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Cam Variator

159K views 224 replies 58 participants last post by  Sakyubasu 
#1 ·
My local mechanic said I might have a faulty cam variator. Anyone has this problem? please advise?
 
#5 ·
Yes, it's a known problem that so far has typically shown itself on the QP Duo and 4200 models. If you hear top end noise / clicking etc that is persistant (i.e. not just for a minute or two at startup) or get a related code pop up on your car, get it fixed right away.

Many times you can diagnose wheter it's the variator itself or the sensor by disconnecting the plug to the sensors and driving the car, if the noise quiets, the car has reverted to it's default / safe timing and it's likely going to be the sensor.

However if it still makes noise, you may have a fault in the variator itself or you may have already caused a bit of damage and even though the variator positions to the default / safe position the noise will persist.

Hope that helps!

Best Regards,
-- Jeff
 
#8 ·
Not a good idea unless you are proficient in timing Ferrari engines.

Complaint - chatter on cold start that gets progressively worse, can sometimes fade with engine warm up but never really goes away. Sometimes can hear a misfire through exhaust.

Repair - cam variators and variator solenoids removed. Variators sent to MNA, they send to their machine shop and repair, then send back to dealer. New solenoids and repaired variators installed - engine re-timed. Car will be down for several days. Once MNA gets the variators it can be as quick as a two day or as long as 5 days to see the parts again. We have not noticed any reoccuring symptoms once this proceedure has been done.
 
#7 ·
I would not attempt the repair by yourself unless you are quite used to working on modern cars, have the tools and skills necessary to complete the job and understand the problem / solution I've described.

i.e. By the small amount of direction I've provided... you can say, no problem, I can do that.

If you're not sure, take it to a quality service center and let them know a hint as to what the problem may be... they may not be familiar with this problem for the Maserati, but they will understand how to fix it based on their industry training.

Best Regards,
-- Jeff
 
#9 ·
OK, experienced mechanic here, but not experienced with this type of set-up.

Does anyone have a shop pic or actual picture that shows how this technolody is deployed on the Mas? Is it for two or four of the cams? Is is electriconally driven or inerita (the solenoid word makes my think electical but struggling to imagain how that would be integrated into the taiming system)?

Jeff, where are the sensors you are referring to?

Any known contributors alluded to by MNA? Oil change frequency, oil grade, faulty selenoids, not enough warm-up time, desingn flaw?

Are the parts that are returned for reinstalllation "improved" or just new?

Are we talking potentially bent valves and the need to pull heads here??!!

Thanks.
 
#11 ·
Amending my post above.

The variator and solenoid will be a new part, the cam bearing cap will be sent to MNA to be machined and sent back to be put back on the motor.

Usually it is a misfire code, then we have to check the electronic timing values to make sure they are within spec.

There is no clear indication as to why this occurs. I have seen cars come in that barely exhibit the "chatter" , and I have seen them where there is a clear audible misfire in conjunction with the chatter. I have also seen cars that the client states there is a chatter, but when it gets here.....nothing. We keep the car for a couple days to perform cold starts and have a video recorder on it every time we start it. It may be three or four days before we can get the car to do it.

If your car does this intermittently, I recommend recording your cold starts to catch it in the act. This will save a great deal of down time with your dealer.
 
#12 ·
How many of the cams are we talking about here? Are two affected or all four?

I've heard reference to a twenty hour job on the forum. Is that if you need to pull the heads for valve damage or is this just speaking to peulling the valve covers and making the updates to the variators and solenoids?

Thanks.
 
#14 ·
So that's 16 actual or 16 book hours? Do you have a procedure that you can post for us? I'd love to look it over and know upfront if this is something that I could handle.

For example, does it involve pulling anything other the the valve covers and timing system apart and then removing the cams? Does the washer system need to come out to get access?

Thanks.
 
#16 ·
Awesome. Thanks. I appreciate it!

I assume one could do all the assembly/disassembly loabor and send out the cams, right? Also, why is their machining needed for the cam caps? I guess I just don't understand the design on this system so the photos and procesure will be very enlightening.
 
