Only recently started the engine (ej20t), was rebuilt over a year ago.
It doesn't run too badly, although blows a fair bit of smoke and keeps revving really high (ECU keeps coming up IDLE VALVE problem, but doubly checked the wiring today and its ok. Even if I totally block of the supply to the idle valve the engine runs).

Anyway, I was getting a bit worried yesterday with the smoke, but I knew there was oil in the exhaust from the mandrel bends etc. But ran it for a minute just now, and then saw this, black oil leaking out one of the exhaust manifold gaskets... I don't think this is a good sign.

So yeah, anyone know what it could be, valves? rings? headgasket? I did a compression test yesterday when I started to panic, and all 4 cyls came out great (11-11.5 BAR).

How long have you run it? Run it for 10min to burn out any oil and then it should be ok. It's obviously had a bit of oil inside the combustion chamber and it's being burnt off and making any exhaust leaks really obvious.

I've probably run it for about 10mins but no more than a min each go, so lots of short bursts.

Just run it again and got it up to operating temp, still a bit of smoke coming out exhaust but doesnt seem to be oozing out the flange anymore. Only thing is i just can't get it to idle at normal revs... with the idle valve blocked it will go about 1000rpm, but with it all normal, it cycles between 2,000 and 1000rpm, checked for leaks around all the inlet manifold gaskets but everything seems normal.

Just uploaded a video. You can hear the engine rev up and down, but no one is touching the throttle.

make sure there is no cracks in the casing of the heads!

Shouldn't be, they were all stripped, machined, cleaned, pressure tested etc at the engine shop. I'll have a look though

Check your plugs and their gaps, also check for air leaks. Hard to tell from the vid but it sounds a little hunting. Any vacuum lines off ?

did you have the motor upside down at all? I recently tipped my over to change the sump and forgot to pull the FULL oil filter off first. Werl, oil went everywhere inside the intake and all. Cleaned it out, pull the plugs and turned it over to make sure it didn't go hydraulic and ran it. For the first 20 min or so there was a lot of smoke and the open exhaust (no cat/muffler) sprayed oil all over the place, but then it settled down and was fine. Could be a similar thing happening for you.

Yeah I assembled part of it upside down, but it had no remnants of oil in it as all the parts were cleaned before assembling.

Yeah it was sorta hunting, it was the ecu turning the idle valve on and off, if its electrically disconnected it stays at the lower rev (still higher than 1000rpm).

I hooked up a vacuum gauge this arvo, got great results, its getting good steady vacuum at idle, drops to near 0 when opening the throttle then spikes when snapping it shut. I got it to idle good too, I blocked off the air pipe to the the idle valve and then adjusted the bypass screw at the throttle body to get it to sit about 750rpm, was purring nicely for 15 mins.. AND NO SMOKE! Fans come on and off. Then out of nowhere after 15mins it started smoking again, and got pretty bad, engine still running fine though. Hooked up the vacuum gauge again, and was still reading great results...
Its got me stuffed.

stop wasting time, just get it finished and drive the thing,I told you not o buy a vacuum gauge

Bah, who said i bought one

I'm going to take the cylinder head off and do a full inspection tomorrow.... Nah, just kidding.

Yes you are right, I said i'd put the sidepods on at the weekend, and ended up playing with the engine, should get the rear bar from the powdercoaters tomorrow too, so i'll try and bury this problem and move on.

I have seen this before . The cables to the AFM were damaged & the isolated wire was getting a feed to step the motor up in rpm . I pulled the dip stick out and there was nearly 2ltrs of fuel in the sump . This washed the bore & fuel was coming out the zorst.

the other this was the kid down the road lined the ring gaps all up , I striped the motor down set the rings correctly & its now fine

Thanks Neil, i'll check out the AFM wires.

