Hey Guys,

I'm driving an 05 G35 Coupe 6MT. If I put the car in 2nd at low RPMs (usually under 3K) and give it full throttle, I get a ticking coming from the engine bay, sounds like a ping or knock almost. Doesn't happen nearly as much after the car passes 3K, and only when it's under WOT.

I was playing around with the car two days ago and decided to do the full ECU reset, idle air volume learning, etc. The issue went away. Just yesterday I took it for a drive and it came back. I attempted to reset the ECU this time and redo the idle air volume learning (not sure if it was as good of a job as I did the first time) and it's still there.

Because the idle air volume learning (which supposedly calibrates the ignition timing) fixed the problem temporarily, I'm thinking it has to do with my timing. Because it's a click under load, it seems that my timing would be too far advanced. Is this something we can set at the ECU level or does this require a manual chain adjustment?

What do you think? I appreciate any input.

(Side note: I have changed the oil since this issue started to no avail - I have been checking oil levels and as far as I can tell I have no consumption issues outside of the very minor amount of consumption - 3k miles on this oil change and I'm just below the mark).

 

It has been doing this for the past 1000 miles or so, on various types of gas, all 91 octane. I have run octane booster, fuel injector cleaner, gas treatment, etc on different tanks to try to locate the source. The same thing happens no matter what.

I live in the Santa Barbara area and they just closed the dealer here, so the closest dealer is a 45 minute drive. In the gas it takes me to get there I might as well just figure it out. Any other suggestions?

 

ECU reset just puts the short/long term a/f ratios back to zero (or something like that). So it might be making the a/f rich until it learns the trim values.

Take it to the dealer and they can do the timing retard (as per Homie's post).

Make sure you are running the best gas you can. 91, 92 or 93 depending on where you live.

You could also have carbon buildup on the piston tops that's artifically upping the compression or creating hot spots

 

Is it something only the dealer can do? I'm assuming it just needs adjustment at the ECU level or do you think the chain is actually off?

 

Sorry for the double post, but...

I was looking around the internet and YouTube and I also have a sound similar to this:

But mine starts at probably 3.5-4k. I'm thinking my timing chain tensioner might need to be replaced or my chain is off. I'm going to look at it tomorrow and if anything needs replacement I'll be going to the dealer for some warranty work.

 

Any quality shop should be able to adjust the timing though they'll charge you for it,cost me $60 CAD to advance timing on my car 2*. I'd have the dealership do a diagnostic to make sure this is the problem.

Personally I don't think it's the chain though I could be wrong. Imo the problem would be across the entire rev range and not only under wot if the timing chain was off.

 

That's what I figured too but I was thinking if the tensioner is off or something, at WOT it could be making more sound than others. Every other belt on the car has been changed so I'm left looking at the timing chain or a completely unrelated high-pitch sound. I just want to make a connection between the two since nothing else is wrong with my car.

As far as the clicking/pinging under load...from the people that I have talked to, a timing advance is most prevalent under WOT when your timing is adjusting for the higher stress. I figured it was timing also because resetting the ECU and doing the idle air volume learning fixed it temporarily.

I'm trying to avoid trips to my dealer since it's a 45 minute drive. Paying $50 to have a shop adjust my timing sounds better to me than paying almost the same in gas to make the drive to my dealer and back.

 

I agree...if that's the problem. If it's not it could end up costing ALOT more than $50. Since the car's still under warranty I'd go for a road trip to the dealer and get a full diagnostic done,better safe than sorry.

 

Last time I went there the service manager told me it was normal. I knew it wasn't so I went looking even more and found that it's definitely not. I guess now I get to go back and explain to him that a pinging engine is not normal. We'll see what happens. I'll keep you updated on whatever I figure out.

 

Could be a chain TENSIONER (ie.. chain rattle) but I very much doubt it jumped a tooth. 1 tooth is a good 15 deg or so? It would run like crap all the time if that were the case. If it would run at all.

 

I'm not really thinking it jumped a tooth as much as I think the tensioner is off one way or another, which is why I posted the VQ40DE video. I have a sound similar to that although mine is a little quieter and requires a little higher rev (around 4K). But the pitch and fluctuation based on RPM is the same.

 

From re-reading through your posts I see you're filling up with 91. As Jeff92se suggested,try filling with higher octane and see if that fixes the problem. Though these cars need 91 that's the minimum,I fill with only Chevron 94.

 

In California I have never seen a gas station with above 91 octane. Especially where I am, 91 is the best I can get. I have used octane booster in my fuel to no avail though. Even if it was knocking, the knock sensor and self-adjusting ECU timing on this car should be able to handle it, especially from 91 octane gas.

 

I agree with everything said above, but I have had 2 G35 6MT's an '05 and an '06. Both of them pinged pretty constantly from 3-5K part throttle or WOT. The '06 has over 90K on it and still pings like a bastard. I only run 93 octane gas, but here in FL all of our gas has 10% ethanol which I think may contribute.

both of them also ping at low RPM any time you press on the gas.