Ford Timing Chain Tensioner Cutaway

[Olds67]

No I unplug the crank sensor and prime with the starter

Alright where is the sensor? If i may ask. Newbie
Would you change only the tensioners on a 150k gen2 sohc if it has -on document- been serviced well by ford dealership for the last 20 years but has just a slight rattle in neutral. Or better dont change the running system, leave it and wait till it gets worse and then change everything (the notorious big job)
Can i just remove the tensioners and check if they have to be replaced. Is that worth it?
That whole death rattle panic on the Internet makes me paranoid. Just bougt the car and love it. Drives great. Wouldn’t have noticed the slight rattle if hadnt heard of it before...

 

[donalds]

If it is rattling at all any time something is broken.
Usually startup rattle
And or
a rattle at 1500-3000 rpm
The best way to check your timing components
1 pull off the lower oil pan look for plastic pieces
2. Pull the valve covers and see everything

 

[Olds67]

If it is rattling at all any time something is broken.
Usually startup rattle
And or
a rattle at 1500-3000 rpm
The best way to check your timing components
1 pull off the lower oil pan look for plastic pieces
2. Pull the valve covers and see everything

Will do! Thanks
Like i said, i wouldn’t have noticed it if i hadnt heard about it before. An engine makes noise - especially on with 3-4 frickin chains. Any honda motor i‘ve owned was louder. But i will check top and bottom as you mentioned.

 

[CDW6212R]

The two external tensioners can be changed at any time and it can help the chains to be tighter than if they had any wear from age etc. There are many parts of the cam timing system, the internal tensioners and the chain cassettes are also fragile and can use extra maintenance after many years. Those are the ones that take a bunch more labor, and the special tool kit to re-time the cams after parts are loosened.

The external tensioners are not expensive, even the OEM are reasonable(don't buy the lesser brands), and I'd try to replace those every 75k miles. Use the best synthetic oil you can, and don't let it go over 5k miles before changing it. Change the air filter regularly, don't let one get dirty which hurts the oil(don't buy K&N filters). That's the best care you can give the SOHC 4.0, those well cared for can go way over 200k without rebuilding.

 

[Olds67]

The two external tensioners can be changed at any time and it can help the chains to be tighter than if they had any wear from age etc. There are many parts of the cam timing system, the internal tensioners and the chain cassettes are also fragile and can use extra maintenance after many years. Those are the ones that take a bunch more labor, and the special tool kit to re-time the cams after parts are loosened.

The external tensioners are not expensive, even the OEM are reasonable(don't buy the lesser brands), and I'd try to replace those every 75k miles. Use the best synthetic oil you can, and don't let it go over 5k miles before changing it. Change the air filter regularly, don't let one get dirty which hurts the oil(don't buy K&N filters). That's the best care you can give the SOHC 4.0, those well cared for can go way over 200k without rebuilding.

Thanks for the advice! I just put in the order for the mentioned parts.

 

[CDW6212R]

I bought my last pair of the OEM tensioners from eBay I think, about $75 for the front one and a little less for the rear part. Those should include the tiny crush washer, but be sure to use the washer, they will leak without it, or if it gets put on off center. Just put a dab of RTV on the washer surface to hold it briefly while you thread it on.

 

[Olds67]

I bought my last pair of the OEM tensioners from eBay I think, about $75 for the front one and a little less for the rear part. Those should include the tiny crush washer, but be sure to use the washer, they will leak without it, or if it gets put on off center. Just put a dab of RTV on the washer surface to hold it briefly while you thread it on.

Mh okay... i ordered these

Hope these are the right ones. Seems to be a price drop
Good day

 

[donalds]

Cloyes is 3nd best

melling being 2nd made in America

Your order is fine
Will work great

 

[CDW6212R]

I didn't search but one time online, but this link was one of the top choices. The OEM Ford tensioners are more but they are the best among the choices. Some bad brands have both of these for under $30 total shipped, those I would call crap.

Here's the Ford parts, two for $113 plus tax; BRAND NEW FORD MERCURY OEM TIMING BELT TENSIONER 4.0L V6 12V SOHC COMBO SET-4 | eBay
Be sure what you buy includes the crush washers, they are very important. Try to save the old washers just in case; they are reusable if you are careful with them.

