinging at all from replacing the MAF sensor. Now, after about 150 miles, there was just the slightest, tiniest amount of pinging, mostly heard while accelerating hard, as soon as the car shifted each gear (auto transmission).

I've grown very sensitive to this sound, and it is probably nothing, but I did some more investigating.

I decided to check the condition of the plugs, and found that they

a) had red crud deposits on them. This is due to MMT fouling from all the NOS Octane Booster I've used over the last 12 months.
b) the center electrodes had some spiky deposits

After driving with pinging for a year, using NOS Octane Booster with a very high level of MMT fouled the plugs and creating hotspots for pinging. (this particular booster can raise Octane 60 points but can foul the plugs and injectors, so when you stop using it, the pinging actually gets worse than before!).

I cleaned the red deposits off the plugs, and the little carbon spikes off the center electrode with a small brush, reinstalled, and that microscopic amount of ping went away. I'm going to change the plugs just to be safe next weekend.

Why did a little bit of pinging come back after no ping for 150 miles after changing the MAF sensor?

I would guess that after the ECM was cleared, and did its learning thing over 150 miles, it gets to the point where it adjusts all of its ratios to optimum settings. Engines run most efficiently at just before the point of pinging, and that's how engineers program the ECM, to just go up to that point. However, with the fouled plugs, it started to ping just a tiny bit - most people would not even notice it.

So I recommend you change your plugs too after you get your MAF, cheap peace of mind. Make sure you use NGK platinum -

[loystock]

I'm glad the MAF replacement fixed the problem. I'm leaning towards MAF replacement based on the symptoms but I'd rather do the basic (and free stuff) before replacing component, especially in your case where you have already replaced so many parts. I hope the MAF sensor you got from eBay last for a while. There are refurbished MAF sensors that sell for less than $100.

[JOzz]

Hate to dig up an old thread but I have been experiencing this same light acceleration pinging. I haven't replaced anything yet so I started with the NOS Octane booster and a full tank of Shell 93 octane fuel. After leaving the gas station I did 3 WOT in 2nd gear And then drove normal. This completely resolved the issue for now. So my ? is should I start with the MAF sensor and work backwards. It could probably use plugs as they havent been replaced since 100K. It has 140K now. Any thoughts or recommendations would be greatly appreciated.

[si2ki30]

Ive found that the octane booster is a temporary fix and winds up fouling the plugs with prolonged use. The mmt chemical leaves ornage deposits on the plugs. I suggest you do what i did last. Change the plugs to one step colder. This is a 6 instead of 5. And use a bottle of redline s1 fuel cleaner, just pour the whole bottle in. After a couple of tanks, let me know what happens. It worked for me finally.

Hate to dig up an old thread but I have been experiencing this same light acceleration pinging. I haven't replaced anything yet so I started with the NOS Octane booster and a full tank of Shell 93 octane fuel. After leaving the gas station I did 3 WOT in 2nd gear And then drove normal. This completely resolved the issue for now. So my ? is should I start with the MAF sensor and work backwards. It could probably use plugs as they havent been replaced since 100K. It has 140K now. Any thoughts or recommendations would be greatly appreciated.

[JOzz]

Ive found that the octane booster is a temporary fix and winds up fouling the plugs with prolonged use. The mmt chemical leaves ornage deposits on the plugs. I suggest you do what i did last. Change the plugs to one step colder. This is a 6 instead of 5. And use a bottle of redline s1 fuel cleaner, just pour the whole bottle in. After a couple of tanks, let me know what happens. It worked for me finally.

I am going to look in the how to's, but just out of curiosity, how were the plugs to change. Were they a bear or not too bad?Thanks

[loystock]

Front plugs are straightforward, the rear may be a bit of a challenge. The "how to' in this forum can help you.