CarSPIN Forums

Auto Talk => The Garage => Topic started by: Morris Minor on November 27, 2023, 03:23:25 PM

Title: G37 - pinging - pre-ignition
Post by: Morris Minor on November 27, 2023, 03:23:25 PM
Coming up to 100,000 miles and the engine is knocking under mid-intensity acceleration. I hear it around 2,500-3,500 RPM - sort of random & rattly. I'm guessing it's carbon deposits. But who knows. Bollocks. I'll call the excellent mechanic who looks after it for me. 
Title: Re: G37 - pinging - pre-ignition
Post by: Eye of the Tiger on November 27, 2023, 03:43:07 PM
Can be difficult to diag these things.
Load the parts cannon with new spark plugs, premium gas, and fuel system/intake cleaners.
Title: Re: G37 - pinging - pre-ignition
Post by: Eye of the Tiger on November 27, 2023, 03:49:39 PM
Question: does it burn oil?
Title: Re: G37 - pinging - pre-ignition
Post by: Morris Minor on November 27, 2023, 05:57:17 PM
Quote from: Eye of the Tiger on November 27, 2023, 03:49:39 PMQuestion: does it burn oil?
Barely any. Maybe a few ounces once between changes. 
Title: Re: G37 - pinging - pre-ignition
Post by: Laconian on November 27, 2023, 06:15:38 PM
Is the check engine light turning on at all? I'm kind of surprised there is any knocking. I thought that all recent-ish cars used knock sensors.
Title: Re: G37 - pinging - pre-ignition
Post by: Morris Minor on November 28, 2023, 05:16:57 AM
Quote from: Laconian on November 27, 2023, 06:15:38 PMIs the check engine light turning on at all? I'm kind of surprised there is any knocking. I thought that all recent-ish cars used knock sensors.
No check engine light. Maybe there is something actually rattling. I'm not going to spend serious money on a 13 year-old car.
Title: Re: G37 - pinging - pre-ignition
Post by: FoMoJo on November 28, 2023, 06:38:14 AM
Might be worth a diagnosis by your guy.  He can likely check the interior of the combustion chambers with a flexible tiny camera.
Title: Re: G37 - pinging - pre-ignition
Post by: GoCougs on November 28, 2023, 09:08:01 AM
Quote from: Laconian on November 27, 2023, 06:15:38 PMIs the check engine light turning on at all? I'm kind of surprised there is any knocking. I thought that all recent-ish cars used knock sensors.

Knock has to happen before it can be mitigated. If the knocking starts and then tapers off, it probably is predetonation. If the knocking starts but does not taper off, it could be external (heat shield, cats, etc.).

Could it be the gas? Lots of power, 11:1 compression ratio, 7,600 RPM and port FI (no DI) = VQ37VHR is very sensitive to octane I found. Even the manual says anything less than 91 octane is for emergencies only.
Title: Re: G37 - pinging - pre-ignition
Post by: Submariner2 on November 28, 2023, 09:00:29 PM
Quote from: Morris Minor on November 27, 2023, 03:23:25 PMComing up to 100,000 miles and the engine is knocking under mid-intensity acceleration. I hear it around 2,500-3,500 RPM - sort of random & rattly. I'm guessing it's carbon deposits. But who knows. Bollocks. I'll call the excellent mechanic who looks after it for me.

A friend of mine swears by SeaFoam, in particular the kind you inject directly into the intake while the motor is running (just be sure to do so down stream of the Mass AirFlow Sensor!) to clear carbon deposits.  Might be worth looking into.
Title: Re: G37 - pinging - pre-ignition
Post by: Laconian on November 28, 2023, 09:04:56 PM
Quote from: Submariner2 on November 28, 2023, 09:00:29 PMA friend of mine swears by SeaFoam, in particular the kind you inject directly into the intake while the motor is running (just be sure to do so down stream of the Mass AirFlow Sensor!) to clear carbon deposits.  Might be worth looking into.

The warning label on that shit is amazing.
Title: Re: G37 - pinging - pre-ignition
Post by: Submariner2 on November 28, 2023, 09:07:26 PM
Quote from: Laconian on November 28, 2023, 09:04:56 PMThe warning label on that shit is amazing.

DON'T LET THE STRAW BECOME INGESTED INTO THE INTAKE!!!!
Title: Re: G37 - pinging - pre-ignition
Post by: r0tor on November 29, 2023, 06:12:07 AM
I'd start with new spark plugs if they haven't been done
Title: Re: G37 - pinging - pre-ignition
Post by: Laconian on November 29, 2023, 11:45:15 AM
Quote from: Submariner2 on November 28, 2023, 09:07:26 PMDON'T LET THE STRAW BECOME INGESTED INTO THE INTAKE!!!!

This Will Give You Cancer. Contains: Cancer
Title: Re: G37 - pinging - pre-ignition
Post by: Rich on November 29, 2023, 01:20:32 PM
Why didn't they just name it cancer? 

