2000 FY33 Valve train noise

[xhristimatt]

2000 FY33, almost 170,000 miles. At warm-idle, I have a distinct knocking noise that appears to be coming from the passenger side intake camshaft advance sprocket. This only occurs only at idle and when the engine is warmed up and disappears when the engine is revved. Otherwise the car runs well.

Appears to be a function of oil pressure/viscosity. The problem appears to be with the Intake Valve Timing Solenoid Valve. At warm idle, when I jumper the directly to the battery, the noise disappears instantly, which to me indicates that that the advance sprocket is working correctly. There is 12+VDC at the connector to the solenoid valve, so it doesn't make sense. The connector appears clean etc and in good shape. Another thing that I noticed is that the FSM clearly states that there are two o-rings on the solenoid valve. When I pulled it out, there appears to be only one and it was at the top of the threads for the valve. I looked into the hole and there does not appear to be any o-ring stuck in there. I tried putting an off-the shelf O-ring on the valve body at the end of the plastic screen piece, however it had no effect on the knocking noise.

Does anyone have any suggestions? I've searched unsuccessfully on the forum for a discussion on this topic, however I'm certain that this must have come up before since there are several You-tube videos that document the exact noise that I am experiencing.

Tim

[Skibane]

There is 12+VDC at the connector to the solenoid valve, so it doesn't make sense.

Not sure about this particular one, but some solenoids are controlled by grounding (or ungrounding) the negative wire. The positive side is always "hot".

[xhristimatt]

SO no joy so far; I'll try another tact. Does anyone know of a source for a technical discussion of the operational details N-VCT system is installed in the FY33? I would like to determine how this solenoid works; i.e. is it either ON of OFF or are there intermediate settings for cam advance?

Also; there used to be a shop in the Atlanta area that seemed to specialize in working on these cars. Perhaps they would be a source of info. Are they still around and what is their name?

Anyone?

[paranoidjack]

I have the same problem.

Same.

Passenger side.

After oil changes it appears to subside.

After long highway rides it seems to subside.

I also have the code for same sensor. I have replaced it with another sensor that was on my old motor, and same problem, same code.

Very eager to hear of your progress. I'm going to have my motor flushed, because I can't help but deny that this problems subsides with clean oil...it was a junkyard motor, maybe it's just filthy...

[xhristimatt]

Our symptoms are an exact match. Yes, the problem greatly decreases when I change oil however it returns after a few days. Not sure an oil flush will help. On my old G50, I experienced the same thing, sometime after reaching 200k miles, did the engine flush and it got worse, however switching to a less viscous oil (5W40) virtually eliminated the noise. Higher viscosity made it worse. This time, with the Y33 switching to the less viscous oil did not provide a lasting solution

What code and what sensor are you describing? I have not pulled codes yet.

[Infinitiguy19]

Oil pressure at idle (cold-hot) with new oil and filter?

[xhristimatt]

Oil pressure at idle (cold-hot) with new oil and filter?

I have not measured oil pressure. Oil pressure is not the problem; 1) Only the right bank is affected 2) I can make the noise go away by energizing the right side camshaft advance solenoid directly from the battery. 3) The oil pressure idiot light does not come on at hot idle - 650 RPM.

I really need to understand how the ECU control circuit works for camshaft advance. Are there only two positions for camshaft advance (vs engine speed) or is it infinitely variable within the advance range?

[paranoidjack]

I replaced the intake valve timing control sensor - seen here:

Just above the oil dipstick, tall sensor with the oil stain on bottom half.

I am very curious to know how you gave +12v to the right side camshaft advance solenoid - are we talking about the same sensor?

My friends have told me the motor is junk. I don't buy it. If the motor is capable of being silent as designed when the sensor "wants" to work, then I don't think there's a legitimate mechanical fault. Though it is a really nasty noise.

I was going to test oil pressure. Just because one side is making the knock doesn't mean oil pressure isn't low - could be a longer oil passage, more clogged up, number of things, IMO, it's worth testing. I bought the gauge and am going to find time to test asap. Perhaps oil sump is clogged and affecting one side more than the other? Can you elaborate on what you jumped to +12v?

Thanks, and let's figure this one out dude...!!!