 

[BTR]

2000 Explorer XLT 2WD 4.0L SOHC, JOB 1, VIN E, 5-Speed Automatic O/D 5R55E, Manufactured 09/99.

@donalds - Do you mind if I ask you about the timing chain tensioners? Specifically, 7U3Z-6K254-A (Right) and 7U3Z-6K254-B (Left). I'd like to understand if I... should... or shouldn't... replace mine.

Assume the following:

• I don't have the ability to drop the oil pan nor remove the valve covers. Thus, I cannot perform diagnostics that require the removal of these parts.
• My engine (4.0L SOHC) has 145,000 miles on it. In the past, sometimes it's had good care vis a vis oil changes... sometimes not.
• My engine rattles on startup. However, I cannot discern/describe what type of rattle it is.

Given the assumptions above, I don't know which parts of the "timing chain system" are, or aren't, broken/stuck/stiff/etc. Based on this, should I replace the 2 timing chain tensioners?

Please advise. Many thanks!

 

[donalds]

I'd replace them IF
the rattle only lasted about 1sec
If that's the only rattle
Is there a rattle example under load at say 2000- 3500 ??

Buy only only only motorcraft tensioners

Ford Timing Chain Tensioner Cutaway

Thought I'd post this. Thought it'd help someone. Any thoughts?

www.explorerforum.com

 

[BTR]

@donalds - Thank you. I always appreciate your insights.

 

[Flashflood]

2000 Explorer XLT 2WD 4.0L SOHC, JOB 1, VIN E, 5-Speed Automatic O/D 5R55E, Manufactured 09/99.

@donalds - Do you mind if I ask you about the timing chain tensioners? Specifically, 7U3Z-6K254-A (Right) and 7U3Z-6K254-B (Left). I'd like to understand if I... should... or shouldn't... replace mine.

Assume the following:

• I don't have the ability to drop the oil pan nor remove the valve covers. Thus, I cannot perform diagnostics that require the removal of these parts.
• My engine (4.0L SOHC) has 145,000 miles on it. In the past, sometimes it's had good care vis a vis oil changes... sometimes not.
• My engine rattles on startup. However, I cannot discern/describe what type of rattle it is.

Given the assumptions above, I don't know which parts of the "timing chain system" are, or aren't, broken/stuck/stiff/etc. Based on this, should I replace the 2 timing chain tensioners?

Please advise. Many thanks!

I would replace them there not that hard to replace. Sneak by the passenger tire and you can get the back one. The front one my have to drain the rad a little bit but otherwise . Unfortunately it's all cold and snowy here so really can't do mine so I just got in a box !

 

[Olds67]

@donalds - Thank you. I always appreciate your insights.

Respectfully, in my opinion, just use the WOT technique for cold starts and then see what it does for you. Cold starts (and old oil) are the real threat to the plastic guides if they’re not already shot.

If you want to change the front tensioner, you can also remove/clean the valve cover on that side, it’s not that many more steps, since you had to remove the upper intake (with gaskets) anyways. With these many miles it’s a good idea, it did wonders for mine. Definitely more work than dropping the lower oil pan, so not sure if you’re willing to.

I’m a newbie, but that’s the experience i made after this procedure, so i thought I’d share.

 

[BTR]

Respectfully, in my opinion, just use the WOT technique for cold starts and then see what it does for you. Cold starts (and old oil) are the real threat to the plastic guides if they’re not already shot.

If you want to change the front tensioner, you can also remove/clean the valve cover on that side, it’s not that many more steps, since you had to remove the upper intake (with gaskets) anyways. With these many miles it’s a good idea, it did wonders for mine. Definitely more work than dropping the lower oil pan, so not sure if you’re willing to.

@Olds67 - Apologies for being obtuse, but can you clarify? I want to make sure I understand. Thanks.

