I just completed installing my rebuilt engine in my 05 STi. Car was purchased running but with suspected cracked ringland(s). I disassembled the engine and verified the cracked ringlands. For the rebuild, the machine work was done by Metro. Purchased parts are JE pistons (100mm), Manley rods, King bearings and ARP head studs. The oil pump is new from Subaru. The factory oil pressure sensor was resplace with a sender for a Prosport gauge. Before giving the engine fuel and spark I turned it over to make sure it was building oil pressure. I also left the top banjo bolt on the turbo loose to make sure oil was flowing. The car fired up immediately when cranked but I noticed a metal on metal grind. The car was quickly shut down after about 10 secs of idle. It sounded a lot like the starter was hanging up. I fired the car up again to listen closer and the car idled for about 15 sec and died!! I am at a loss. Thoughts?
Could be many things, who did the assembly? Did the shortblock rotate good after measuring and assembling it? Did anything possibly drop into one of the valve ports while putting back together? If it made it instantly it sounds like something didn't go back together properly rather then lubrication but would probably need to be opened up. Also I know Dave is the man but did you double check the valve lash really quickly? He is nearly perfect so doesn't make many mistakes so don't think that's the issue but good to double check
The assembly was done by me and everything was triple checked. I have built many different engines but this is my first Subie. All rotating parts were checked every step of the way including after the timing belt was installed and I spun the crank with a wrench. I spent a ton of time getting the valve lashes as close to the center of their tolerance as I could. Both the turbo and valve ports were kept covered/sealed until I was ready to drop on the intake and exhaust manifolds. I thought the same thing as you. The noise started immediately, at idle, so I didn't think lubrication right away (although I had proven it had over 90lb of oil pressure when cranked). The noise it made was almost a tinny sounding noise. My first thought was either the starter hanging up or that little metal shield on the bottom of the bell housing hitting the flywheel teeth. I appreciate any experience and trouble shooting ideas!
I should add that I did not detect any noises like this when it was cranked to build oil pressure! I don't know if it was the higher RPMs of idle vs cranking or what. That's part of what made my mind go to the starter hanging up.
Im assuming since you triple checked everything you also triple checked to make sure it was timed correctly?
Yes. I was really worried about the timing being off and the valves hitting the pistons. I installed the timing belt and then came back the next day to verify the markings were aligned per the service manual. I spun the crank by hand with a wrench nice and slow at first and it spun freely.
You mentioned checking for oil to the turbo. After tightening the feed line back down did you prime the turbo?
I did not do any other priming of the turbo. The banjo bolt I left lose was the one on the top of the turbo. The oil was flowing up out of the turbo so I assumed the turbo was primed at that point. Is that where I screwed it up?
You started the car with that top line to the turbo still loose and spewing oil? If so, then yes, I'd pull the turbo off and inspect that first.
Oh no, I torqued it to spec with new sealing washers before attempting to start the car. I had left the bolt loose when I checked the oil pressure with no fuel or spark. Just cranked the car for about 10 sec to build oil pressure.
Drained the oil on Monday night into a clear container. I let it sit and there isn't much at all settling out. I used a light quick this morning and didn't see anything still suspended. I'll use a brighter light tonight. While I was under the car on I checked the dust cover on the bell housing and it does look like that might have been rubbing. That would certainly explain the noise I was hearing. I can't get to the two 10mm bolts to get it off until I lift the engine. Could the no-start be a coincidence? Any thoughts on diagnostics before I pull the engine? Crank and cam position sensors? Fuel pressure?
After life got in the way for a while I am back at it! I have verified: 1) Fuel flow from the return looks good. I have not checked fuel pressure 2) Plugs looked good but were still wet several days after I attempted to start it 3) All four coils spark when I insert the plug and ground it 4) I removed the two outside timing belt covers and found the timing on the intake cam for Cyl #2 and 4 is off significantly while timing on the other 3 is still correct. What could have made that one cam be off by so much? Could it have jumped or is the only possibility that I assembled it incorrectly? If I assembled it incorrectly how did it ever fire up in the first place? My first thought was that the pulley was not seated correctly on the cam pin and spun/slipped. After more thought, wouldn't that cam pulley still be timed correctly but the cam and pulley would be off? I am seeing the marks on the pulley are clearly not lined up as they should be. My next steps are: 1) Pull cam pulley and make sure its correctly seated on the cam pin and check for signs of slip 2) Correct the timing 3) Compression check
Compression results are in and they leave me more confused. Cyl #1 and #3 are both around 90 psi and are within 1 or 2 psi of each other Cyl #2 and #4 (where I had a timing issue on the intake) are around 120 psi The consistency on the right side makes me think heads, cams, AVCS? Should I be concerned about the right side cylinders or blame it on the new build and continue with break-in before doing another compression test? (See the optimism there that I can get it to start).
Do a leak down, you should have no air coming out the intake or exhaust valves. If those are good you probably just got some fuel in there and washed the walls a little or else not enough oil in there. Put a table spoon of oil in each cylinder and try firing her up again once you know it's all good. also make sure you got the cam gears on the dowels correctly. Could be why they rotated.
Another question for those of you with experience timing these engines. When I was re-checking my timing I noticed the intake cam pulley on the drivers side seemed a little stiff. As you know, you have to rotate the exhaust cam counter clockwise to line up the timing marks. On my engine, if you let of the wrench it will snap back to it's resting position. On the intake cam, I was able to rotate the came clockwise so the timing mark is at the 12 o'clock position and it stayed there. I could definitely feel the valve springs being compressed but it didn't "snap" back like the exhaust pulley did. Around the resting position I am able to spin the pulley back and forth quite easily by hand so it does't feel the whole cam is binding. Is this normal or am I feeling the effects of bent valves? Maybe not bad enough to keep them from sealing (good compression) but enough to bind in the guides slightly?
Ladies and gentlemen, it lives! Pulled the valve cover off the drivers size and pulled the cams out. Found the center journal on the intake cam did have some light scoring. Not sure what caused it as oil flow seems good. Possibly debris in passage from machining? At any rate, Metro Engine got the journal cleaned up. Compression check showed ~135 psi on all four cylinders. She fired right up with a little smoke and settled into a good idle. Time to put some miles on it and break it in!
Thank you! Need to get a boost gauge and an AOS installed, get it broken in and then the real fun can start!
Thanks. I'd prefer a can style like the IAG or Crawford. I like that it gives more volume for the separation to occur.
