Thought I'd introduce myself after lurking here for months picking up so much great advice from your fantastic resource. Thanks so much. Bought my old wrx gc8 2000 last year. Best decision ever - my perspective, not my wife’s...

After years of doing my own work on beat up old bangers that were worthless and went like c*** and being reasonably handy with a wrench, I figured why not get a wrx as a second car to 'learn' EJ motors? (will DIY service my 04 Outback now too).
Seems to be a clean stock Aus model apart from GD front suspension and wheels and an aftermarket exhaust. Few dings and scratches but I didn't want a car I can't park down the shops, I wanted a car that made me grin around corners and leaving the lights in the wet (finally I like Perth winters!). No plans to modify further, just want to keep it running sweetly. 260k on the clock (!) but drives better than public roads and my limited driving ability allow. EJ20 motor and engine bay seem stock and well cared for. Timing belt age was uncertain but certainly not 160k old and that's a job I fancy doing myself anyway. Figure worst case I'll be dropping in a used donk which might be easier than doing a belt and water pump in the car anyway.

Done new pads and rotors, all the fluid changes, upper engine cleaner, fuel treatment, air and fuel filter, new radiator, plugs and leads. Stripped down and cleaned the noisy p/s pump (cured). Only had 98 fuel in it since I got it, previous owner advised he’d run it on that too. Had boost die early on and thought the turbo must have carked silently, but it was the wastegate circlip gone walkabout (simplest fix ever barring getting the sodding heat shield off!).
So to my current problem: a few months later had some stuttering on boost and it suddenly dawned on me that the CEL bulb had blown (it was missing!), replaced and found knock sensor and O2 codes . After new OEM O2 and knock sensors it’s a very little bit juddery around 2500-3000 rpm when cold (feels like something is cycling) and has had a new OEM MAF sensor just to be sure (no change). Idles too high? (900) after removing and cleaning the throttle body and IACV, neither of which were too bad, I'm fairly sure it was at 700 before that. I’m assuming the tacho is accurate.
Replaced the easy to get to vac lines and sprayed lighter fluid everywhere I can get to without showing up a leak. Reset IACV several times. Fuel pressure is OK (43 psi) and the FPR seems to behave, though I guess the pump could be on the way out, I only measured the pressure with the car stationary. Compressions are marginal, but consistent with an aged engine?: 170, 155, 163, 170 psi (cold, can’t see how you’d do them hot without getting 3rd degree burns). Vacuum testing showed a pretty stable vacuum – too good if anything, snapped to zero on opening throttle then drops back past idle level and slowly returns. So I think I've ruled everything out except: the IACV (though it obviously mostly works), leaks hidden under the manifold, dirty (yellow) injectors and engine damage. I finally found the ECU and it’s a stock green one – the plugs in are blue, grey and black. Will get the inlet off and get the injectors cleaned and renew the awkward hoses and check the stock intake to the turbo, but I can't really see the point in doing much more investigation, if it's a bearing or valves or a gasket I reckon I may as well either play lotto with a used engine, or bite the bullet and get a long block. I like the idea of stripping down the engine and rebuilding it but it just doesn't seem like a worthwhile proposition unless you’ve got a workshop and can get the work done for free.

Oil: running Castrol Edge 0W-40 after reading Bob-Is-The-Oil-Guy's thread, swapped from Nulon 5W-30 fully syn after the last oil change (car had Nulon 10-40 semisyn in when I got it). Logic was most of my kms are short journeys so I figured the low winter rating would help while warming up (esp over winter) and the 40 hot would be plenty for the sort of driving I do (no sustained high rpm). I do next to no kms and will be doing regular oil changes every 6 months. But reckon I’ll go back to 10W-40 at the next oil change and see what it feels like. I know some would say I’ll be stuffing the journals, and others would say with a stock set-up it doesn’t matter as long as it’s oil. Nothings getting any worse - yet…


Bloody hell, that was WAAAY too long sorry. Be interested in views if anyone is still awake and can be bothered dealing (gently!) with a newb with no tuning aspirations. And I’d be interested in buying a known good IACV for a 00 GC8 if anyone has one they don’t need. And probably a used engine in a few more months

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