Ok, me and the old man spent a good few hours on the engine today and heres the outcome: We removed the cylinder heads, which look in top condition although the buckets will be reshimmed before putting back together (no hydraulic tappets on the STis). <u><b>PIC OF CYLINDERS 3 AND 1 IN THAT ORDER</b></u> (everything looks normal) http://img.photobucket.com/albums/v11/T ... G_0283.jpg <u><b>PIC OF CYLINDERS 2 AND 4 IN THAT ORDER</b></u> (no 4 looks a bit oily) http://img.photobucket.com/albums/v11/T ... G_0282.jpg <u><b>REMOVED THE SUMP </b></u>(bits of bearing on the oil pick up and generally scattered about) http://img.photobucket.com/albums/v11/T ... G_0285.jpg <u><b>PIC OF THE CRANK AND CONRODS FROM BENEATH </b></u>(more bearing at top of pic) http://img.photobucket.com/albums/v11/T ... G_0287.jpg Not 100% sure which big end has gone, think its no 1 .Tommorow the block will be split and then well know which for sure. All in all a good day, need to get the garage a little more organised though! []
You can tell you use NF [] Looking at where the swarf has been thrown to, Id be looking at the two middle big ends as its inline with those. Coming along well, don know if youve seen in the past on scabbynet but Bob recommends replacing the donut oil cooler when a bottom end has gone as you cant flus it fully!
The engine has been rotated on the stand at various times with the sump still on jim so the swarf could of moved around i suppose, know what your saying though, hope it isnt mind! Dont want the block to be fooked! [:0][!] Andrew mentioned the donut thing, is it oil/water heat exchanger?
Yes it is. Is no.4 oily or just more carboned up, it is the first cylinder on the fuel rail so will be slightly richer than the rest. Andrew...
Not sure Andrew but if you think it was due to the fuel rails then surely theyd get progressively worse from supply to regulator[?] Its only cylinder no 4 that seems to have suffered, maybe thats the cylinder with the failed bearing?!
Ok, split the block today and now know for sure which bearing has gone, its actually the bearing on cylinder number 1! This is the first to get supplied with oil so seems very strange why it has gone, also the top half of the big end bearing of cylinder number 4 has been damaged too!! [:0] <u><b>PIC OF DAMAGED BEARINGS</b></u> http://img.photobucket.com/albums/v11/T ... G_0299.jpg <u><b>PIC OF DAMAGED CRANK </b></u> http://img.photobucket.com/albums/v11/T ... G_0309.jpg So what has happened?! Andrew is it possible that the oem knock sensor could be knackered and any knock has gone undetected? I remember you saying that all looked quiet but we were getting some activity on the Knock Link which i assumed could have been background noise after fitting the front mount (pipe work etc). Just trying to understand whats actually happened here.
I can see were the swarf colour came from now John, I may be wrong, but the frequency of the knocklink is set to listen for Det, so maybe the bearing failure noise will be a different frequency, hence no warning??
As most Knocklinks get fitted set at maximum sensitivety, they do seem to pick up a broader range of noises, including thrown up stones etc. (just gently tap the block with a spanner to see) Like John Im a little suprised it didn flip its lid or at least go steady amber[?]
(...oh, and John, as this thread is (hopefully[]) going to run for a while and many pages maybe move to technical[?][]
There was some noise reported by the ECU inline with the first green that you were seeing on the KL, neither was of sufficient amplitude to cause concern wrt knock and could be considered background noise. To give you some idea of the level it was around 6-9, maximum is 255, Bob had set the knock threshold to 75 (it varies from car to car but that level is generally around the threshold of the first green on the KL). Whilst the previous log I had take showed a lower background noise level that was before you had fitted the FMIC. I thought you had said that you had seen a big red on the previous day when giving it some stick? This would indicate that the KL was working. I doubt that a damaged big end would generate noise in the 6KHz region that the KL and ECU filter. Andrew...
I thought maybe there could have been a problem with the oem knock sensor but obviously not from what you say. My concern was that if i rebuild the engine and a vital sensor isnt working that this could happen again sooner than later. Anyhow ive phoned around a couple of places this morning and it would seem very common for number 1 to go first (STi/UK)! A machine shop in blackpool say that they grind more subaru crankshafts then any other type and usually its because of a spun/knackered bearing on number 1. Also spoke to Oliver a RCM who says its also number 1 that commonly goes and he thinks its number 1 that suffers first if the pressure relief valve on the oil pump sticks at high speeds. All in all its reassuring to know that what has happened is what usually happens! More importantly i think an uprated oil pump is a must in any case and also the correct method of oil change is important in prolonging the life of all the bearings especially the latter ones. Steve, feel free to move this to technical, would do it myself if i could/knew how!
So have you decided what to do with it? New crank, bearings, rings, oil pump and oil cooler would be the quickest/cheapest option now you know what damage has been done. Andrew...
