1999 q45 p1110 valve timing p0325 knock

[qeyeguy]

My car failed emissions because of :

p1110 intake valve timing control LH bank
and
p0325 knock sensor 1 circuit bank 1

my car has been knocking ( sounds like a diesel ) under 1500 rpm and Infiniti had no clue until I said - maybe its the HLA. Oh - that would be expensive to fix.
now it won't pass inspection and I could not even sell it for the $4700 ! blue book, even though it runs well when not idling. . I can not think that it has depreciated that much and has 69k miles!

I have read all over the net about Marvel mystery oil and Gunk and what ever else to clean it out and whether or not the Plenum has to be removed. Maybe I don't put enough miles on it.

Help me Obi -Wan, your my only hope.

[Infinitiexpert]

I'm not sure what is your question, but you should have a tech take a look a the knock problem. It could be something as simple as a oil change or a piston. But I do suggest to try to repair the knocking noise before replacing the knock sensor or the intake valve timing, even thought both components can go bad.

[qeyeguy]

Thank you InfinitExpert. I 've done the oil change. The noise is at low idle and sounds like Tick tick tick, or like a diesel engine. It stops at 1500 and above, which is why I thought the HLA just needed some more pressure.
One mechanic said it is not worth fixing, take it to Infiniti and see what they estimate. Another said he could replace the sensor and do an engine flush and get it to pass inspection for $500.
I don't drive it many miles a week which is one reason I don't mind the low gas mileage. Infiniti says they will 'diagnose it ' for $118, I hope they do more than my $50 OBD reader which gave the same codes as the free inspection station.....
I guess the old days of cars lasting hundreds of thousands of miles are gone?
thank you again for your middle of the night response.

[qeyeguy]

And when I had 3 techs at Infiniti look at the knock noise last year, 2 did not hear anything wrong, so we got the old master mechanic and he said "HLA."
It is so obvious that people always ask "what is wrong with your car?" Makes me have no faith in the dealer mechanics.

[Infinitiexpert]

If is a tick noise, then it may be the lifters, but I haven't seen any bad lifters on that engine. The I35, J30 and early Q45 models had some bad lifter problems but not the 2000 Q engine. Since you don't drive much your Q it is possible that the engine had developed some carbon built up causing the valve no to close all the way up.

I suggest performing the engine decarbonizer flush (I'm not sure if that is the name), but it runs the engine with fuel additives to remove all the carbon from the engine.

Another suggestion is to drive your Q on the freeway, with high octane gas on it, at 3000 RPM or more for at least 30 minutes. It may sound estrange, but I have tried that many times and it works.

[qeyeguy]

will try everything and report back on what works
thanks again

[qeyeguy]

Oil change and after a couple of days the engine light went out. Car still makes the noise on idle. We'll see what the dealer says tomorrow.

[qeyeguy]

dealer says only one code - knock sensor
$200 each, $69 wiring harness
5 hours of work ... he says otherwise it will die on the road and I'll be stuck

my own mechanic says give it a few days and since the light is out, the computer should clear itself and pass inspection. $1,000 saved!