Well the new factory engine swap for my 6spd 2002 Maxima was completed about a month ago. So far there doesn't seem to be any major problems except for a subtle sound that was being made in the engine compartment. Over the past few weeks the noise became louder and louder. Given all the work that must have been done around the engine is suspected perhaps they had not tightened the exhaust headers, or some other pipes in the exhaust system. At times it sounded like I had rattlesnakes living in my Maxima engine bay. I figured that over time some pipe had loosened itself and the rattle was getting louder and louder. The strange part was that the sound seems to have a resonance point at around 2500 rpm. Up hills or under load the sound would start up. At around 3000 rpm the sound would suddenly disappear and at higher revs even if I mashed the pedal next to no sound would be heard.

This week it got to the point that I decided to take the car back to the dealer. The tech was asked to come for a ride with me to confirm the noise. Back at the shop, after confirming the noise, he was instructed to hoist up the car and look for any lose parts. And this is where it gets interesting. He comes back and informs the service manager and I that the problem is engine knock!!!

In total disbelieve I argue how that is possible since I've only ever used premium 91 octane gas from Petro Canada in Toronto, Ontario and my old engine never made this kind of sound (for that matter no car I've ever had has done this). I ask for a second opinion and the service manager gets out his master mechanic and we go for a drive. Once again this mechanic comes up with the same conclusion... Engine Knock that sounds like the noise a chain makes as your pulling up a boat anchor. He explains to me that on aluminum engine the sound is amplified due the material! At this point I was not arguing anymore and listened to their recommendations. It turns out that in their opinion Petro Canada gas is garbage. They are suggesting using Pioneer 93 octane or Sunoco Ultra 94 octane.

So I had about 1/2 a tank left and there was a Sunoco around the corner. I managed to squeeze in about 33 liters and off I went. It might just be my ears, but I think the knock seems to have gone down in intensity and duration. I'm still somewhat in disbelieve but hey I won't argue against two factory trained Nissan techs...

What do you guys think?

wolfman (who's living with rattle snakes and boat anchors....)

 

I've heard of other people with 3.5L 5th gens having chronic engine knocking even under premium gas... not sure if anyone's come up with an ultimate solution.

 

I have a hard time with the dealer's claim. I mean, isn't 91 considered premium? Isnt' that what the manual requires?

Here, in Alberta (home of gas as it were) 91 is about the highest I could buy, and I don't have any knock with it. In fact, I think the last tank was 87 (Saveon Foods pump probllem) and I noticed no knock of any type.

so I'd say there's still a problem the dealer should address. It should run properly without having to find 93 or 94 octane.

Jerry

 

Thats crap..I use Esso's 91 octane all the time...once in a blue moon i put in 93 from Sunoco...I dont have an engine knock problem

 

You've got a an '01 though. My 2k2 pings lightly on Shell 91, but when the car was new, it wouldn't ping on 87.

 

my cousins 2002 max knocks quite a bit and the sound is similar to how you describe wolfman.

It is strange because his car has obviously been knocking ever since he bought it because he doesnt hear anything abnormal and claims that he has always put premium gas in it...

After driving my 2003 max daily whenever I ride in his car I notice the occassional knocking, mainly while accelerating or in certain rpm range perhaps... never really studied it much.

 

I've noticed more pinging as my miles rack up. I did notice another 5.5 gen Max in traffic on the freeway the other day and heard his Max pinging upon acceleration. I've done a full induction system, been thru 5 different intakes (and back to stock again), replaced the spark plugs and I've always ran Chevron 91 premium. There is 100 octane 76 racing gas by my house but I can't afford $4.99 a gallon.

 

subject is on the 3.5L 5.5 gen Maximas.

 

Guess I've been lucky...2k2 6spd, 52k and I use 89 octane all the time..never had a knock at all.

 

all i can get here in New Mexico is 91 octane, and in 22xxx miles i have never had any knock, but from your description i can tell you that it is knock. a buddy of mine has a mean knock problem wth his 01 mustang gt, exactly the same sound low to mid rpm knock, nothin in high rpms and nothin when he stomps it......... the altitude could have something to do with it too.......................

just my $.02

WHEELMAN

 

this isnt reassuring, i'm at 31xxx running 91 (cuz i'm in cali) this thing better outlast the tranny

 

I only have to wonder what kind of damage this is causing inside the engine. Well I got Nissan to replace my old engine under powertrain warrenty for high oil consumption (engine replaced at 90K km). I wonder if they will do anything about this knocking? Damn they fix one thing for me and give me a whole new problem to deal with.

