VarioCam Solenoid/Actuator

[boxslrr]

1998 Boxster with Tiptronic transmission, 80,000 miles on the chassis but only a few thousand on the rebuilt engine. Having pulled the engine and preventively installed the LN bearing, I noticed a problem with the VarioCam assembly. There is not much written on this so I'm seeking input from others. It appears that vibrations have caused the unit (right bank, flywheel side). to loosen and even bolts to back themselves out.

- The small oval/diamond ring around the solenoid lost a bolt
- The solenoid itself has loosened and backed out, protruding from the camshaft cover plate
- The small brass plate bolting the solenoid to the actuator has cracked, allowing it to slip out
- One of the three long bolts mating the actuator to the cylinder head has backed itself out and will not grip the threads

The actuator looks to be in good condition with no damage.

The solenoid assembly is a different question. The spring and pin were still found in place inside the actuator. I tried testing the solenoid by applying voltage however there was no mechanical action as solenoids usually exhibit. It did seem to warm up. How can it be tested to see if it needs to be replaced?

Also, side question: what it's the part number for the exhaust camshaft adjustment plate? I can't seem to find it.

[shadrach74]

Originally Posted by boxslrr

1998 Boxster with Tiptronic transmission, 80,000 miles on the chassis but only a few thousand on the rebuilt engine. Having pulled the engine and preventively installed the LN bearing, I noticed a problem with the VarioCam assembly. There is not much written on this so I'm seeking input from others. It appears that vibrations have caused the unit (right bank, flywheel side). to loosen and even bolts to back themselves out.

- The small oval/diamond ring around the solenoid lost a bolt
- The solenoid itself has loosened and backed out, protruding from the camshaft cover plate
- The small brass plate bolting the solenoid to the actuator has cracked, allowing it to slip out
- One of the three long bolts mating the actuator to the cylinder head has backed itself out and will not grip the threads

The actuator looks to be in good condition with no damage.

The solenoid assembly is a different question. The spring and pin were still found in place inside the actuator. I tried testing the solenoid by applying voltage however there was no mechanical action as solenoids usually exhibit. It did seem to warm up. How can it be tested to see if it needs to be replaced?

Also, side question: what it's the part number for the exhaust camshaft adjustment plate? I can't seem to find it.

Did you do the build? If you have a bolt that has backed out and is stripped, I'd bet that was due to installation and not vibration... I'd be calling the builder.

[BYprodriver]

Sounds like whoever installed these parts did not torque them properly. (7.5 ft/lbs)

You may have noticed it's no fun accessing these parts, so I would replace the solenoid, damaged fasteners, solenoid seal, cam chain wear pads on the actuator & exhaust cam drive gear. The cam gear may be superseded to a new improved part & number. The cam gear to exhaust cam bolts are 10.9 grade & require 10 ft/lbs + blue loctite.

[woodsman]

did the bolts have loc-tite on them?????