![]() So you have one group of owners blessed with an engine that doesn't burn excessive oil and is changed regularly (or at least as dash reminds) but doesn't know to change timing set at 100K and loses engine. It's a thinned out liquid leaving behind sludge and destruction. Eventually you have 2 quarts of oil doing the job of 5 quarts. But the situation goes downhill exponentially as time goes on. So not checking oil at that point isn't an issue. On the engines with oil consumption issue can still "live" early on in the issue because they do not lose enough oil in between oil changes to compromise oil pressure. The engines that failed (rod knock, smoking, hole in block) all had same bottom line: low oil pressure lack of oil. I'm sorry you had to replace more than once to achieve result. Simply waited for dash to day change oil. No owners were aware of engine using oil. Must be a slower "eating" of metal whereas the other guide sees more stress and shrapnel causing chaos and catastrophic failure.Īll owners claim no noise or warning in a timing failure. Rare for me to see top guide intact, so must not cause enough damage as it goes. Leads me to believe that when the right side guide fails, it's a fast end of life process from there. Timing sets fully operational and complete other than top guide is missing all of the upper rail usually. Oil change sticker withing 3,000-3,500 miles of last change. Oil pan and VVT solenoid screens FULL of metal. The rebuilds from oil consumption (of engine failed or not) is the opposite. VVT solenoid screens are full of metal from guide that shredded. The bores are also good, hash marks are visible and a hone will be fine. Crankshaft is clean and a polish is all that's needed. Most of my rebuilds due to timing system failure have beautiful engine internals. I guess it doesn't matter which piston fails, it's a full rebuild or replacement to put back in the road. ![]() But for some reason #2 is usually in pieces or blown through the block. #2 & #3 rise and fall in unison opposite of #1 & #4. Like in the obove posts, I see #2 as the victim/culprit for final destruction. Therefore they do not get any correspondence from GM or have serviced at dealership where issues are known and attended to. All of the engines I have done (save for 1), are second or third owners. None of them check oil level in between or have heard of the oil consumption issues or timing chain component failures. I have rebuilt several of the DI 2.4 Ecotec engines and after taking to the owners it seems they rely solely on the dash warning to change oil and fter. Donor2 looks like it had regular oil changes with synthetic oil (just my impression). Here are some comparison pictures of the Donor1 and Donor2 cylinder head/valvetrain area. I am in the process of replacing the timing chain/guides/tensioner on that one before installing it, as well. I'm hopeful for the Donor2 engine (the 3rd engine). I had replaced the timing chain, guides and tensioner on this engine before installing it in my kids' Equinox, and this did not fail. ![]() The conrod and wristpin of the #2 cylinder were still intact. The valves did not drop in that (or any) cylinder, as they are all still in place - though the valve stems on the #2 cylinder are bent from when the piston parts went flying. Ultimately, I think different episodes of low-oil-level starvation led to increased wear and failure of the #2 piston. ![]() Also, the exhaust manifold nut/studs broke at the #1 cylinder when swapping the exhaust manifolds (I had to helicoil in new studs), so that made me think that that area of the engine may have had higher running temps or something due to oil starvation from a clogged oil passage (this is just me theorizing). In the other thread, I posted pictures of how coked-up the valvetrain area was. I believe the Donor1 engine (the 2nd engine) led a rough life before we got it. The original engine in the Equinox definitely failed by the front timing chain guide failing and the engine skipping time and then bang!-crash!-boom! This was the result of oil consumption due to piston ring wear and various oil-starvation (low-oil-level) incidents.
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