Pinging????

[rando]

My Pathfinder has 150k on it and has started rattling like a chaff-cutter.It is worst between 1200-1950rpm and when the engine is under load,,, hills, acceleration etc.
I fitted a hyclone on the intake a few years ago and it gave me better power and economy.
It has always been a smooth, gutsy, quiet motor, but it appears to be down on power and rattles like a "Salvo's tambourine now .
Why would it start to sound so crook now.
I thought the engine computer adjusted timing automatically to prevent this sort of thing.
My mechanic said i should change to 98 octane, but I have always run standard unleaded( I dont use E10)
Do I need to take it to a Nissan dealer and have the EMS checked?
Any info would be appreciated.
Cheers
rando

[FNQCairns]

If it where mine I would take it to someone who 1.actually knows how to tune an EFI engine and 2. is prepared to re-tune the car above and beyond what any Nissan dealer or any dealer actually.

There is or should be (i dunno your specific car but they mostly are all the same) a couple of factory set screw adjustments that need to be twiddled with an exhaust gas analyser up it's pipe at about the 80-100k km mark, these are often blanked off but the blank can be popped out to give access.

IMO if your has done that sort of km you will be amazed at the results (fuel economy and performance/smoothness) over a 'typical and fully legal tuneup'

cheers fnq

[lethal098]

when was the last time tappets were adjusted???

[rando]

FNQ
G'day mate,
I am not sure what you mean in your reply. Do you mean a "high performance specialist" 4X4 specialist, in short who does the sort of work you advise ???

Lethal
never been done to my knowledge!!!!

Ive just had a major service, new leads ,plugs, injector clean, by Ultratune and was told the EMS basically takes care of "tune" and that a tune-up was, "a thing of the past", so to speak?

By the way it is a 3.2L V6, same engine as a Maxima

[FNQCairns]

Rando there may be a blanked of physical air regulation adjustment up near the airbox close to where some wires terminate, there also may be another one possibly not blanked further downstream near the throttle body and another that adjusts the throttle sensor, I think one possibly 2 of these do not need to be included depending on individual design but I am no expert just observant.
I would place a small bet it does have one or two blanked off do not touch adjustments and the dealers will not normally touch not because it's in your best interests or the environment etc but because lots of regs do not much more than dumb down.

EPA regs or Australian design rules or something to that effect require specific adjustment to be blanked so people cannot play with the physical side of air fuel metering but the problem is cars get older and tolerances change...typical government crap that doesn't deal with what is the real world. The computers etc are pretty dumb and cannot make up now for any physical adjustment that was set 100k km ago, your engine is no longer brand new.

IMO find a small mechanics shop or a performance shop they will probably do the right thing by you.

If you cannot find the out of tune bit that stops the pinging (possibly running too lean) then either higher octane to bandaid the symptom or retard the timing a little to do the same - both are probably going to cost you more for fuel.

Another thought is a dedicated fuel injection specialist?? although i have never had anything to do with them.

cheers fnq

[Noelm]

why not just try the higher octane fuel? easy to do, cost next to nothing and will tell you straight away if you have a timing/pinging issue, then look for remedies or options.

[lethal098]

is it definately pinging??? yes you could try the higher octace fuel to see if it reduces or repairs?? were the correct plugs fitted?? were they gapped correctly??? when you say injector clean i take it you mean something that cost you like $100 (wynss type clean)?? the injectors at that mileage should really be taken out and cleaned and serviced on bench, usully cost bout $30 per injector and then labour to r and r. was it happening before service???
cheers Lee

[rando]

Hi guys
I filled up with 98 octane and the loud rattling has all but stopped I can still "feel"rather than hear, a roughness when accelerating/climbing. I guess I will have to find a good mechanic.
Any suggestions??? I am at the inner northside.

[Benny01]

what model pathfinder is it bud?? sounds to me like you have more than one problem. first thing I would do is stop taking any note of what FNQ is telling ya. secondly check ya hiclone is still in one piece becasue they fly apart all to often and are not nice on motors.

let me know what motor is in it and what year it is

[FNQCairns]

Yeah you could be correct B I am no expert especially on these engines although the advice has been sound in my personal history I still stand by the find someone who knows what they are doing not your typical dealer type run of the mill mechanic...they are everywhere and the advice can be shockingly ordinary.

cheers fnq

[rando]

Benny
2003 model,, last of the old series, 3.2lt v6 petrol.