Moving the harmonic balancer one inch before getting the rotor to move can be an indication that the timing belt is stretched although you can only be sure of this by checking the deflection of the chain with the front of the engine off (if you open up the engine, it isn't that much more expensive to replace the part [about $40 for the two gears and the chain] - labor is the driver). There will always be a little slack due to gear play, etc.phish555 said:Got a call and they said i need a new timing chain for sure, and that they could move the harmonic balancer 1 inch before the rotor would move. I am going to go down there and have them show this to me. BUT, i also had a friend who is very knowledgeable about the 454 and said i could have a worn exhaust cam lobe.
One inch is not good, but not bad enough to cause your problem. Timing chains that are very much out of spec causes very hard starting. How many miles on your engine?phish555 said:Ok guys. I took it in for service. Got a call and they said i need a new timing chain for sure, and that they could move the harmonic balancer 1 inch before the rotor would move. I am going to go down there and have them show this to me. BUT, i also had a friend who is very knowledgeable about the 454 and said i could have a worn exhaust cam lobe.
What are your thoughts??
Ill give feed back from the service shop when i get back.
Things i have done so far: New fuel filter, new fuel filler cap, new rotor, coil, and distributer cap, and i have timed it.
I agree that it could if the camshaft were worn very badly. But if it was that bad, it should cause some other issues including missing, rough running, etc.gwcowgill said:An exhaust cam lobe worn could cause backfiring in the throttle body. As the cam lobe wears, it doe not release all the exhaust gasses into the exhaust manifold....when it becomes worn enough enough pressure is present (hot gasses) to ignite the incoming fuel when the intake valve opens. If you don't believe me try loosening up one of your exhaust valve adjusters!
I agree that this is low milage for a wear problem. Sounds more like a "catastrophic failure", like broken valve spring or badly burned valve.gwcowgill said:59K is awful low mileage for internal engine problems on the 454. I have seen some though that had some lack of lube symptoms when they set for long periods of time. Definitely low mileage for timing chain problems.
Now that you have found the bad cylinder it's time for a leakdown test to pinpoint the problem. The cam, timing chain, etc could all still be ok, may only be a burnt valve. what was the compression reading for cylinder #3? What about the others?phish555 said:Bob, GW, Paul, and 34'r, thanks for all your imput. Let me give you the latest.
#3 cylinder is dead. Wont hold compression. THe shop is going to check the cam this afternoon. At this point we are looking at rebuilding BOTH heads, and of course the timing chain and gears. I think even if the cam isnt worn, i will have him replace it too while he is already there. He said the injectors were good. Right now i am sitting at 2675.00 and he said that is most likely on the high side.