I have to say though I was always quite suprised to see the high compression ratio of 10.5:1 (if i recall correctly) that Nissan disigned these engines with. I'll have to see if this Sunoco 94 makes things better. I don't mind running this gas given that is about the same price as the 91 stuff. Once the engine ages and becomes even more knock prone what am I do then...I guess I'll be running rocket fuel...

wolfman

 

my 2k2 engine pings on cheap gas so i only put 91 (the highest i could buy here in ca) and it disapears.

 

You guys with the knock/ping issues are getting my nervous. I havent had this problem (knock on wood) but then again, I pretty much only use Sunoco Ultra (94) or Hess Super (93).

 

I can run as low as 87 or 89 in mine and it never knocks.

 

93 Down here in Florida all day, no pinging at all......

 

I have the same problem. Always use 91 in my 2002 and I get this annoying ping/knock while accelerating. Nissan mechanic hears it too but has no answeres. I tried a fuel treatment system. BKG-44 I think it was called. It completely fixed the problem for the next 3 tank fulls of gas. After that all the knocks came back. At ~25 dollars a can I can't afford to constantly drop this stuff into the tank. I really wish I could find a fix for this.

 

If you are getting pinging even with a high octane fuel, I highly recommend replacing the knock sensor. The knock sensor is really just a microphone that the computer uses to detect engine noise which "fits" a specified cycle which is consistent with knock. If the microphone goes bad, the computer won't detect knock. I'm sure your rebuilt engine is still using the old/original knock sensor. If that sensor was dropped by accident during the swap, it could have been damaged.

 

She needs premium, dude! PREMIUM!!! *shakes fist*

 

The presumption is that wolfman was using the same fuel both before and after the engine swap. Since the ECM is the same, the logical conclusion as to why he now has knock with the new engine is a damaged sensor.

 

I had a similar problemt o you, and I am in Mississauga ontario. Please join www.torontomaxima.com

As for your problem, it sounds more like the rear cat. I had the same problem at exactly the same RPMS. Took it to Alta Nissan woodbridge and they immediately, without further inspection assumed the rear precat on the manifold. AFter it was ordered underwarranty. it was gone!!

That may be the case wit hyou as well

 

Thanks for the info MiniRX7. Looking at my parts list the following items were replaced:

1 20800-5Y525 CONVERTER
1 20020-5Y700 TUBE
1 226A0-5Y701 SENSOR
1 226A1-5Y701 SENSOR
1 10102-CB6A0 ENGINE, BARE
9 GASKETS
1 B08A1-5Y700 CONVERTER
1 208A2-5Y826 CONVERTER

Note sure if the item you mentioned is included.

 

I have to agree with you ABS, this seems the most logical conclusion. I'm down to 1/4 tank 91 Oct PetCan and 3/4 tank 94 Oct Sunoc. Pinging still there, although intensity and duration vastly deminished. Engine seems to pull harder than before with old engine after about 3K rpm.

wolfman

 

My 2K2 Max used to knock maybe a year ago in hot weather during light acceleration when running on 91 or 92 octane gas. I took it into the dealer for the "lack of power" TSB since I had experienced the weird accelerator hesitatation at least twice. They changed the MAF sensor and reprogrammed the ECU. It seems like that pretty much fixed the prob. I almost never hear any now.

However, I don't drive my Max much anymore.

 

Check if any of your exhaust components are hitting the heat shields.....

 

You guys are scarin me! I only have access to 91 octane in Colorado, so I hope I don't need any higher. I have not noticed ANY knocking at all, but have never run below 91. Some have said that it gets more noticeable as the miles go up.....how many miles did you start noticing? I'm only at 24K. I am also about ready to start thinking about some mild mods, but if I'm going to start pinging.....I might have to consider "plan b"!

 

CHECK THE POST ABOVE!