March 4, 2021

PROJECT LOG: #PoisonIvy [3-28-16] New Head, New Problems

So, I got the head back. It was beautiful. It was cleaned, resurfaced, and had a valve job. I picked up a new head gasket from the parts store and then proceeded to bolt the new head onto the engine with the ARP headstuds. Once it was torqued on, I began putting together the rest of the valvetrain; lifters, rockers, and cams.

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One by one, I kept bolting everything and connecting everything back together. Until the first new problem introduced itself. The oil filter was extremely tight and I could not remove it. So, I decided to swap the entire OFH (oil filter housing) all together. I went inside and robbed the OFH off of my spare 6 bolt short block.

Finally, I was ready to start the car. But first, I wanted to prime the oil system to ensure there was plenty of oil in the head and turbo before the car was to be fired up. I cranked and cranked and decided I was ready to start the car. I decided to check for leaks first, which proved to be a very wise decision. There was tons of oil under the car.


The fitting for my aftermarket oil pressure gauge had to be removed from my old OFH and installed in the new OFH. The new OFH must have been cracked inside where I installed it and it blew apart while cranking the car.

So, the new day, I removed the OFH and installed my 1990 DSM, externally cooled, air cooled OFH. I didn’t have a cooler for it, but a buddy did and he lent me his. So now the 90 OFH is installed and ready to fire up. The first start was a bit rough as I also installed my new PCE 1000cc fuel injectors during the head replacement. But after a few minutes, I got the dialed in pretty good and the engine ran great.



The next day, I drove down to see my friend, Kurt. It was an hour and a half drive and it was a very warm day. The car ran really hot and once I got down there, I decided to check my thermostat. It was stuck open, so I removed it completely and the car ran a lot cooler afterwards.


On the way home, the car was running great. Pulled hard, ran smooth, it was awesome. But that eventually diminished as well when I heard a loud humming/grinding noise coming from the drivetrain. I was about to pull over thinking something was about to fall off the car when suddenly, the noise disappeared.

Several miles later, I did a 3rd gear pull. I thought I had broken an axle as the car swerved around from right to left. A little while later, I did a 3rd gear pull. This time there was no swerving around, but it slipped under boost, just like would happen when trying to do a pull with a broken axle.

The next morning I jacked up the car and inspected the axles. All four looked fine. So I decided to remove the boots on each front axle CV joint. Everything still checked out fine. So, this means either my transfer case, viscous coupler, or center differential is bad. It has been cold and snowing out ever since so I haven’t pulled anything else apart yet. I am really hoping the center differential isn’t bad. I really don’t want to pull the engine/transmission already.