2000 Cedric (Infiniti M 45) is pinging badly - HELP!

[sjoy]

Hi All,

I really really like the 2000 Cedric I bought 6 months ago. The only problem I've run into is that it 'pings' (we called that Octane knock in the US - in New Zealand they call it pinging). It has got a VQ 25 DD Y-34 engine.

I've tried 98 Octane to cure the problem with little success. Cleaning the Mass Air Flow sensor helps quite a lot, but the problem seems to come back within a few weeks or when I switch to another brand of gasoline.I'm considering a new MAF sensor and then perhaps the knock sensors if that doesn't work. Has anyone had a similar experience with this car? I'm looking for a permanent fix. Also - I'm wondering if the city smog might have something to do with it? Perhpas continually contaminating the MAF?

Thanks for any help.

Steve

[szh]

(I am assuming that the car is tuned properly and the plugs are not fouled and air cleaner is okay, etc.)

Then this is a complete SWAG: you may have some carbon build-up inside the engine and on the valves, etc.

Try putting a can of BG44K through to clean stuff out. Or the Nissan equivalent cleaner available from dealers (the BG44K is a known item, not as sure of the Nissan one).

Again, this is a total guess ... but it could be a cheap fix.

Z

[Q451990]

I agree on the idea of carbon build up on the valves or intake... possibly dirty injectors. Still a wild guess, but that's the direction I would go.

As far as a MAF or knock sensors, I think your ECU would be advanced enough to pick up issues there. If you have been reading the old posts on the G50, keep in mind that the 90-95 ECUs were OBDI and pretty dumb compared to today's ECUs.

Heath

[sjoy]

Thanks for the input fellas. I'll give the BG44K a try and see how it goes. I read a post some months ago about someone cleaning carbon buildup by somehow feeding a gardenhose and dishwasher soap into his engine while running. Is this idea rediculous or genius?

By the way - new iridium NGk plugs and new air filter.

Steve

[szh]

Are those the Nissan OEM spark plugs? I don't know much at all about your specific engine, but many Nissan engine models are notoriously sensitive to the brand of plug you use. Bosch is a complete no-no, for example. If yours are OEM, and the gaps are okay, then this is probably not the source of the pinging, though.

So ... if BG44K does not cure the problem, then I'd start looking at the knock sensor (as you also mentioned) and going from there ...

One other thought, you don't have a K&N oiled air filter do you? The oil has a tendency to come off the filter in micro-droplets that land on the MAF, coat it, and result in very strange engine performance.

Z

P.S. I have never heard of the dishwasher approach to carbon removal. Sounds like a good way to kill your engine, frankly!

[Q451990]

I read a post some months ago about someone cleaning carbon buildup by somehow feeding a gardenhose and dishwasher soap into his engine while running. Is this idea rediculous or genius?

Let's don't even discuss this

Heath

[DrewQ45]

I read a post some months ago about someone cleaning carbon buildup by somehow feeding a gardenhose and dishwasher soap into his engine while running. Is this idea rediculous or genius?

Are you trolling us?

[sjoy]

The plugs are OEM and top of the line as far as I understand it. They are the same as I pulled out of the car when I purchased and I think those were the originals. The air filter is just paper I think. I'm going to try to import some GB44k into New Zealand. It gets quite a bit of praise on the net.

I read about the garden hose and soap idea on another forum. Apparently it worked quite well from what I remember. The guy kept the vehicle at a low idle and bit by but dribbled a soapy water solution into the engine somehow - through his fuel injectors initially I believe. He said the secret was to use very little soap and water at a time. I tried to track down the thread but couldn't.

Cheers

[szh]

The plugs are OEM and top of the line as far as I understand it. They are the same as I pulled out of the car when I purchased and I think those were the originals. The air filter is just paper I think.

Okay, good.

I'm going to try to import some GB44k into New Zealand. It gets quite a bit of praise on the net.

Well worth it! Only one thing ... it is BG44K, just mentioning it in case a search for the other name fails.

I was confused by the earlier New Zealand reference, because your info shows "Ann Arbor, MI". Did you move down there recently? Is it as beautiful as portrayed?

