4.0 sohc timing chain

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Mar 27, 2003 | 12:11 PM

musclemaker

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4.0 sohc timing chain

i am in the process of purchasing a used 1997 explorer with 4.0 sohc. the vehicle was idling rough and making engine noise in the front. it would not pass emissions inspection. the dealer is having the timing chain tensioner replaced...and now they are talking about doing more work....i am assuming they are going to replace the timing chain(s) and guides that i have read here in the forum are a problem. I am curious as to how the sohc engine valve train opperates. (i am having trouble picturing how a single oh cam can operate a v6 valve train)
can someone refer me to a free online site where i can view a diagram of the timing chain configuration, or describe to me how the valve train works in this engine?

Mar 27, 2003 | 03:45 PM

Ford_Six

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From: The Big, Oregon

4.0 sohc timing chain

SOHC just means that there is one cam per head- Some companies refer to SOHC v-type engines as twincams, etc. It does have two cams, with a long chain going around the crank sprocket, up to the right (pass) side bank, down under the tensioner, up to the left bank, and back to the crank. There are also a couple of sliders in there that keep the long runs of the chain from whipping around and upsetting the timing.

Mar 27, 2003 | 04:31 PM

musclemaker

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4.0 sohc timing chain

thanks so much for your reply. now it all makes sense.

so, in your opinion, after having these parts replaced (at 134,000 miles) this area of the engine should not give me any problems for a very long time?

any feelings on the engine or vehicle in general?

thanks again for your help!

Feb 12, 2004 | 07:30 PM

GizmosStang

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Somewhat correct on the 1 cam per head but the engine actually has a conventional timing chain setup, only difference it instead of the normal "Cam Gear" there is a Jack shaft running the length of the engine the Left Cam is driven by a gear in the front end of the motor the right Cam is driven by a gear in the back on the motor on the jackshaft