Yeah, its been that long ago, i remember lining all the ring gaps to the angles in the manual, but maybe something like that has happened. I'm not going to worry about it for now, i might take it to my parents place on the weekend and take it for a fang around their makeshift rally track (driveway), as I havn't put any load on it yet.

did you fit the pistions in the correct order IE: A pistion in the A cyl B pistion in the B cyl

& the marker > pointing the correct way on the pistion ?

were are the crank breathers plumbed to ?

what sump have you fitted to this ?

not related to the oil leak , make sure you have at least two 8mm earth straps to good earthing points .

Yeah all pistons went back into their original holes. the arrow was in the right spot.

Crank breathers are plumbed just after the air flow meter.

I have the bugat5speed sump

And yeah, got a thick earth to the gearbox and the one to the inlet manifold.

Mark, yeah you can normally get away without the 2nd one, but you are relying on the electrical connection between the gearbox-adaptor, adaptor to crankcase, then crankcase to inlet manifold for the grounding of sensors and other bits relying on a good engine ground. So its always a good idea to have it.

You can buy earthing kits (or make one up) that have a lot more than two earths. People swear they give better smoother running engines. Look on the subaru forums, there are probably some FAQ type DIY guides about the best places to earth.

Yeah, but beware, a lot of them are complete rip off's. I've seen them for $150, and all it consists of is a few legths of cable with lugs on either end. I could makeup similar cables myself for about $5 in cable and lugs.

I had all sorts of issues with my starter not wanting to turn when the car was hot. I also had the odd weird code off the motor for no good reason. A mate was telling me about the loss of conductivity that metal suffers as it gets hot. In the end, I ran a 10mm battery cable off one of the starter bolts back to the main earth point in the rear floor and also to the -ve battery terminal. The car now starts now matter how hot it is and the starter is a STOCK 1800 manual starter. Keeping in mind, my battery is now in the front passenger footwell too and theirs over 2.5m of cable running to and from the starter. There is no substitute for a BIG FAT earth cable.

Thanks for the information guys. I will make some changes. Cheers.

Ok, well, I ended up taking it to my parents place so I could give it a bit of a run. It ran well, goes hard even though i didnt even take it past 3500rpm. I also can't beleive how good it sounds, and its not loud at all... I think I'll be under 96dB.

But, it is still blowing smoke, didnt really seem to get better, didnt get any worse... sometimes it wouldnt blow smoke at all either when driving or idles, other times it blew smoke while driving and at idle... But still i only did 2-3km.

Anyway, some videos.





And for those that think a wrx hatch can't tow a car and trailer....

Umm, whoops. Something a bit funny going on here.

hmmm looks like you have some issues in there, is that the light or fillings ?

Yeah, took the head to the engine reconditioner, all looks good, so thinks its the rings. Took a piston out tonight and going to get him to check it, suspect its not the right oil ring. Checked all the ring gaps and everything was sweet.

Yeah its the light, everything looks fine except for the pool of oil at the bottom of each cylinder. The bores are smooth as, no scratches.

Ok, its official, the rings are wrong.

Looks like, as the engine is an import legacy engine, the rings are slightly different to the ones supplied. The OD of the rings is right, which is why they fit and gave the right end gaps etc. Get the right rings tomorrow (hopefully).

I had somewhere between 3-4l of oil in it. only have the standard sump divider plates in it (aeration).
Pickup I had to shorten. Yeah had to shorten the pickup, unfortunately can't remember how much but 5-10mm off the bottom comes to mind. The dipstick seems to rest at roughly the same level as the standard sump, but yeah like any short sump, the difference between L and F will be more than stock.

How high is too high for oil bore issues? This did cross my mind at one stage.. but when you have a look at how high the bottom of the bores are to even the top brim of the sump its a fair way. Funnily enough, when i first checked the oil level in my brand new wrx it was an inch higher than the Full mark.. took it back to subaru and they drained 2L out of it (and it was still above the F).

Good to see that you have found the problem Andrew. Another step forward :-)

Make sure you use metal head gaskest & the thick ones . Worth the few extra $