Upgrading to 911 Turbo
Valve Covers
(and stopping those leaks!)

Difficulty Level 2

Difficulty scale:
Adding air to your tires is level one
Rebuilding a 911 Motor is level ten

Figure 1:
Magnesium Valve Covers

Figure 2:
Magnesium Valve Covers (underside)

Figure 3:
Upper Turbo Aluminum Valve Covers

Figure 4:
Lower Turbo Valve Cover

Figure 5:
Lower Turbo Valve Cover

Figure 6:
Machined Edge of Lower Turbo Valve Cover

Figure 7:
Machined Lower Turbo Valve Cover

Figure 8:
Valve Cover Gaskets

Figure 9:
Valve Cover Gasket Kit

     To see if your car is suffering from valve cover leaks, take a look under the car and check the bottom of both the left and right valve covers.  If there are oil drips there, as well as oil on your heat exchangers, there is a good chance that your covers are leaking.   Check the ones on top too, from within the engine compartment.  These are also very prone to leaking.  A good way to check for leaks is to clean the entire engine.   You can clean the bottom of the engine by taking it to a self-serve car wash that has a degreaser setting on the nozzle.  Don't spray any water inside the engine compartment, as there are many things in there that you just don't want to get wet.   Instead, use some degreaser on a rag to wipe out the inside of your engine compartment.  Please don't dump any degreaser on your driveway, as this pollutes the environment.

     If you suspect that your valve covers are leaking, then simply remove them off of the engine and check to see if they are warped.  Figure 1 and Figure 2 show both the front and backside of the standard, early magnesium valve covers.   If you place these on a flat surface, you can check to see if they are warped or not.  Even if they don't appear to be warped, remember that they will deform when they are heated by the motor.  If the valve covers are warped, then you should definitely replace them.

     The standard upgrade is to replace the valve covers with late 911 Turbo valve covers.  This is a bolt-on replacement for 911 owners.  Make sure that you empty the motor of oil before you remove the valve covers, as there is a good chance that you will have a major oil spill if you don't.  The Turbo valve covers are made of aluminum, and will expand at the same rate as the cam towers, decreasing the amount of warpage.  The upper valve cover, shown installed in Figure 3, looks very similar to the original magnesium one, except for the fact that it is unpainted.  The lower valve cover, shown both in Figure 4 and Figure 5 has fins to improve cooling and also increase stiffness.

     If you own a 914-6 or are performing a 914-6 conversion, you need to machine down a section of the valve covers in order to have them clear the rear trailing arms.  If you don't do this, then you will not be able to remove the covers without either removing the studs from the cam towers, or dropping the engine.   Figure 6 and Figure 7 show the area of the lower covers that must be machined off in order to make the valve covers fit.  This needs to be done to both sides.  The fins must be machined down about a quarter of an inch in order to accommodate the rear trailing arms of the 914.  Machining the covers will not hurt them, and they will still function very well.

     When you install the Turbo valve covers, make sure that you use a new set of valve cover gaskets, screws and washers.  Figure 8 shows the valve cover gaskets, and Figure 9 shows the complete kit with all the nuts, washers and gaskets.  It is important not to overtorque the nuts on the valve covers.   I was not able to locate a torque specification in the factory manuals, but I would not torque them greater than 8 ft-lbs.  Make sure that you torque them down in a diagonal pattern, and it is advised to start at 4 ft-lbs, and then after all of them are tight, re-torque to 8 ft-lbs.

     Well, that's about it.  It's a really easy upgrade that should stop one of the most annoying leaks on 911s.  No more smoke coming out of the rear of the car as the heat exchangers burn off excess oil!  Pelican Parts carries the 911 Turbo valve covers, and the valve gasket kits at competitive prices, as seen in our 911 on-line catalog.   Please remember that your continued support and purchases directly impact the development and expansion of this site.  Please help to keep the site growing by letting us earn your business.