Are you saying that pushing the accelerator all the way to full throttle (and holding it there) will allow the engine to be cranked without it starting... yes... no? If yes, then are you saying that cranking an un-starting engine will allow oil to be pumped throughout the engine (including to the timing chain tensioners)? If so, in order to adequately lubricate the engine, how long should I crank the engine at WOT?

What "did wonders" for your engine... replacing the timing chain tensioners... cleaning the valve cover... or both?

Please advise. Thanks.

 

[donalds]

Try the whole full throttle thing did not work on mine
I had to hold the break to

Crank till the gauge shows oil pressure

New tensioners will only help with the noise if your guides are good in most cases

 

[CDW6212R]

Try the whole full throttle thing did not work on mine
I had to hold the break to

Crank till the gauge shows oil pressure

New tensioners will only help with the noise if your guides are good in most cases

Ditto, the SOHC has several timing chain problems, the external tensioners are the minor one, and easy to replace. That's why most conversations discuss those at long length, and people just do those and hope for the best with the rest.

The internal tensioner(two for a balance shaft engine) is a fragile design, and the plastic guides which the chains ride against, are wear items. A loose chain(the noise at any time) will wear the plastic guide parts out much faster.

With a SOHC in fine condition, simply providing excellent oil and oil pressure can make the engines last a long time. But once the chain rattle begins, you are on borrowed time with the plastic guides. So pay close attention to the engine sounds of a SOCH 4.0, listen for any rattling sounds at any time.

 

[Olds67]

@Olds67 - Apologies for being obtuse, but can you clarify? I want to make sure I understand. Thanks.

Are you saying that pushing the accelerator all the way to full throttle (and holding it there) will allow the engine to be cranked without it starting... yes... no? If yes, then are you saying that cranking an un-starting engine will allow oil to be pumped throughout the engine (including to the timing chain tensioners)? If so, in order to adequately lubricate the engine, how long should I crank the engine at WOT?

What "did wonders" for your engine... replacing the timing chain tensioners... cleaning the valve cover... or both?

Please advise. Thanks.

Yes, WideOpenThrottle lets the engine crank but cuts fuel thus not start. I was surprised too when i heard it first, because i was used exactly the opposite from old carburetor cars it’s time to let off the pedal quickly when you see the oil pressure or/and yellow 4x4 lights etc on the right of your dash flashing.
When the engine is hot, the engine doesn’t seem to like WOT very much. So after a really quick gas stop i dont do it. After a longer wait i still crank it 1-2 seconds just to make sure the pressure is up.

Sorry for not being clearer.
The whole valve removal procedure did wonders, because at the same time you will be able to change the intake manifold gaskets, check hoses for vacuum leaks, change pcv valve, air filter of course, clean throttle flap if necessary, change valve cover gaskets (i used the highest recommended torque and still gave it a little snug), clean out all the gunk inside the valve covers. The tensioners wont do anything for drivability. It’s just something you can do, but it wont save a highmilage engine alone

 

[Flashflood]

Yes, WideOpenThrottle lets the engine crank but cuts fuel thus not start. I was surprised too when i heard it first, because i was used exactly the opposite from old carburetor cars it’s time to let off the pedal quickly when you see the oil pressure or/and yellow 4x4 lights etc on the right of your dash flashing.
When the engine is hot, the engine doesn’t seem to like WOT very much. So after a really quick gas stop i dont do it. After a longer wait i still crank it 1-2 seconds just to make sure the pressure is up.

Sorry for not being clearer.
The whole valve removal procedure did wonders, because at the same time you will be able to change the intake manifold gaskets, check hoses for vacuum leaks, change pcv valve, air filter of course, clean throttle flap if necessary, change valve cover gaskets (i used the highest recommended torque and still gave it a little snug), clean out all the gunk inside the valve covers. The tensioners wont do anything for drivability. It’s just something you can do, but it wont save a highmilage engine alone

God I don't do mine that long. I do it for maybe 3 to 5 and works fine

 

[Olds67]

God I don't do mine that long. I do it for maybe 3 to 5 and works fine
what your gut tells you, is right 4-5 is about the times my dash reacts and the engine starts so smoothly afterwards.
Man i remember when i bought the car and didn’t know about wot. It felt like an exploder for real.