I have a very prominent customer who has not received gains on his Subie and I need some help.

As he is located in Idaho, and we have no one near to serve him, if any of you guys are familiar with this engine, I could use some help at where to direct him to look.

Got anything for me?

Ron

Check your e-mail Ron...

Karl Fortner
Tacoma, Wa.

Check your Email, Ron! TracyG

hi Ron, the other day when I did some searching online for Subaru info, I saw in several places repeated mention of the tendency of the Subaru 2.5 non turbo injected engines from I think it was 96-up to blow head gaskets. Very well known trend w/ those. The factory had Dealerships add stop-leak to the coolant as a Service Campaign... . Anyhow I hope our freind in Idaho isn't experiencing that. Some leaked external, some internal(worse way to go). I saw it mentioned that by 100K miles up to 90% of the 2.5 non-turbo ones would have a head gasket fail. Hope it's not true in this case, thought you ought to know of this...TracyG Gadgetman Reno

I drive this generation of Subarus and have a 1996 and 1997. Head problems are catastrophic when it happens with pressurized coolant systems and stopped engines.

In my experience, they get about 8 to 9% gains. Make sure you understand where the PCV connection is and plug it. Also check the many vacuum lines for leaks. Other than that, I haven't found anything special other than the unique and cool horizontally opposed piston design. I will post any new finds. In the next couple of months I plan to rebuild a 2.5 and 3.0 Subaru engine which will give me an opportunity to study the intake dynamics etc.

So, a nice 4 hour/300 mile trip out to Spokane, Washington to meet Aaron and his
Subaru.

This is Aaron





Checked all the pertinent hoses etc for leaks, nothing relavent to be found. Pulled the TB off, it gave me an opportunity to check the groove and to see what else was hiding underneath.

The first red flag that went up was when I was checking the ecu readings... the TP was at 0.0

Question 1.... If the TP is at zero on a cabled TB how is it idling... further checks... found the IAC hiding off to the left of the TB.



It has that 3/4" hose connected to it and the opening inside the manifold is just as large. Solution, had a pre-made plug with a 1/8" hole drilled through it... stuffed that into the hose.

Then put everything back together.

Cold ecu readings...
Load_PCT 5.1
SHRTFT1 -8.6/-12.5
LONGFT1 2.3
MAP 7.4
RPM 950

Engine at 190F

Load_PCT 2.7
SHRTFT1 -.8/-2.3
LONGFT1 -7.8
MAP 7.4
RPM 700

Engine after plugging the IAC inlet @190F
Load_PCT 2.7
SHRTFT1 -8.6/-12.3
LONGFT1 0.0
RPM 675


@2000rpm
Load_PCT 5.9
SHRTFT1 4.7/5.5
LONGFT1 1.6
MAP 6.2

The engine has 155,747 miles on it, sounded a little clunky when he moved it cold.

Took it out for a spin after the IAC fix and even at that mileage its got some spunk.

Aaron will reset the ecu tonight and start monitoring his mileage tomorrow.

I expect the trims to change a bit but with the drastic change that occured just by minimizing the IAC airway it should be good.

Grooving right along...

Karl Fortner
Tacoma, Washington