The name Sounds like some sunblock lotion. Just rub it all over
Title: Re: G37 - pinging - pre-ignition
Post by: CaminoRacer on November 29, 2023, 01:35:14 PM
I should probably SeaFoam the El Camino. I put some water mist down the carb a few years ago but I don't think that was enough to clean the valves. Still getting hot spots.
Title: Re: G37 - pinging - pre-ignition
Post by: Eye of the Tiger on November 29, 2023, 03:51:20 PM
Quote from: Laconian on November 29, 2023, 11:45:15 AMThis Will Give You Cancer. Contains: Cancer

kek
Title: Re: G37 - pinging - pre-ignition
Post by: Eye of the Tiger on November 29, 2023, 03:53:06 PM
Quote from: CaminoRacer on November 29, 2023, 01:35:14 PMI should probably SeaFoam the El Camino. I put some water mist down the carb a few years ago but I don't think that was enough to clean the valves. Still getting hot spots.

Naw. Berryman B12 >>>>> Seacucumberfoam
Title: Re: G37 - pinging - pre-ignition
Post by: CaminoRacer on November 29, 2023, 04:47:29 PM
Quote from: Eye of the Tiger on November 29, 2023, 03:53:06 PMNaw. Berryman B12 >>>>> Seacucumberfoam

I didn't realize engines need B vitamins. Should I also find some vitamin C so it doesn't get scurvy?
Title: Re: G37 - pinging - pre-ignition
Post by: FoMoJo on November 29, 2023, 04:53:52 PM
Quote from: CaminoRacer on November 29, 2023, 01:35:14 PMI should probably SeaFoam the El Camino. I put some water mist down the carb a few years ago but I don't think that was enough to clean the valves. Still getting hot spots.
"Italian Tune-up" works all the time.
Title: Re: G37 - pinging - pre-ignition
Post by: Eye of the Tiger on November 30, 2023, 01:07:33 PM
Quote from: CaminoRacer on November 29, 2023, 04:47:29 PMI didn't realize engines need B vitamins. Should I also find some vitamin C so it doesn't get scurvy?

yea, or just eat better gasoline
Title: Re: G37 - pinging - pre-ignition
Post by: CaminoRacer on November 30, 2023, 02:56:35 PM
Quote from: Eye of the Tiger on November 30, 2023, 01:07:33 PMyea, or just eat better gasoline

I put 100 octane in it once. $10/gallon. The pump meter rose so fast...
Title: Re: G37 - pinging - pre-ignition
Post by: Eye of the Tiger on November 30, 2023, 04:22:58 PM
Quote from: CaminoRacer on November 30, 2023, 02:56:35 PMI put 100 octane in it once. $10/gallon. The pump meter rose so fast...

The meter always rises fast, tho
Title: Re: G37 - pinging - pre-ignition
Post by: CaminoRacer on November 30, 2023, 04:27:04 PM
Quote from: Eye of the Tiger on November 30, 2023, 04:22:58 PMThe meter always rises fast, tho

I stopped at 5 gallons because I couldn't stomach a full 12-15 gallons ($120-150)
Title: Re: G37 - pinging - pre-ignition
Post by: FoMoJo on November 30, 2023, 05:11:13 PM
Quote from: CaminoRacer on November 30, 2023, 02:56:35 PMI put 100 octane in it once. $10/gallon. The pump meter rose so fast...
Did it run any better?
Title: Re: G37 - pinging - pre-ignition
Post by: CaminoRacer on November 30, 2023, 06:20:05 PM
Quote from: FoMoJo on November 30, 2023, 05:11:13 PMDid it run any better?

Yep. 91 is the max at regular pumps here but it really likes 93 better and if 95 was available it would be even better/safer. I mixed the 100 with 91 so it was around 95.

10.5-11 compression with a carb needs a bit more octane than a modern engine
Title: Re: G37 - pinging - pre-ignition
Post by: giant_mtb on November 30, 2023, 08:56:44 PM
Rod knock.
Title: Re: G37 - pinging - pre-ignition
Post by: Morris Minor on December 01, 2023, 03:32:09 PM
Quote from: CaminoRacer on November 29, 2023, 04:47:29 PMI didn't realize engines need B vitamins. Should I also find some vitamin C so it doesn't get scurvy?
Best practice is to remove spark plugs and squeeze the juice of ½ lime into each cylinder. Do this every 10,000 miles.
Title: Re: G37 - pinging - pre-ignition
Post by: Eye of the Tiger on December 01, 2023, 06:03:42 PM
:lol:
Title: Re: G37 - pinging - pre-ignition
Post by: Submariner2 on December 04, 2023, 03:29:27 PM
Quote from: Laconian on November 29, 2023, 11:45:15 AMThis Will Give You Cancer. Contains: Cancer

PROPOSITION 65 WARNING:  This cancer is known to the state of California to cause cancer.
Title: Re: G37 - pinging - pre-ignition
Post by: Eye of the Tiger on December 04, 2023, 03:53:45 PM
Quote from: Submariner2 on December 04, 2023, 03:29:27 PMPROPOSITION 65 WARNING:  This cancer is known to the state of California to cause cancer.

PROPOSITION 66 WARNING: This California is known to the state of California to cause California.