Horrible noise.
Thread Starter
|
Junior User
Joined: Aug 2006
Posts: 64
Likes: 0
Horrible noise.
I put a new cam in my 460 last week. I rebuilt the engine 4500 miles ago but didn't likethe first cam I chose. Within the first 50 miles of running th new cam my motor started getting hot. It's a manual by the way. It is almost over heating in 10 degree weather and when it gets hot my oil pressure is dropping. Now it is knocking above 1800 rpm. My oil has turned gray in color. I tried pulling the plug wires to narrow the noise. When I pulled #7 the noise started running from idle up. None of the other wires changed the noise. Help!!!
Fleet Mechanic
Joined: Mar 2004
Posts: 1,398
Likes: 17
From: Hesperia, CA
Its been a long time since I have troubleshot an engine, but if I remember right the noise increasing when you take the load off means a piston. In the case of the gray oil that means coolant and since the #7 seems to be the only culprit I suspect a blown head gasket in that cylinder. Pull the #7 sparkplug out and fire her up. If it blows water everywhere then the head or gasket is gone. The cam shouldn’t have caused this. It probably was just a coincident that it happened about the same time. I definitely wouldn’t run it anymore until it’s fixed. No telling how much damage you could do to the engine. Also the overheating is also a symptom of a head gasket.
Junior User
Joined: Oct 2007
Posts: 83
Likes: 0
hi, take things one at a time, find the overheating/water loss problem first, ie pressure test, remember you have had the intake off, possible head gasket failure, diluted oil ?? with water, then worry if you have an internal engine problem not caused by recent cam change. hope it works out for you
Posting Guru
Joined: Dec 2000
Posts: 1,793
Likes: 2
From: San Diego CA
Pull all the plugs and spin the motor, watch out for spitting coolant. If no water spits out the spark plug holes do a compression test and leakdown test. If both pass I'd say your leaking coolant into the oil at the intake manifold or the water pump timing cover area. As to the noise, post back the compression test results before further comment.
