HAVING A PROBLEM WITH TIMING CHAIN SLACK?
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I BEEN HAVING PROBLEM WITH TIMING CHAIN SLACK. i just rebuilt the engine an i replaced everything from the crank, crank sprocket, heads, cam gears, timing chains, and now tensioners. the left side stays tight but the right side becomes slack when i bar the engine over. i thought i might have had a defective tensioner, so i replaced it an still the same issue. i also swapped the chain guides from left to right and the right side still stays slack. im pulling my gd hair out!
im thinking it might have to be running to get the tensioner pumped up?
im thinking it might have to be running to get the tensioner pumped up?
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Joined: Dec 2020
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Hey, I know this is an old thread, but I'm having the exact same problem with a 4.6 2V in an '05 F150 2x4. Changed timing chains because it was slapping bad. The drivers side lower guide was broke, the bottom of the hole for the mounting bolt, so the guide was hanging. Replaced chains/tensioners (Plastic junk) / guides. Tensioner gasket,one for sure was failed, i thought, slam dunk, fixed. Fired it up, and it's still rattling, just not quite as loud. Took off the valve covers and the cam isn't loose on passenger side, all rockers are OK, none broken. The passenger side timing chain has slack on the top guide. I noticed this barring it over when it was apart, but thought when the tensioners pressured up it'd go away. It's still noisy though. Anyone know what now? new slack adjusters? I'll pull the valve cover off and check the oil galley in the back tomorrow. Cams look good, no pitting or anything. Truck has 160KM on it.
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Joined: Jan 2015
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From: Southern Manitoba
I'm thinking in your case, you may be dealing with low oil pressure from the oil pump. To inspect it is the same procedure as the chain replacement but going a bit further and taking the crank sprocket off and then there are three bolts holding it on. Dont get confused when you install the pump again thinking one bolt is missing. The cover takes care of the last bolt to mount the pump. But, find out what is making the low oil pressure, the pump? or something with the engine like main and rod bearing clearances. Should be straight forward to fix if it is the pump.
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Joined: Dec 2020
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I'm thinking in your case, you may be dealing with low oil pressure from the oil pump. To inspect it is the same procedure as the chain replacement but going a bit further and taking the crank sprocket off and then there are three bolts holding it on. Dont get confused when you install the pump again thinking one bolt is missing. The cover takes care of the last bolt to mount the pump. But, find out what is making the low oil pressure, the pump? or something with the engine like main and rod bearing clearances. Should be straight forward to fix if it is the pump.
I replaced the pump when I changed timing chains.
Problem turned out to be a bent connecting rod, causing the bottom of the piston to hit the counterweight on the crankshaft. This was caused by a failed intake manifold gasket allowing coolant to drain into the cylinder.
I've got it apart now, but ford no longer makes connecting rods or other parts for the 4.6, had to get a rod off ebay
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american jcm
2004 - 2008 F150
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Mar 19, 2019 05:05 PM
