97 sohc weird engine noise

[97FordxSport]

I own a 1997 Explorer sport 4x2 with the 4.0 liter v6 sohc. My x has 82,000 miles on it. I have this weird noise, that is hard to discribe. It is deffinatly coming from the engine area. It sounds like clicking or crackling. I can only hear this noise during acceleration. Once the noise starts i can make it stop by either easing up on the gas peddle or accelerating harder. I don't know why but the noise seems to happen less right after i fill the gas tank. I have tryed all levels of octain gas and they don't seem to make a difference. I have heard of the cam chain tensioner problem that is common of the sohc engines and i wonder if i have an early sign/stage of that problem. i don't have the knocking sound when i start my x. Also the niose seems to be the same no mader the temp outside or of the engine. Please give me some relife as to the sorce of this noise.

 

[Aussie Explorer]

If it is in-fact the timing gear you will hear it between 2500 and 3000 RPM and sometimes at idle just after the car is started, but then after the car has been running for say 3 minutes the nose will totally disappear during acceleration.

If this is in-fact what is happening it is very likely the timing gear.

My suggestion is to switch to slightly thicker oil as this will help keep the pressure on the doggy tensioner, also avoid going into that rev band for the first few minutes of driving this will help stop the chain from rattling around until the tensioner starts to function properly.

If you do all this and monitor the noise so if it gets worse I.E Makes the noise all the time when the car is started and is noticeable most of the time when accelerating/ driving then it would be a good time to look at the fix’s. First up I would talk to some mechanic’s and get prices to fix the problem so you know exactly what you are in for as it can be expensive.

 

[97FordxSport]

The thing that stumps me is that the niose happens ever time and it even happens on say a 2 hour trip from grand rapids to ludington. it does seem to be somewhat between 2500 and 3000 rpms but it doesn't go away after any amount of time of driving.

 

[CDW6212R]

Find someone who can better determine if it is pinging. If it isn't pinging, then you should start looking into the timing drive system parts. Good luck,

 

[97FordxSport]

I don't know if this matters but i filled the tank with regular unleaded today (same gas i always use) and my x didn't make the niose at all. I have noticed in the past that with a full tank of gas, usually the first 20 miles or so on the tank, i don't hear the noise.

 

[IZwack]

id umm check to make sure everythings tight first.. i mean little things such as heat shields (they often rattle and sometimes just at specific engine RPMs).

 

[97FordxSport]

thanks for the thought, but i am pretty sure its not something rattling.

 

[Aussie Explorer]

I am new tho the pinging experience; as it is not a problem down hear.

I would fill it up with good quality premium and then if it is still making the noise get a opinion about the timing gear issue from 1. A reputable mechanic and 2. Who has experience working on this motor.

If it is the timing gear is making the sound all the time then that is not good.

Remembering this engine has The main timing chain, camshaft timing chain and a balance shaft timing chain on the front and the same set-up for the back of the engine, generally it is the front camshaft chain tensioner that has the problem, but if it is the main chain tension or the gear on the back of the engine then this is a problem as it can not be fixed with the engine still in the car.

I would look at all other possibilities for the noise first, and then get a opinion on the chains.

 

[Aussie Explorer]

Sorry my mistake you have a 4*2 not 4*4 you engine does not have a balance shaft timing chain, only main and cam chains.

 

[CDW6212R]

There are four main suspect parts on the SOHC 4.0's. Those parts include the front and rear chain tensioners, and the front and rear cam chain cassettes. The rear cassette hasn't failed as often as the front, but engine removal is required to do any work on that cassette.

The valvetrain is a new design for Ford. The lifespan before maintenance is unknown. That is, manuals from the first years should be considered less reliable than current Ford knowledge. They still may always not concede that certain parts should be changed more often. It took a lot of years before manufacturers began to lower the recommended maintenance schedule for timing belts.

For peace of mind, and to avoid the very expensive repair, replace those parts sooner than recommended. Those four parts cost well under $200 total, an engine rebuild would be thousands of dollars. Good luck,