damage from malfunctioning AVCS?
 

My forged 08 sti engine had its post 1K oil service yesterday, and the local garage overfilled it, to the point of it smoking(quite a lot) after being parked, it also caused an p0024 exhaust AVCS mil to come on.

I had the excess oil drained out, but when i logged the car the exhaust AVCS is acting really weird, the left bank will do nothing and then jump to 45 while the right seems to respond normally.

I spoke to the garage who built the engine, and im taking it in on monday, but i was wondering if its all right to drive it there. Does the oil feed to the left AVCS exhaust solenoid feed anything else, as in if there gunk in the filter is something downstream of the AVCS valve being starved of oil?

Ive tried an ECU reset, and tried a reset and loading it before the fuel pump duty drops.

Cheers for any advice.

The exhaust avc's are supplied through drillings in the head, which also feed the cam journals, there is no pipe feed like the inlets with a small filter in the banjo bolt, so basically you must be getting an oil feed to the ex avc's otherwise the cam would of siezed by now.

Usual problem if an engines been stripped is the avc's pulley or solonoid sticking, did the engine before its rebuild have big end failure ?

No it had a ring land, it was rebuilt over xmas, forged rods and pistons etc.

Its done about 1200 miles since the rebuild though, and it wasnt doing this before, its literally since the overfill yesterday.

Ive only done 50 miles since the mil came on, would the cam journals survive that long with an intermittent supply? mind you i dont know why an overfill would cause the supply to the head to be blocked?

Cars only done 30K, seems cursed, although it got 321T and a decat when it was being forged, so for the short period its been working, it was quick.

cheers for the help.

You won't be using that garage for servicing any more, will you!:nono:
That must have been a big overfill?

JohnD

No, i was gonna do the 1K change myself, as i couldnt get to the scooby garage, but the cold, was so cold, and it turns out now in my 33rd year im not the man i used to be!

And theyre only at the end of the road,

Guys alright actually, accidents happen, and i blame the car, its evil.

It feeds the cams first, before the solonoid, you must have oil feed to the avc's as you have movement recorded.
I would say the overfill has nothing to do with the avc's problem, as i stated before they do suffer from sticking when they have been apart, i would swop the avc's solonoids over & see if it does the same on the other bank, if it does you know its the solonoid, if not it could well be the pulley itself sticking, sometimes a tap with a rubber hammer does it.

I guess i should be alright driving it(gently) to the garage then.

Are the exhaust solenoids on the oposite side to the inlet then? I wondered if the guy changing the oil could have damaged the plug when undoing the sump plug? Is the cam sensor down there, i suppose if thats off at all the avcs must go a bit ape.

The exhaust solonoids are underneath the engine at the front corners, they also have there own earth strap to chassis, they could of been disturbed when the undertray was removed to change the oil & filter.

I swapped the solenoids yesterday, and the symtoms seemed to switch sides, so i got a new one and stuck it in, but they still dont respond exactly the same, does anyone know what the tolerance on the difference should be? its always the left side which is delayed, if you blip it from idle, its slower and doesn't advance as much, and then if you hold a steady, say 3k and blip it the left doesn't advance from where it was holding but the right does. Im beginning to think it might be some sort of oil supply problem, thats assuming there is a problem at all, i assume that they run in series in the oil supply, so i guess one will have a slightly lower operating pressure than the other, which would make it slower.

Doesnt seem to be alot written about exhaust AVCS system.

I did some logging earlier to show the issue,

Attachment 56449
Attachment 56450

In both the dark blue and the light green are the exhaust cam position, the yellow is load, and the purple and blue close together are the inlet cams to show how close they are.

The jumpy nature of the exhaust ones sorta implies to me that the left is jamming or mechanically jerky and unresponsive, they are much better than before, but i assume they are supposed to be more like the inlet. Dunno what to do next really, perhaps take of the left pulley and clean it, can you do that without taking the head off?

Can anyone confirm if im a total spaz, which side of the engine do subaru call the left, is it the left from the drivers perspective, or from in front?

The R/H is the turbo side, pulley's can be removed without removing the heads / cam covers.

I got the AVCS sorted in the end, although i swapped out the good OCV for another good OCV which threw me for a while! all good now though. Cheers for all the help.