RomRaider

That's pretty logical logic.

Reading this makes me want to tear an engine apart.. that can't be good.

Let us know what you find Gabe!

Well, I got one of those harbor freight crappy leakdown tester which is only good for comparing cylinder to cylinder (but hey it was only 30 bucks). Anyway, I took the plugs out and it was what I thought. #3 (the same one that broke a ringland) sparkplug is drenched in oil. #3 actually has less blowby through the breathers than #1. Air coming out of the intake and exhaust is about the same between the two, with #3 letting a bit more slip past the exhaust it seemed, but made a negligible difference in the gauge reading. So it tells me that the valves are fully seating. I cannot tell which valve it is on #3, but it is one of 4 of them (valve guides or th valvestem seal). At this point (taking into account that I will want to do future upgrades) and assuming it is not just a valvestem seal, I should just replace all the valves and valve guides.

Basically it is the worst case scenario.

From all of the online research I have found, I cannot tell I can even get my hands on OE valves for the 07 STI. The only website that lists the 07 STI valves is here:

http://www.subarupartsforyou.com/cp_par ... %2C+Valves



These are the sodium filled exhaust valves that I do not even have. If they are a direct replacement, then that would be perfect since they can transfer heat into the head faster.

So far out of pocket (which includes buying a hoist and leveler for 160 bucks and other misc stuff you need when rebuilding an engine) expense for me has been 3529.95. Without the 587 in donations I received, it would have been 4116.95. Granted much of this was upgrade, but a good portion of it was simply stuff that had to be replaced.

So if the OE 04-06 exhaust and intake valves fit, time to just replace them all. To do this myself (except taking the heads bare to a machine shop for cleaning and valve guide replacement), the extra cost now is going to be 1266.00 or there abouts, probably closer to 1500 when all is said and done.

I guess tonight its time to start working. I'll at least get the engine ready to be pulled and yank it tomorrow night. I am hoping to get it apart by the end of this week, inspect the #3 piston (just to make sure) and then start taking apart the heads. Should have done the head in the first place, but when you have a family to support it becomes hard to justify and extra 1500 bucks that you may or may not need. Turns out I did need it. If there was a way to unload the car I would. I put 10k down on it, so there is only 25k left on the note. So even if I was able to get rid of it, I basically just threw away 15000 dollars.

I guess I just have to wait more time now is all and make the car payment on a car that does not move along with insurance until I can get it running right.

Sorry to hear you have to rip it apart again Gabe... Sent you a PM...

Damn Gabe hang in there bud, you'll get it right just take your time and do it right. I definitely understand about the financial part, this stuff gets very expensive.



Did you get that stuff straightened out?

It'll be back together eventually. When it is, I will be happy. Hell, I was happy as a kid in a candy store when it started up right away on the first try and for 20 minutes there while it was running fine, I was all grins until it went bad. The more I think about it, the more I think that it might just be simply a valvestem seal. Those heads were cleaned with brakeclean and although brakeclean is not "supposed" to corrode rubber, since they sat so long exposed, the seals may have cracked and popped off that head. Knowing my luck though, they will all be intact and I will see a guide that is halfway pushed out once I pull the heads apart. The only good news is that the full gasket kit I bought came with seals and retainers. So I only need to buy valves, guides and gaskets. I already have the bottom end initial breakin done and all fluids at the ready.

I had a huge argument yesterday with one of my friends on whether to get OE Sodium filled exhaust valves and OE intake valves vs Ferrea. I tried explaining to him that I want the valve to remain cool, not that I want the valve to remain hot and straight. Obviously, the stock valve took the heat but the components around it (the guide) could not handle it. With sodium filled valves the heat will transfer into the guides and head better where it will get cooled. I imagine all the times I shut the car off hot did not bode well for the exhaust valves in that one cylinder that was running lean. It is going to be a street car, a fast one, but still a street car. It won't have cool down laps and I only need 7k rpm anyway.

BTW, I need to double check my logs, but roughness monitor reports the cylinders incorrectly. I am pretty sure when it blew and when I monitored it after rebuilding it, it was #4 according to the logger that was misfiring, but #3 was the broken one that was actually misfiring.

FWIW

When I blew #2 on my 05 LGT engine the roughness monitor showed the correct cylinder.

How long have you run it?
Did you do a compression test?

Have you pulled the front covers and double checked the timing belt/cams?

Its common for a fresh motor to smoke a lot....

It is only occurring on one piston, so it is not the timing belt. The car has run for about 40 minutes total. I could post pics of the sparkplugs, but you can tell in that 40 minutes, the car ate 1 quart of oil through #3. With that much oil consumption, I would have other symptoms if it were the rings or pistons. It is the heads. I did a leakdown and since I did not go out and buy a real leakdown tester, basically I could only compare #3 to #1. They had the same numbers and held 100 PSI just fine. #1 actually leaked more air into the crankcase than #3 (which has the oil drenched plug). I am really leaning toward a valve stem seal. It ran fine for 20 minutes, then the problem happened. Something broke or fell off on that cylinder while idling. I plan on getting it out this weekend and getting the rest of the diagnosis done. The sparkplugs show that each cylinder is burning a tiny bit of oil, but I expect this. It is nothing out of normal. The plugs look brand new still (except #3 which looks like it ate a quart of oil and is completely black). Also, the oil that is left looks brand new. There was no exhaust gas going into the crankcase. Catch cans are completely dry as is the tubing. It smokes idling and when you rev it up a nice cloud of blue smoke chokes my neighbors. It is really bad, like a valvestem seal is just gone or the guide is completely trashed. Since it happened at idle and so abrubtly, I am guessing it is a valvestem seal. That is an easy fix as I have the seals and new keepers already. If that is the case, while it is out, I will probably clean and relap all of the valves and replace the seals and keepers all around.

The definition is incorrect on the 07 STI at least. I need to double check, but I don't have my logs here at work.

It is either correct on all of them or wrong on all them - it is a standard SSM parameter. That is assuming that it is always an accurate means of determining misfire in the correct cylinder 100% of the time anyway.

I was thinking of this yesterday. I will double check my logs tonight, but since the missfire counter relies on the crankshaft sensor, it could easily show the wrong cylinder missfiring.

I checked my logs and it seems that #4 likes to report missfires that are occurring on #3.

the layout is like this:

front
2---|---1
4---|---3
tranny

firing order 1-3-2-4

I get small counts (1-2) on #2 and #3 and large counts on #4. Same happened when the engine went (#3). I was using test release 785. I guess the sensor just is not very accurate. I do know from 2 experiences now that if I get large counts on 4, then I check 3 (passenger side) and that is the piston that is actually missfiring. Maybe Subaru fudged up on their code, who knows.

I am going to do a dry compression test today just to have a look at the numbers before I rip it apart. As long as they are all close, I will not even bother removing the #3 piston and just take off the passenger head. I am betting it is a valvestem seal. The cylinder is holding pressure, but numbers would be nice and a real leakdown tester isn't going to tell me much than I already know.