Nissan Murano Forum banner

1 - 20 of 37 Posts

·
Registered
Joined
·
6 Posts
Discussion Starter · #1 ·
Is anyone having "pinging" problems also known as Engine Knock?
I am supposed to be able to run regular gasoline but it pings like crazy when I do. The dealership tells me to run premium.

2005 SL AWD
All Options
 

·
Moderator
Joined
·
5,244 Posts
I tried regular, mid-grade and premuim - no "pinging" whatsoever. The only difference I see is slight performance decrease under heavy acceleration when using regular
 

·
Registered
Joined
·
12,512 Posts
danno-

The MO, like most modern day engines, is equipped with knock sensors, which will retard the engine timing whenever pre-ignition (knock) is detected.

If you are running regular gas from a reliable station you should NOT be experiencing knocking. The dealer is blowing you off; you do not need to run premium. There is something wrong and they should investigate and repair the problem.

The following is from page 9-3 of the 2005 Owners Manual:

"FUEL RECOMMENDATION
Use unleaded regular gasoline with an octane
rating of at least 87 AKI (Anti-Knock
Index) number (Research octane number
91).
For improved vehicle performance,
NISSAN recommends the use of unleaded
premium gasoline with an octane rating of
at least 91 AKI number (Research octane
number 96)."



-njjoe
 

·
Registered
Joined
·
781 Posts
njjoe said:
danno-

The MO, like most modern day engines, is equipped with knock sensors, which will retard the engine timing whenever pre-ignition (knock) is detected.

If you are running regular gas from a reliable station you should NOT be experiencing knocking. The dealer is blowing you off; you do not need to run premium. There is something wrong and they should investigate and repair the problem.

-njjoe
The knock sensor is detecting knock and I'd guess is retarding the timing. With higher octane fuel you can run more advanced timing - which leads to better porformance.

I don't know how the knock sensor on the VQ engine works but my understanding is it will all allow a certain degree of knock for a given amount of time before the ECU will retard timing.
 

·
Registered
Joined
·
142 Posts
danno said:
Is anyone having "pinging" problems also known as Engine Knock?
I am supposed to be able to run regular gasoline but it pings like crazy when I do. The dealership tells me to run premium.

2005 SL AWD
All Options
what exactly is that "engine pinging"? how do you know if your car has it? can you hear/feel it?
thanks
 

·
Registered
Joined
·
4,077 Posts
You could also try 2-3 more tank fulls from another station/brand too just to ensure its not the gas itself.

When you say pinging like crazy what does that mean? Under what conditions? (heavy acceleration, on highway, up high etc.)
 

·
Registered
Joined
·
6 Posts
Discussion Starter · #9 ·
Gonzo said:
You could also try 2-3 more tank fulls from another station/brand too just to ensure its not the gas itself.

When you say pinging like crazy what does that mean? Under what conditions? (heavy acceleration, on highway, up high etc.)
Under slower acceleration, around slow corners, etc.
 

·
Registered
Joined
·
6 Posts
Discussion Starter · #10 ·
Re: Re: Engine Knock

andy said:


what exactly is that "engine pinging"? how do you know if your car has it? can you hear/feel it?
thanks
You'll know.
Its a sort of knocking noise coming from engine.
The power is also a little sluggish when this happens.
 

·
Registered
Joined
·
6 Posts
Discussion Starter · #11 ·
njjoe said:
danno-

The MO, like most modern day engines, is equipped with knock sensors, which will retard the engine timing whenever pre-ignition (knock) is detected.

If you are running regular gas from a reliable station you should NOT be experiencing knocking. The dealer is blowing you off; you do not need to run premium. There is something wrong and they should investigate and repair the problem.

The following is from page 9-3 of the 2005 Owners Manual:

"FUEL RECOMMENDATION
Use unleaded regular gasoline with an octane
rating of at least 87 AKI (Anti-Knock
Index) number (Research octane number
91).
For improved vehicle performance,
NISSAN recommends the use of unleaded
premium gasoline with an octane rating of
at least 91 AKI number (Research octane
number 96)."



-njjoe
\
God knows I have made these exact statements to the dealer.
I think they get kickbacks for NOT doing warranty work.
 

·
Registered
Joined
·
3,257 Posts
Sounds to me like several knock sensors are bad around here.

This happens.

Also it sounds like there is at least one defective dealership.
That is real common with Nissans.

The knock sensors work real well.
I can run 87 octane at 98F, and get NO knock when accelerating.

