My 458 with 148,000 miles developed a new rattle at start up Im suspicious that this might be due to oil starvation of the cam variator system There was a common problem with the Maserati cam variator oil check valve and end cap design which affected many cars. The 458 has a different design which is much more robust. Anyone know about the 458 cam variator design ? Does it rely on a check valve and or solonoid to keep the variator activated on start-up And do the oil pressure sensors located in the intake valve covers participate in their operation?
The 458 design is the same as the old Maserati design. There are two check valves P/N #200458 in each head, which prevent oil drain-back on engine shut-off. The Ferrari engineering diagram for the variator solenoids also shows an internal check valve, but I think that this may be a mistake and they are showing the external check valve in the head being incorporated the the solenoid. The check valves are located under the cam cover/upper cam bearing cap casting, which requires special tooling to remove. I suppose you could have a problem with a solenoid, and they are easy to replace. You might also have a worn variator. Have you tried listening to the noise with a mechanic's stethescope?
A Big Thank You! What made me think about Cam Variator failure was that the problems began as I was accelerating up near the redline but in a gradual way. I got a cut off and an ENGINE CONTROL SYSTEM FAILURE warning So I immediately let off the throttle. The engine was running rough and there was a rattling which was new and obviously new and abnormal Then I got a HOT CAT TEMP warning light for a few seconds and then The Engine Control System Failure light warning I limped back home at less than 3K RPM I WAS LESS THAT 1/8 TH OF A MILE I’m thinking that the Variator failed and that rich UN-ignited combustion gas passed into the exhaust valve and then upon reaching the cats ignited causing a thermal spike. So I’m hoping that changing the 4 Variators and their 2 solenoids and check valves will do the trick. Of course why not change the timing chains and chain guides and tensioners as well. Thank you to a seasoned Master Tech MOTOB
During the work up eval we decided to do compression testing and leak down.My engine passed the factory specs of 155 +/-5 and less than 10% leak. But dealer had never dealt with this kind of high milage Dealer has done all the service work and oil was changed faithfully and so were many preventative service items and repairs Dealer has never dealt with my kind of daily driven 458 I have some knowledge of Maseratis as i saw many with variator issues during my ownership of the Ferrari 360 and California . Maserati service was conducted at the same center and I asked about the repair record. They told me that they were having a high rate of problems with their variators.
There should be fault codes stored in the engine management ecu's related to the engine running rough and the engine control system warning. If the variators are at fault, there should be a timing related fault stored. Has the dealership downloaded all of the faults?
I asked about this and was told that they didn’t see codes to alert about timing issues Perhaps my Cats need replacement . They passed the SMOG about a year ago (4,000 miles ). Maybe it’s a slightly loose timing chain due to failing tensioner or guides that are cracked or disintegrating along with a failing. Tensioner or 4 There is also a front radiator coolant leak which is new —car had engine out service for valve cover gasket replacement and oil pump o-ring gasket just less than 400 miles ago. No problems with over heating or engine noises or any codes. Passed test drive
I don't know where you are on this issue, but there seems to be a problem with your vehicle's timing system. This could be a problem with the variator, chain or solenoid valves. However, if you hear a rattling sound while the engine is running, the problem is most likely related to one or more of your variators, which is normal considering that your car has covered approximately 250 thousand km. I had a similar problem with my 599 GTB (even though it had only 7,000 miles on it). I was getting a check engine light warning without any problems with the car's traction and operation, and I fixed the problem by changing the solenoid valves. Replacing a variator is a laborious job that requires long and meticulous workmanship. It would also be a good idea to replace the chain and solenoid valves when replacing your variator, but this is not a rocket science. You can solve this problem with the help of a good and experienced mechanic or service, but unfortunately this is a costly job. Have a nice day. Good luck.
