Hi all TT engine gurus. I bought a spare engine a little while ago that had been diagnosed by a mechanic as having a spun big-end bearing on no 5 pot. I am just about to start recon/upgrade of that engine but am hoping that you guys can shed some light on the possible causes of a spun bearing - I don't want to fix the bearing and not the cause. The engine had just had the heads fully reconditioned and there were unresolved questions about the amount of oil in the sump. The engine was running fine but with a "not normal" noise which led to the bearing. SIMON, when will I get my clear sidemarkers, or at least an answer to my PMs. regards neddey
Oil starvation (bad oil pump), contaminated oil, overheating etc. There can be a few contributing factors, aswell as a poorly rebuilt engine in the first place being one of them which is also likely.
Oil starvation Thats the most common reason, a couple of seconds with no oil pressure and the bearing grabs the crank and spins. Particularly when the engine is working hard oil supply then becomes crucial.
i feel your pain suffered same fate with an NA engine last year. no known reason. best guess was that the galleys had filled with gunk and a brief period of no oil and it was all over. still drove 2000 km on a spun big end whilst saving for replacement. fair to say the engine was junk by the end (scored crank, scored cylinder, bent valves, ect ect) good luck:biggrin:
Why? Why? because you're unlucky. Sorry to hear that mate. yeah low oil pressure will do that especially if the bearings and crankshaft are rough. Are you going to rebuild or drop in a complete 2nd hand motor?
next year's project reworked motor + auto to manual change. the spun bearing is actually on a second hand motor, and I knew about it so bought cheap. It had suffered a broken timing belt and all that goes with that, and had the heads fully reconditioned so they are worth what I paid for the complete motor, (I was really sorry for the guy I bought it off). My plan is to fix the bottom end, and the problem that caused it, fit bigger turbos and split dumps, 300 deg fuel rail and larger injectors, larger intercoolers, I already have a full kakimoto (incl cats) 3" exhaust system and some engine bay bling, which I have started on. next years project.
id recommend checking your oil cooler return line. the restrictor in there may well be clogged up and have stopped all oil flow. i know mine had