I read about the garden hose and soap idea on another forum. Apparently it worked quite well from what I remember. The guy kept the vehicle at a low idle and bit by but dribbled a soapy water solution into the engine somehow - through his fuel injectors initially I believe. He said the secret was to use very little soap and water at a time. I tried to track down the thread but couldn't.

Uh ... okay ... but I remain skeptical. I don't plan to do it to my engine ever.

Z

[bullittandy]

The plugs are OEM and top of the line as far as I understand it. They are the same as I pulled out of the car when I purchased and I think those were the originals. The air filter is just paper I think. I'm going to try to import some GB44k into New Zealand. It gets quite a bit of praise on the net.

I read about the garden hose and soap idea on another forum. Apparently it worked quite well from what I remember. The guy kept the vehicle at a low idle and bit by but dribbled a soapy water solution into the engine somehow - through his fuel injectors initially I believe. He said the secret was to use very little soap and water at a time. I tried to track down the thread but couldn't.

Cheers

This was an old fix on carbed cars, you dribble water straight into the carb and it vaporizes in the engine, and theoretically cleaning the carbon off with steam.

I did it one time on my 55 Chevy and it blew a whole mess of black smoke afterwards on full throttle so it probably works.

I can't imagine how toy could do it on a fuelie.

[elwesso]

Why woudl you do that when you have products that are made for that.

many people sell carbon remover. One thing Ive used with good sucess is GM top engine cleaner. They sell it in an aerosol and a liquid, you want the liquid. They use it on the northstar motors on Cadillacs, which since granny and gramps dont ever go past 2000 RPMs they get mad carbon buildups.

Id run a can of top engine cleaner through it (or equivalent, im sure every brand has their own). Put it in through the brake booster hose.

After you do that, i think just giving it the Italian tuneup would be the way to go. In other words, it needs to see HIGH RPMs and high loads to blow all that crap out of there. once you run the stuff through it, take it out put it in 2nd gear and gun it to the redline and then (dont shift) let it fall down slightly, then gun it again.

I bet the car is driven in the city and has been most of its life. With about every motor in existance now, they HAVE to be driven hard occasionally or theyll run like crap. I even see this in marine motors with rentals. The renters always putt-putt around the lakes and it glazes the cylinders. If theyre run hard just occasionally it really helps.

I drive my Q in the city but I take it out at least every week for a good flogging. its fun, and I can justify it because it blows the carbon out!!

VQ25DD engine???? Are you serious?

[maxnix]

I read a post some months ago about someone cleaning carbon buildup by somehow feeding a gardenhose and dishwasher soap into his engine while running. Is this idea rediculous or genius?

Does the term hydrolock mean anything to you?

[ScottJackson]

I've done the old style carbon removal with water thing lots of times, and even on the Q. You want it about 2000rpms or so and you fill a 2 liter soda bottle (or similar) with water. Run a hose from the plenum to the bottle of water. I use the brake booster port on the plenum. Pinch off the hose with vice grips, start the car, use both hands to replace vice grips with pliers, then with one hand on the pliers and one on the throttle, slowly feed the water into the engine while making sure it stays revved up. Simple as that.

[sjoy]

Wow. Thanks for all the tips.

As to being in New Zealand - yes it is absolutely amazing here and I love looking out every day to the ocean and mountians from my back porch. I went to school in Ann Arbor but moved a year ago.

Back to the car: One reply was quite correct - it is mostly city driving in the lower RPM range. The roads in NZ aren't nice big highways like the US and I never get the car going too fast for too long.

I have tried 'off the shelf' carbon buildup removers (STP etc.) but they don't really seem to do anything. The only thing that has helped has been cleaning the Mass Air Flow sensor with a special MAFS cleaner. That works for a few weeks or a month. Also, the pinging seems to happen more when it is warm out, not so much when it is cold.

I tried a bit of an "Italian Tune up" today as I drove to work and back (as much as the roads allowed, anyway) and didn't notice much difference.

I haven't had any luck yet on finding someone to import the BG44K but that may be my next step.

I was interested to see that someone had used the 'run water through the engine solution' for this problem - though I'm not sure I'm tech savvy enough to pull it off. I remain a bit confused thought - is the idea to use soapy water or hot steaming water?

Any more responses on those lines or any other suggestions would be much appreciated.

Cheers

[elwesso]

just a few blasts in 1st gear will do it... Find something that you can run through the intake.