#59815, "Shit! Switched to Mobil-1 Synthetic and now rod is a-knockin'" Sep-20-03 08:01 PM by dougie2
I switched to Mobil-1 Synthetic 15w-50 and now, less than 50 miles later, I have a rod knocking pretty good. Drained the oil and found it glittering with bearing shavings. It sounds like only 1 rod... probably #3 or #4. This SUCKS!
I'm using Eagle rods, JE pistons, Clevite 77 bearings, and a Melling oil pump. Oil pressure never dropped and the engine was still full of oil... the oil is still fresh and transparent. I switched from conventional 10w-30 to the synthetic ~1200 miles after the rebuild.
Rods were balanced within 0.1g and rod caps torqued per Eagle/ARP specs. Bearings were properly lubed when installed.
WTF happened? I'm stumped! I can only narrow it down to the motor oil. I'm pulling the pan tomorrow.
#59817, "RE: Shit! Switched to Mobil-1 Synthetic and now rod is a-knockin'" In response to Reply # 1 Sep-20-03 08:23 PM by dougie2
Yeah, switching to Synthetic too soon is the only possible reason I can think of. What sucks is I just got the car registered for street-driving and NEED to drive it on Monday. I guess I'll pull the pan, check things out, and replace all 4 sets of rod bearings. Hopefully I can get a set on a SUNDAY!
Here's what synlubes.com says about it:
"We prefer to wait at least 1,500 miles before switching over a new engine to synthetic lubricants. The seating of rings and wear in of other engine parts usually occurs within the first 500 miles and should definitely have been accomplished by 1,500 miles on today's new engines. Under 1,500 miles you should follow the manufacturer's recommendation for drain intervals and break procedures. Furthermore, waiting to at least 1,500 miles gives you the opportunity to assess the mechanical soundness of the engine and the opportunity to report any unusual conditions that may indicate a latent mechanical defect in your new engine. If there is any question about the mechanical soundness of your new engine do not install any synthetic lubricants. "
#59818, "RE: Shit! Switched to Mobil-1 Synthetic and now rod is a-knockin'" In response to Reply # 2
I just remembered I was right at 1000 miles on the re-built engine. I dropped the oil pan and the engine was left with no oil for about 7 days while I performed upgrades to the car's exhaust. That's when I added the Mobil-1 Syn. 15w-50. Again, 50 miles later the rod started knocking... I immediately shut it down. I hope I can just replace the bearing and not pull/reuild the engine again. I do have a backup block though. *sigh*
It's all part of the sport, though... ya gotta pay to play.
#59819, "RE: Shit! Switched to Mobil-1 Synthetic and now rod is a-knockin'" In response to Reply # 3 Sep-20-03 09:13 PM by Raven457
Yeah, time to swap out the rod bearings, cross your fingers and hope for the best... good luck, man. Double check the oil passages on that journal while you're in there, just in case
Autozone or a store like that will probably be your best bet for parts though, that's gonna suck.
#59826, "RE: Shit! Switched to Mobil-1 Synthetic and now rod is a-knockin'" In response to Reply # 5 Sep-21-03 04:07 AM by xEclipsE RaceRx
Ouch Doug! That sucks, same problem as me, just not to my extent, be happy why did you want to change to full synthetic anyways?
PS: If you need an xtra hand, cuz Matt aint there or something, I'll drop by. (lol couldnt do much, but grab ya a coke or something tho) 1999 Mitsubishi Eclipse GS 10th Anniversary OZ Edition Check Out My Site For Pix http://mywebpages.comcast.net/EclipseRaceR/MyEclipse/VIS%20CF%20Hood/
#59835, "RE: Shit! Switched to Mobil-1 Synthetic and now rod is a-knockin'" In response to Reply # 7
i wouldn't recomend changing to synthetic that soon id wait longer but thats me...
there are a couple things taht i can think of as the cause
1 draining all the oil for aweek probably left the pickup tube dry and maybe the oil pump lost its prime, that would shoot air into the oil system...
theory two the oil at 15w was too thick and couldn't provide enough lubricating properties for the stock oil celarances...
theory 3 oil pump hickuped..
Bill
You can have it cheap, fast or good. Pick any two.
If you want it cheap and fast, it's not going to be good. If you want it cheap and good, it's not going to be fast. If you want it good and fast, it's not going to be cheap.
#59838, "Rod cap now off, bearing diagnosis...." In response to Reply # 8
Well, contrary to my guess, it was rod #1 causing the knock. The bolts came out of that rod cap a little tighter than the others and the oil on the bolts was gray from bearing material. Pulled off the cap and the bearing has significant wear on one side only, approx. 1/2" wide. I'm still stumped on the cause... I still think it was related to the motor oil. I'm going to replace these Clevite 77 bearings with Mopar bearings and check the clearences. I'll get pics up ASAP.
#59842, "RE: Rod cap now off, bearing diagnosis...." In response to Reply # 9
what were your clearances on the bearings?
Bill
did u use plastiguage to check?
You can have it cheap, fast or good. Pick any two.
If you want it cheap and fast, it's not going to be good. If you want it cheap and good, it's not going to be fast. If you want it good and fast, it's not going to be cheap.
