The GT Goes Under the Knife
Regular readers of my column know that my 1991 928 GT has a supercharger and an intercooler. This past summer, the intercooler decided to spring a leak and dashed my summer driving plans. Since the car was due for a timing belt, water pump, and maitenance, I decided it would be easier to just pull the motor and tear into it. This will be the first of a number of articles documenting the steps I am taking to fix and refresh the engine. By no means is pulling the engine part of 928 ownership. I just happen to be a bit crazier than most.
Because I have a mid-rise lift, I decided to try dropping the engine through the engine bay, instead of lifting it up and out. I primarily did this because the headers are a pain in the butt to take off and I thought it might be easier to leave them on. In hindsight, it was about the same amount of work. However, because I had to drop the steering rack, I was able to see some issues there that I might not have seen otherwise, so I’m glad I went this route.
The first step in taking any 928 engine out is to drain the fluids and pull the radiator. It gives you a few extra inches of clearance and allows you to clean up all the dead bugs and leaves that are stuck in it. Just be careful if you have an original 20+ year old radiator. The end tanks (particularly the passenger side) have a tendency to spring leaks. They are replaceable, but it’s not an easy task – and usually not a DIY one at that. 928 radiators are VERY expensive, but there are some new aftermarket options that fit perfectly for less money if you’re okay with a non-OEM item in your 928.
Then I used a couple 4×4’s to suspend the engine in the bay while I removed the steering rack and cross member. If you ever need to re-do your oil pan gasket, this is the tool to use. You can easily make one of these setups for about $20. I cut a 4×4 to fit the width of the engine bay and then added a couple 2×4 “feet” to raise it up just a bit. Then using two big eyebolts, some chain, and a couple master links, I hooked it up to the lift points on the engine. With the eyebolts going through the 4×4, I tightened the nuts on the eyebolts until the engine started to come up a bit. At this point I dropped the rack and cross member.
I noticed a hose that connects one end of the rack to the other end was crushed. I believe this line is supposed to help equalize pressures. Every now and then, my rack would feel like I lost power assist. I wonder if this was the cause? I also noticed both boots on the rack were torn and in need of replacing.
There were obviously a number of other items that were taken apart like the clutch, front sway bar, lower control arms, fuel likes, etc., but once everything was out of the way, I placed a moving dolly under the car, lowered it all the way, and then slowly loosened the eyebolts on the 4×4’s until the engine was resting on the dolly. Once it was resting on the dolly, I made sure everything was clear and lifted the body up, leaving the engine on the ground. It went so smoothly, that I was able to do it solo.
In my next article, I will be documenting disassembly of the engine, heads, pistons, etc. I am also going to re-ring the motor, which requires reconditioning the alusil block. There is a special procedure required to do this.
Mar your calendar; on March 29, 2014 we will be having a 928 Tech Session. We will show you how to service the 928 transmission and final drive unit. We will also have a 928 engine you can help take apart and get familiar with. If you are interested, send me an email at firstname.lastname@example.org or call me at 734-837-7908. Also, if you are interested in hanging out with the 928 group, we get together at the Parrot Cove Yacht Club in Troy, MI on the second Wednesday of each month from 7 to 9:30. Come and join us.