#19 ·
When doing this work are there improvements performed/parts replaced that will stop this common problem from happening again? If a vehicle has had this work done, I would assume its one more thing under the cars belt to not go wrong again...
 
#21 ·
Hi All,

I'm a noobie on this forum and considering seriously a purchase of a QP as my first ever modern italian exotic. I'm working my way through this forum to see what goes wrong on the QP and how to remedy the problems.

Can any one advise as to this Variator / Machining Cap issue.

Regards JP
 
#24 ·
The cam caps have to be sent to Maserati North America even after the vehicle warranty expires. There are only two machine shops in North America that modify them.
The variators can be purchased at any Maserati Dealership.

To say this is an easy 16 hour job is not a very smart statement. In my judgement it's about double that.
 
#26 ·
CHALLENGEHAULER and FIXED_1_ONCE have provided good technical information on this post.

It is a known issue, that I believe could affect all 4.2L engines (intake cams) so far as I'm aware but for some reason seems to be much more prevalent in the QP from what we've seen and heard.

In regards to the CAM Position Sensor, I believe that a good mechanic can perform the work. However, if the problem is the CAM Variator, then I agree that a true dealer should perform the work. They will have access to the latest information on the problem and on a solution that seems to work best.

In any case, I would only send the parts to be machined through Maserati North America. They know how this needs to be completed.

I have not heard of any cars that were properly repaired that have seen the problem since the repair. Honestly this is one that I believe Maserati has been figuring out along the way but I could be wrong.

Also, it doesn't seem to be the case that all cars suffer from the problem and require repair. Truly, factory techs at the Maserati Dealers will know the most about the problem as they see the largest # of these repairs.

Best Regards,
-- Jeff
 
#27 ·
Also, this type of sound from the engine compartment doesn't necessarily indicate that it's the variator. Other, simpler, things could be at play, but it's best to be sure. Rather than guess and potentially allow larger problems to accumulate, have a qualified mechanic investigate.
 
#28 ·
I just test drove 2007 QP Auto with 29k miles and I noticed some vibration in the steering wheel when driving 25-35+/- mpg, I thought it was bad tire balancing, bad tire ware or a bent wheel. When I parked the car and put it in neutral I started to slowly rev up the engine and I noticed that the engine would start to vibrate and you could feel it in the steering wheel at around 2-3k+/- RPM. Felt like bad timing.

What do you guys think that is, could that be a symptom of bad variator or something else.

Thanks
 
#29 ·
Best way I have been able to determine how to tell based on posts: Start it from cold. Since the auto is a wet sump, the hydraulic lifters should almost immediately fill and you MAY hear a second of a sound that is "similar" to marbles in your engine somewhere (valves tapping etc). If it continues sounding like marbles for a 30+ seconds, then we have an issue.

Duoselect/dry sump cars will hear the sound for 3-4 seconds at most, but it will be much more obvious.

Transition for VVT takes place over 4000, so 2-3k doesn't seem likely to be related to this. Probably just needs a computer reboot (seriously) to get it to work a bit better. Unplug the battery overnight and try again the next day. You would need the code to unlock the radio.

Make sure you run through the proper startup procedure. Turn the car on but do not run the motor, let it sit for 1 minute, then start the car and let it sit for one minute while doing nothing. This will have the car figure out the valves, throttle body etc. Only has to be done when you pull the power as per the service manual.


If that isn't it, probably spark plugs, though I doubt it at 29k miles. Well it COULD be, though it is more likely that if you drive it REAL hard for a few minutes it will resolve itself, after trying the above. These engines don't like to be driven lazily all the time,
 
#30 ·
I will do more in depth check when it arrives in about 1 week or so. Ill check the timing, plugs and maybe reboot the ECU.

I did start the car on cold but did not really hear anything maybe because I was not listening for it. The car was all warmed up when I drove it when I was feeling the vibration in the steering wheel while driving at around 25-35 mpg and when I had it parked and was revving it near 2-3-4k RPM.

Any one has any other feedback what could be causing the vibration?
Thanks
 
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