Certainly in cooler weather you should have no problem.

There can be extenuating circumstances.........engine carboned up etc, but that is extremely rare and I don't think you will see it in modern cars.
It is also possible I would think that a bad ECU could advance the timing too far, or not retard the timing even though it was getting a signal from the Knock Sensor to do so.......

But in the end, the Murano was designed with an adaptive engine.
You paid for it and if I were you I would make sure I got it.

Homer
 

·
Registered
Joined
·
12,512 Posts
Hey guys, it is this simple: If you are running 87 octane and your engine is truly knocking, then you definitely have a problem somewhere under the hood.

Even if you are running a tank of poor quality gas, a fully functional VQ engine will make the necessary timing adjustments to eliminate the pre-ignition condition.

If your car is under warranty have the dealer fix it. If he simply tells you to run premium gas then he is obviously a lazy S.O.B. who doesn't give a damn about customer service, and shouldn't have the privilege of your business.

The following excerpt is from page EC-26 of the Service Manual:
"The knock sensor retard system is designed only for emergencies. The basic ignition timing is programmed
within the anti-knocking zone, if recommended fuel is used under dry conditions. The retard system does not
operate under normal driving conditions. If engine knocking occurs, the knock sensor monitors the condition.
The signal is transmitted to the ECM. The ECM retards the ignition timing to eliminate the knocking condition."

-njjoe
 

·
Registered
Joined
·
155 Posts
danno, I've had the exact same problem and gootten the exact same response from the dealer : you need to run premium fuel.

I did try premium fuel. The knock went away. But I'm sill pissed. Unlike our American friends, we pay a big premium for premium fuel.
 

·
Registered
Joined
·
416 Posts
danno - another fuel option in Winnipeg is Mohawks "gasohol" ....the 10% ethanol raises the octane rating and costs "regular" price...also provides fuel line freezing protection....I haven't used it because I don't have "pinging" even on regular 87 octane...just a thought...
 

·
Registered
Joined
·
23 Posts
What exactly does knocking/pinging sound like? I've never had a car that did it before but I think my MO is doing it and I use regular. What I hear is a rattling kind of sound only when accelerating at low rpms, sort of like a stuttering. Kind of quiet and subtle and more noticeable with the windows down. I don't think the engine is misfiring because I don't feel a hesitation in the acceleration when it happens. I guess it could be in the exhaust train or transmission but I want to eliminate the possibility that it is knocking or pinging.
 

·
Registered
Joined
·
3,257 Posts
Often it sounds like a few pebbles in a tin can being shaken vigorously.
Yes, it is a rattling sound.

Homer
 

·
Registered
Joined
·
23 Posts
OK, well, the official response from my dealer is that you need to use premium (91) gas. When I confronted them with the confusing statements in the owner's manual they claimed that the octane number at the pump is what Nissan is calling the "research octane number" in their recommendation. I still think this is crap, I have never heard of 96 octane gas, which, if you read the owner's manual and go by the research octance #, Nissan recommends for "increased performance". My MO seems to run fine on 89, I haven't tried 91 yet but I will.

My personal opinion based on what people have reported on this website and what I've found with my MO, is that:

1) The Murano is designed to run on 91 octane gas because of the high compression ratio and the CVT which likes to keep the rpm's low.

2) Some owners can run theirs on 87 with no pinging, most can run 89, seems to depend on the individual car.

3) Nissan corporate is guilty of false advertising, or at least confusing explanations, when it comes to what type of gas to use. Their sales force is also totally ignorant about this subject since they all like to claim that the MO runs fine on regular. Most car reviews on the MO erroneously claim it runs on regular as well

For me, I'll just have to see if the mileage gets better with premium- otherwise I will feel like I was totally cheated re: the fuel costs for this vehicle. I probably would not have bought the MO if I knew this ahead of time. Needing to put premium in a sports car (like the Z) is expected, needing to use it to run a SUV-like family car seems like a big waste.:3:
 

·
Premium Member
Joined
·
2,049 Posts
High compression is high compression.
The VQ wants high octane. It can do with regular as some of our members have said that do use it.
A while back we tossed this around in a few other threads.
Sure, it can retard the advance and run regular.
I want mine to live where it wants to without having to adjust to a less peppy state.
Besides, the cost of premium isn't that much more--not when you consider your payments and insurance differance over a standard car.

;)
 
1 - 20 of 37 Posts
Top