My LC2 has developed a “knock” while running.
From what I can tell it ISN’T, rather SHOULDN’T BE, for the following reasons:
Coolant in oil: The oil was changed after a few minutes of run time and a quick drive… and didn’t have a trace of a “milkshake” in her. There was some worry a month ago that the dribble of oil that got in my block would toast the bearings. Heck, it is still sitting slightly “fuelled” in a bucket in the garage.
The car wasn’t over-rev’d during the first test drive… saw MAYBE 3000rpm and 8lbs of boost before the front wheel fell off (see: http://www.turbobuicks.com/ubb/Forum29/HTML/000225.html for more details). There was NO damage to anything under the car related to the engine or suspension.
Also, the next day AFTER the rotor was replaced it ran fine and quiet…
It was just upon restart yesterday that the puppy started making some noise.
Things I am leaning toward:
When I has doing the “refresh” on my engine I didn’t have a torque wrench at the moment I was doing my timing chain (but DID for everything else) and had already re-installed (and “glued”) the front cover. I did the “torque by feel” thing (flame away) which has been VERY successful in my SS’s 350 (over 6000rpm many times) (yes, I know: Buicks aren’t Chevys). And I fear the it may have backed itself off. Would this introduce a “knock” or “clank”?
There was an odd “clink/clunk” that happened once while rotating the engine by hand at the flywheel… leads to believe something is loose.
There was also a “procedure” used while changing out the rear main seal that had the crank “popped” out of its mains so that the block side of the stock rope seal could be removed. My Dad, the licensed mechanic and former TR owner, did this but said: “If you pull the crank up too far you can tweak a rod and bend it”.
Since there is NEVER a sure thing with cars… this could have happened too.
I am going to have the Torque Converter bolts checked for looseness and the flywheel checked for cracks.
The oil is still visually clean… has about 60kms on it. But the filter hasn’t been changed… and I will cut it open for inspection.
Also the starter has failed… it is being replaced tomorrow (with a 95ish LT1 F-body unit)
I’ll have to check for broken rocker shafts too…
And worse case: Pull the pan… and the mains… and rod caps… and inspect.
Would it be odd that with 25-40lbs of oil pressure at hot idle (60+ cold) that it could still spin a bearing? It still has these figures with the noise.
Things we have checked for:
False knock… my brother wrapped a towel around the stock free-hanging (read: open and dangling) down pipe… noise was still present.
Checked for a loose elbow at the turbo… and loose DP bolts… still “knocking”
Believe me I have spent about 2 hours reading up on the “possible” false knocks and real causes and inspection manners… but I have found nothing that might equate to the timing chain torque specs… which to date… is my only oversight.
Sorry for the novel, but I have tried to cover as much detail as possible… need more… just ask
From what I can tell it ISN’T, rather SHOULDN’T BE, for the following reasons:
Coolant in oil: The oil was changed after a few minutes of run time and a quick drive… and didn’t have a trace of a “milkshake” in her. There was some worry a month ago that the dribble of oil that got in my block would toast the bearings. Heck, it is still sitting slightly “fuelled” in a bucket in the garage.
The car wasn’t over-rev’d during the first test drive… saw MAYBE 3000rpm and 8lbs of boost before the front wheel fell off (see: http://www.turbobuicks.com/ubb/Forum29/HTML/000225.html for more details). There was NO damage to anything under the car related to the engine or suspension.
Also, the next day AFTER the rotor was replaced it ran fine and quiet…
It was just upon restart yesterday that the puppy started making some noise.
Things I am leaning toward:
When I has doing the “refresh” on my engine I didn’t have a torque wrench at the moment I was doing my timing chain (but DID for everything else) and had already re-installed (and “glued”) the front cover. I did the “torque by feel” thing (flame away) which has been VERY successful in my SS’s 350 (over 6000rpm many times) (yes, I know: Buicks aren’t Chevys). And I fear the it may have backed itself off. Would this introduce a “knock” or “clank”?
There was an odd “clink/clunk” that happened once while rotating the engine by hand at the flywheel… leads to believe something is loose.
There was also a “procedure” used while changing out the rear main seal that had the crank “popped” out of its mains so that the block side of the stock rope seal could be removed. My Dad, the licensed mechanic and former TR owner, did this but said: “If you pull the crank up too far you can tweak a rod and bend it”.
Since there is NEVER a sure thing with cars… this could have happened too.
I am going to have the Torque Converter bolts checked for looseness and the flywheel checked for cracks.
The oil is still visually clean… has about 60kms on it. But the filter hasn’t been changed… and I will cut it open for inspection.
Also the starter has failed… it is being replaced tomorrow (with a 95ish LT1 F-body unit)
I’ll have to check for broken rocker shafts too…
And worse case: Pull the pan… and the mains… and rod caps… and inspect.
Would it be odd that with 25-40lbs of oil pressure at hot idle (60+ cold) that it could still spin a bearing? It still has these figures with the noise.
Things we have checked for:
False knock… my brother wrapped a towel around the stock free-hanging (read: open and dangling) down pipe… noise was still present.
Checked for a loose elbow at the turbo… and loose DP bolts… still “knocking”
Believe me I have spent about 2 hours reading up on the “possible” false knocks and real causes and inspection manners… but I have found nothing that might equate to the timing chain torque specs… which to date… is my only oversight.
Sorry for the novel, but I have tried to cover as much detail as possible… need more… just ask
