4.0 SOHC noise?

[chinesemechanic]

I have 97 explorer sport 4.0 sohc with about 140,000 on it. the problem I'm having is when i first start it i get some hellacious clanking sound coming from the engine. i think it sounds like it is coming from the back of the engine but from the bottom somewhere. it is really loud on first start up and until it gets fairly warm. i passed another explorer today and it was makin the identical sound, so i didn't know if this was some kind of common problem with the sohc.

 

[manaen]

search for timing chain and SOHC in this forum, and you will find your answers. If your lucky it's just the front tensioner, there is an update for that motor. The new part has an oil reservoir built into it, the factory ones had a bleed off problem.

Yes, there is a known timing chain issue with these motors, there was an update in 01 or 02 to fix the issue.

 

[ibgary2]

Engine noises

Welcome chinesemechanic,

These engines have a perpensity to eat up the timing chain adjusters. You have two in particular that will be affected, one is in the front of the left cylinder head, and the other is at the rear of the right cylinder head. There are a couple more timing chains inside the engine, but they seem to last longer.

The reports I've read on the upper chains indicate they make a lot of noise in the 2500 to 3000 rpm range. Pull the valve covers and you can inspect the tensioners and see if everything is getting enough oil. You can also put a wrench on the camshaft to check for play. I found plastic chunks from my tensioners in the valve covers and oil pan.

Good luck,

Gary A