[xhristimatt]

The part you describe in your pic is the same except that my noise is coming from the passenger side cylinder bank. On that side the camshaft advance solenoid valve is located just behind the alternator just inboard of the oil fill cap. All I did was to run the engine and use a voltmeter to determine which pin on the wiring harness gave me +12V, then I ran a hot wire from the positive terminal on the battery to the corresponding pin on the solenoid and grounded the other pin on the solenoid. When I did this with the engine running, the ticking noise went away immediately. As soon as i pulled the jumper wire off the noise came back immediately. The only difference that I could see was that the direct jumper from the battery provides over 14V, while the voltage coming from the wiring harness provides 11.9V. Not sure what this means. Thats why I'd like to determine whether this valve is either on/off or whether it has a variable function over its operational range.

[xhristimatt]

Jack:
Is yours making noise on both sides or on one side side only (like mine) If it is only one side, one thing that you might try if you have both solenoid valves exposed is to swap them and see if the noise changes sides with the swap (I think both banks use the same part). I would do that but I'd have to take off a whole bunch of stuff to get at the one on the driver-side bank and I'm lazy.

[paranoidjack]

Just driver's side. I'll have a look and see if a swap can be done. Take a look tomorrow if I'm not sick as hell, think I caught my gf's bug.

[xhristimatt]

Well, I think I've found at least a temporary solution. As I said in an earlier post, I was able to get the clackety noise to go away instantly by energizing the passenger side cam advance solenoid directly from the battery. After fooling around with it some more and trying a new solenoid ($130 wasted), I've concluded that the path to ground, somewhere between the solenoid connector to ground is not continuous. I don't know whether its a bad connection at the connector (which appears to be in good shape), a problem in the wiring harness, a bad relay in some unknown location (ECU?) etc. Whatever the case, I'm not getting a good ground.

What I did: I verified that I had voltage (12V) to the harness connector for the solenoid when the key is on, and that the signal to the driver's side solenoid (which works fine) is the same as the non-working side. Since I now have an extra solenoid valve, I cut away some of the plastic on the original solenoid at the end where it fits with the harness connector. Then on the harness side I inserted a wire into the harness connector where it accepts the grounding pin of the solenoid. Its kinda hard to describe, but the idea is that when I insert connector harness connector into the solenoid, I have a wire pig-tailed off the ground connection. The other end of this wire I grounded to the closest engine screw. Voila, no noise, smooth as silk. The solenoid now gets power from the harness and is grounded directly to the engine instead of through the harness/relay/ECU. The solenoid is always energized when the key is on, and de-energized when the key is off.

So now, I wish I could find some definitive information regarding how the variable valve timing works.
1. Does it advance the cam hydraulically strictly based on oil pressure which is related to RPM or is there some sort of electronic throttling of the advance???
2. Is there a relay somewhere in the cam-advance solenoid circuit? Where would this relay be located?
3. Where can wiring harness connectors be purchased?

C'mon now! Help me out. Someone has to know the answers to these questions. I'm providing substance here by providing an actual solution to a problem common to the y33 cars. I'm a little disappointed; this forum used to be a helluva lot more helpful on technical issues a few years back when I had my G50. It seems more like a social chat room with little substance and plenty of BS anymore. One guy on here was advised that his engine was shot due to this same problem!

Tim

[Infinitiguy19]

I am not sure if you have read the service manual or not?

EC-365--EC-372 describes in great detail of the Intake Valve Timing (IVT) solenoids.

Do you have any codes?

Basically you have a broken wire somewhere as the ECU grounds the solenoid to command it on/off.

Check the continuity of the pin 25 on the ECU and pin 2 of the IVT solenoid.

[paranoidjack]

Well, thanks for posting back that info Matt. I DID put 12v to it, but it made no difference, even though I also grounded it to the battery.

Hmmm.....like infinitiguy said, did you have codes? Now that it's getting warmer out I can't wait to get into this. Been sidetracked with home improvement projects.

My car is rotting out from within. At 245k, I don't think she'll see 300. Starting to develop rust on wheel wells, front and rear, and the subframe is so bad I can't jack it up in parts or it crushes. Sadly, having this car since 72k, soon I have to let her go for the only thing not worth fixing - the body.

That being said, I'd love for it to run better before I trade it in