2001 Nissan Stagea pinking (VQ25DD engine)

Page 1 / 3
gregr3, Jan 9, 5:08pm
Bit of a bounce here, still seeing a bit of pinking as described above. I understand that one potential cause of mild detonation could be a build up of carbon in the engine (due to the usage that these get in Japan, lack of proper reving etc etc).

Any suggestions regarding an effective approach for cleaning out these deposits (other than taking it out for a good thrashing, which I will be sure to undertake and enjoy!).

Cheers.

vtecintegra, Jan 9, 5:28pm
I see you mentioned Pac n Save fuel earlier - I've had the occasional bad tank from there so now I just avoid.Has caused issues in both an Avenir with an SR20DET and my current VQ30DD

Haven't had any issues with 95 from other stations, just the Kilburnie Pac n Save

namespace, Jan 9, 7:06pm
It sounds like a highly strung engine that was originally designed to be run on 100 octane Jap fuel, and the engine has aged and gone out of tune a bit over time, there may be no perfect answer here, and 98 octane fuel may not be enough for it.

At the end of the day, pinking is usually caused by too much heat in the cylinders, or using low octane fuel.You could try to cool the engine down a bit, there are special bottles of coolant you can pour into your radiator along with the normal coolant/antifreeze and water.The special coolant will reduce engine temperature.Using colder spark plugs can help (heat range 7+).Or you could try adding octane booster along with 98 gas to try to get the octane up to near 100.

gregr3, Jan 9, 9:03pm
PS:

Oil and filter change - check
New air filter - check
New spark plugs - check
One bottle of injector cleaner - check
No apparent air leaks - check
Premium fuel (95-98) - check
No fault codes - check
Reset ECU - check

esprit, Jan 9, 10:22pm
Direct injection engine. my money's on the inlet manifold and valves being coked up to all hell. Pull the manifold off, de-coke it and get it back to clean again, then blank off all of the EGR bullshit that leads to them getting coked up in the first place.

bigfatmat1, Jan 10, 12:38am
as I mentioned earlier about the evap you will not know if its faulty unless you block it off temporarily because of they way it works. So any means of air leak checking will not show this up including the smoke machine this would be my point of call. Also alot of late model cars pink and as mech says its just how it is.

gregr3, Jan 10, 1:22pm
Thanks for the reminder on that one, will make sure it gets checked!

Question, if this fault was the issue, would it show up by checking the exhaust gas (i.e. engine running lean)!

Also, how big a job is cleaning the inlet manifold (as mentioned above)!

gregr3, Jan 12, 2:04pm
Is it a DIY job to inspect the purge cannister and valve! How accessible are they in these engines!

mechnificent, Jan 12, 3:09pm
If it's an OBDii vehicle the ecu will do quite exacting checks of the entire evap system and should posta code if there is any problem. They open and close valves and monitor the results and deduce if there are blockages, leaks, where the leaks or blockages are. they are really very dependable.
If it's pre OBDii then the checks are to inspect all the hoses, check the valve works(opens and closes), check that the valve is being activated when the motor is warm(temp sensors) the throttle is part open and possible that the car is moving, and check the canister isn't full of petrol.

gregr3, Jan 12, 3:11pm
Anyone know if a 2001 M35 Nissan Stagea (VQ25DD engine) is a OBDii vehicle!

audi_s_ate, Jan 12, 3:21pm
I believe so - most cars post 1996 are. I feel for you - I had an altezza which was pinking under light load. Tried everything you had so far - in the end sold it, wasn't worth the headache.

boardrider, Jan 12, 3:24pm
That's a real shame , was considering buying one.

mechnificent, Jan 12, 3:30pm
The pinking under light load isn't harmful though, lot's of cars do that. If it pinks under a heavier load though, or more specificaly, if it pinks for an extended time, more than a half second to a second, then there is a problem and damage may occur.

I'd imagine that this car will be an OBDii. You can tell by looking for the OBDii connector and then checking which pins it has in it and which are empty. Sometimes they have the OBDii plug but only use it for manufacturers specific diagnostic outpt, in which case they use different pins to the OBDii.

vtecintegra, Jan 12, 3:48pm
I'd start here - I don't think it should be a particularly major job but who knows, the entire engine is buried under a plastic cover after all.I know you can get a product you just put through the intake and it supposedly cleans things out but I don't know how well it really works.

gregr3, Jan 17, 1:38pm
Righto, the next installment has seen the knock sensors replaced. But possibily more relevant was that, given the intake manifold had to come off, the opportunity was taken to give it a good clean out. Apparently it was full of carbon and oil residue (which I understand is not uncommon for these direct injection engines at moderate kms).

Haven't really been able to given it a good test to see if the pinking is sorted (lovely summer weather), time will tell. Thanks to those who suggested having a look at the intake manifold, it was certainly overdue for a clean.

gregr3, Feb 13, 12:05pm
Just a quick follow up, the above work has definitely improved the performance of the car. Although one interesting thing to note is that I was forced to tip a bit of 95/96 petrol into the tank yesterday (as opposed to 98) and it brought back a bit of pinking.

So the lesson! There's premium gas, and there's PREMIUM gas, 98 all the way.

gregr3, Dec 4, 12:44am
Any experiences out there with these engines pinking, and what the eventual solution was!

Vehicle was recently imported, 84,000 km.

Running premium petrol, no codes coming up on the computer.

Cheers.

namespace, Dec 4, 12:51am
I'm no expert, bit I'd recommend changing to colder spark plugs like NGK Laser Iridium or Laser Platinum heat range 6 or 7, and also only run the car on BP 98 or similar 98 octane fuel.

gregr3, Dec 4, 1:02am
Yep, am in the process of changing the plugs to the recommended NGK ones (iridium). Was intending to get a mechanic mate to help out, but though I might have a look under the plastic to see how hard it could be (this was an understatement, could barely see the plugs for all the gear on top!).

One question in my mind is whether or not using 95 (what Pak n Save and New World dish up) instead of 98 would make a difference with this.

phillip.weston, Dec 4, 5:31am
Got a friend with the same vehicle which is doing the same - I changed the plugs on it and he switched to 98 octane and it seems to have helped but didn't take long for it to start pinking again. If you can find a solution I will be all ears!

I'm thinking maybe change the thermostat for a cooler one so the engine runs a little cooler and less prone to pinking - the plug that they use is a specialist plug and am unsure if they come available in a colder heat range.

phillip.weston, Dec 4, 5:32am
oh yeah plugs aren't too hard to replace - just undo the 10mm bolts on the coil packs and pull them out, I think on one side you had to undo a 10mm nut/bolt which secured in the wiring loom bracket but other than that fairly straight forward. It is tight on one or two of the plugs though, best to use a 3/8" drive ratchet.

gregr3, Dec 4, 12:00pm
Yeah, saw one of your earlier threads about that, was curious about how it turned out.

The plugs I got were LFR5AIX-11 (as per NGK recommendation).

paclark, Dec 4, 12:54pm
My VQ30 Maxima was pinging really bad under load. The MAF ( Mass airlow sensor ) was replaced and pinging gone. If its not this it may be the oxygen sensors in the exhaust system are stuffed.

zephyrheaven, Dec 4, 1:35pm
Have seen a few of these with cam chain stretch, not pretty

gregr3, Dec 4, 6:23pm
So therefore it'd be a tensioner issue!