MarcFX4

My truck started making a loud banging noise this morning. My buddy told me it's one of the pulleys that spin the serpentine belt. He's right about that cause it's moving a lot.
Now my question is could it also be my timing chain, and how much could it cost me to get both items replaced?

Austin97

Take the belt off and run the truck for a few seconds and see if it quiets down. If it does you know it's related to the belt. Getting a serp belt replaced should be under $100 but replacing the timing chain, tensioners and guides, which all have to be done if you take the chain off would run closer to $1000, but it's not very common for them to go bad.

MarcFX4

How long would it take a shop to fix the chain and tensioners??? My buddy said the radiator would have to come off, is that true?
I don't have the space or tools to do it myself.

Austin97

No, there is plenty of room to pull the front cover without pulling the radiator. It would probably take me around 5 hours to change the timing components assuming you have a 4.6 or 5.4. I've never really messed with a 4.2, but I believe they're easier than the v8s because there's one cam and one chain. If you can remove the serpentine belt your self you can rule out all the pulleys and accessories though so I would start there. It could definitely be a pulley.

MarcFX4

Yeah the pulley is wiggling all over the place. I got the 5.4 V8. I might give it a shot tomorrow.
So pull the belt off turn on the truck and if there's no noise then it's most likely the pulley. Thanx.
I'll post back on here if I was able to fix it.

Austin97

Yeah don't let it run too long because the water pump won't be spinning It would take a while for any damage to happen, just keep in mind that the pump isn't circulating the coolant. It should only take a few seconds of running to know if it's making the sound or not.

BolletuH

Hmm didn't know the 4.2 was an OHV

Mod (Ret.)

Huh? Valves are in the heads. One cam in the center of the block, driven by chain from the crank shaft.

Where you thinking overhead cam perhaps?

BolletuH

Read closely... He says it only has one camshaft, and one chain. Meaning the engine can only be OHV because SOHC would require two camshafts and two chains. Also note the 4.2 is a v6 meaning that the whole inline configuration doesn't apply here. Either he is wrong or I'm misunderstanding common logic of camshafts.

Austin97

No lol, Overhead Cam is when the cams are in the heads, like the cam is overhead of the cylinder... and the cam pushes directly on the follower which depresses the valve, which means you use less valve train components... OHV is Overhead Valve , which means the valves are overhead of the cylinder, also called a pushrod motor, which like you said has the single cam in the block, pushrods and rockers that depress the valves. Old old old motors had the valves in the side of the cylinders instead of on the tops like any motor in the last 50 or 60 years.

See the terms OHV and OHC actually have nothing to do with the heads on the vehicle, it is actually talking about the location of the valves and cams.

Yes the 4.2 is an OHV just like the 3.8, they're the same family of engines. The 4.6 and 5.4 are OHC motors. Some are SOHC single overhead cam and some are DOHC, dual overhead cam. 6.8 v-10s are also the same engine family and are only SOHC as far as I know.