Subaru STi Engine Project Part 1, Introduction
One of the first jobs we had after we opened our doors in 2005 was also one of the toughest, most involved jobs we’ve had to date. After flogging the hell out of his 2004 Subaru STi for most of the season, a fellow track mate and good friend discovered engine oil and coolant were intermingling, most likely caused be a leaking head gasket. The symptoms got worse towards the end of the season and he decided that the cause had to be diagnosed before the next track year (which runs from around April to November in Michigan).
We sat down with him and put a plan together. Since the STi has a flat or “boxer” style engine, the heads are actually on the sides of the engine, right up against the inner wheel wells on the little Subaru. This location necessitates the removal of the entire engine in order to get to the heads. While the engine was out, we decided to do some major clean-up work as well as a very meticulous re-assembly. We wanted to make certain the problem was fixed and the engine was assembled with the utmost care and attention to detail-- better than any assembly line worker at Fuji Heavy Industries ever would have. Jason, the owner, also wanted to do a mild power upgrade with a new Vishnu supplied downpipe, exhaust and requisite ECU reflash. The downpipe is much easier to install when the engine is out, so we tackled that before re-installing the engine to the car.
As you can imagine this is a pretty involved process, and I will not go into all the details here, but I will give you an “executive summary” along with photos. I will continually update this project blog as I have time, so keep checking back. I also hope that Jason will chime in with comments along the way, to give you a customer’s perspective on the work that was done. I can tell you that the car ran all season this year on the track and as a daily ride without any hitch from the engine (but the suspension-- well that’s another story!).