My engine is knocking/pinging on 87/89 octane

[AZ Hella]

You should be shifting at a higher rpm for sure. If you indeed are shifting 1-2 at 9-10 mph and accelerating, that's to much load for the low rpm. The pentastar does not like low rpm in fact, the engine when shifted and driven in the 2,500-3,000 rpm range will yield much better fuel economy than shifting/driving at a lower rpm.

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[AussieJLOverland]

I'm not sure about US models of JL with the 3.6 but the Australian model sold here (same but rhd) states in the manual from Jeep that ethanol content of fuel should not exceed 10% because anything higher can cause damage to engine & void warranty. The 3.6 doesn't like ethanol fuel.

 

[mwilk012]

It’s almost always the manual transmission owners that complain about this. The tune sucks.

 

[1BadManVan]

I looked it up for a 2018, Jeep Wrangler V6 3.6 and it said 10.6...THAT said changing CRs is done all the time to meet mpg and hp and EPA standards etc, nothing unusual...that why I looked it up!

They still made the JK with the old 3.6 for 2018 model year and then switched to the JL later in 2018 with the new pug motor. I assume since he’s in a JL forum, he’s got a JL, which means he’s got the higher compression motor. I’m honestly surprised they would call for 87 on an 11.3:1 motor.

I’ve heard this pinging is more prominent at lower sea level as well. We just run 91 in our 2019 and never have any knock issues. I don’t mind paying the few extra bucks at the pump. We don’t put a lot of miles on ours

 

[roaniecowpony]

I have a 2018 3.6, auto JL. I never hear it ping. I have 37" tires on it now and it still never pings. First thing to look for is trouble codes.

 

[DonBindas]

The rattling nut or washer is an apt description.
Carbon build up in the cylinders is a common source of detonation (pinging).
The most common cause of carbon build up is the ingestion of oil vapor from the crankcase.

This can be cause by a failed PCV valve or by an internal intake manifold leak.
If your engine is consuming some oil between changes these would be candidate reasons. With a 3000 mile OCI you might not notice minor oil consumption.

A simple check you can do for an internal intake leak is to disconnect the PCV valve and cork both openings. Then remove the oil fill cap, start the engine and use a small flap of paper to cover the oil fill opening. If it sucks down, you have a leak. If it flaps up and down or lifts, no leak or a very small leak - likely no problem.

The PCV valve is not particularly expensive, you might just replace it to eliminate it from the equation.

To stop the carbon induced pinging a good method is to use a combustion chamber carbon remover product, ensuring that it is safe for the catalytic converters and O2 sensors. If the pinging goes away after using the carbon remover you've at least identified the reason for it.

On a recent vehicle I did the internal leak test, it failed and I took it to the dealer for repair (a new gasket & the carbon remover). So likely could be covered by a warranty.

LF

Good Call-I didn't notice if the Jeep in question was a 3.6 or a 2.0T? If it was a 2.0-it's important to add an oil canister within the PVC system to collect the oil before it gets pulled into the combustion chamber that can cause a carbon build up.

 

[azwjowner]

You should be shifting at a higher rpm for sure. If you indeed are shifting 1-2 at 9-10 mph and accelerating, that's to much load for the low rpm. The pentastar does not like low rpm in fact, the engine when shifted and driven in the 2,500-3,000 rpm range will yield much better fuel economy than shifting/driving at a lower rpm.

Yep. Check the manual; I think it recommends you shift from 1-2 at 15 MPH.

 

[I35]

There is a recall , took my 2021 wrangler to the dealer as it was pinging even with shell premium. After some time the dealer informed there was a recall, took it in and they removed the carbon build up in the engine and changed the pcv valve to a new designed one I was told. The pinging is gone but still using shell 93 premium.

 

[jjvincent]

Check the codes. If an engine is knocking too much, it'll throw a code. That's a good start as to diagnosis. Plus, you can get a bad batch of gas. No reason at all that you can't run 87 octane gas in it. Thousands of people do it and they survive just fine. Remember, this motor is used in SUV's and Minivans. Moms taxi is not going to be using top tier gas or premium, let alone good maintenance.

 

[I35]

I was wrong, it was not a recall but a Service Bulletin

 

[BRuby]

From day one have only used plain jane 87 from Chevron with up to 10% ethanol. JL runs perfectly with no pinging or knocking at sea level and at high elevations. Driving fast or slow - under high load or not. May cost more but is worth it. Hot or cold. Zero hesitation. Zero stalling. Easy starting every time.

[when using high-quality unleaded "Regular" gasoline having an octane rating of 87 as
specified by the (R+M)/2 method. The use of higher octane

"Premium" gasoline will not provide any benefit over "Regular" gasoline in
these engines.

While operating on gasoline with an octane number of 87,
hearing a light knocking sound from the engine is not a
cause for concern. However, if the engine is heard making
a heavy knocking sound, see your dealer immediately.

Use of gasoline with an octane number lower than 87 can cause
engine failure and may void or not be covered by the New
Vehicle Limited Warranty.

Poor quality gasoline can cause problems such as hard
starting, stalling, and hesitations. If you experience these
symptoms, try another brand of gasoline before consider
ing service for the vehicle.]

Porsche requires high test 93 - Chevron no ethanol works perfect for that.

 

[2nd 392]

Porsche requires high test 93 - Chevron no ethanol works perfect for that.

Kindly explain further— 91– 10% is the best standard pump gas available here and similar elsewhere. How can this be. If 93 was available in all states I would have the tune , except it could have been the factory tune.

 

[BRuby]

Kindly explain further— 91– 10% is the best standard pump gas available here and similar elsewhere. How can this be. If 93 was available in all states I would have the tune , except it could have been the factory tune.

Hmm?

https://en.wikipedia.org/wiki/List_of_U.S._states_by_standard_octane_ratings

Not only that but Canada has plenty of 93 no ethanol too
So really depends where you are and how much you travel
Cali 91 hamstrung unfortunately

 

[2nd 392]

Hmm?

https://en.wikipedia.org/wiki/List_of_U.S._states_by_standard_octane_ratings

Not only that but Canada has plenty of 93 no ethanol too
So really depends where you are and how much you travel
Cali 91 hamstrung unfortunately

Which is why my question, Porsches are sold and used in all states. A sore spot for me having traded a 1 of 500 top tier muscle car (69 GTX, eng ser #HP 360 )sixty something ) for a Harley when we lost it’s min required 100 octane pump gas in the mid 70’s.

 

[stumblinhorse]

Porsche requires high test 93 - Chevron no ethanol works perfect for that.

Like all my vehicles I ran 87 in my 997.2. Ran just fine for the 7 years I owned It.

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