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View Full Version : weird engine noise


perley03
03-28-2006, 06:39 PM
just rebuilt my friends 03 pred....got wiseco higher compressioin (11:1), new valves and seals. i double checked all tolerances before we put it all together. double checked valve clearance. all fine. we fired it up and there is a weird noise coming from the side of engine with the cam chain. it is a knockin noise. the tension on the cam is fine. it sounds like its coming from the top end, only on that side though. every tolerance on the top end has been double checked. it also has a new wrist pin. help anyone?????
Specialist
03-28-2006, 08:11 PM
hows your timing looking? Maybe just the intake or exhaust cam is off by a couple teeth causing some contact.
wolffie
03-29-2006, 06:48 AM
post up something on www.predatorowners.com :)
CHADHIX
03-29-2006, 12:38 PM
We run in to this at the shop, The decompression part of the cam will make noise untill it gets well lubricated. We run my machine on an easy ride and it totally went away.It took us a while to figure out what was . We also took emery cloth and cleaned out valve buckets. Not saying that this is what it is but it sure sounds like it.
MentalState
03-29-2006, 01:43 PM
Thats what I was thinking...Lube....Did you purge the oil system per the manual when you started it....
perley03
03-29-2006, 02:59 PM
no we didnt purge the oil system...the repair manual didnt say anything about that...i went through chapter by chapter making sure everything was right so i didnt have to take it apart again. damm. well i'll have to see about that its parked in the garage now till the weekend i'll see if i can come up with something. thanks guys
perley03
03-29-2006, 05:15 PM
Originally posted by Specialist
hows your timing looking? Maybe just the intake or exhaust cam is off by a couple teeth causing some contact.
where would be the contact be at if it were off just by a couple of teeth...i think the exhaust is off by 1 tooth because it was a b*tch getting both cams timed...would that make that much of a difference???
1fstpred
03-30-2006, 06:15 AM
I ran into the same thing when I put my motor back together. ChadHix has too. The decompression arm on the exhaust cam is popping and sounds like a knock until everything is lubed. Take out your spark plug and turn in over by hand... you will see what I am talking about.