cam chain guide noise

[dr pepper]

Has anyone come up with a fix for the cam chain guide noise in the 4.0 SOHC. Its in a 99 explorer . My engine sounds like a bunch of bolts rattling around in a tin can.

 

[BubbaFL]

The only fix is replace the guides, which involves stripping the engine down to the front cover to do the front, or pulling it if you need to do the rear.

If you can't do that, try STP oil treatment, and drive it until she blows.

 

[Dick Berg]

dr pepper - I replaced mine a year ago at 100k miles with a technique suggested by 2000streetrod, who is the acknowledged (in my opinion) expert in this area. I was able to replace the left side guide without the use of any special tools or alignment fixtures.
I suggest checking his many posts on the subject.
Of course, you should make sure that it's the guide. Mine was in a dozen, or so, pieces after cleaning it all out. Also suggest dropping the oil pan and oil pickup screen to remove additional broken pieces if after removing the valve cover, you can see that the guide has failed.
For reference, I have a '97 4WD, EB, 4L SOHC.
While you're in there, you might want to consider replacing the jackshaft tensioner and guide, and the hydraulic tensioner.

Good luck,
Dick

 

[BubbaFL]

2000streetrod, who is the acknowledged (in my opinion) expert in this area.

+1,000,000 . Everything I know about the 4.0 SOHC I learned from Dale (2000StreetRod).

 

[dr pepper]

dr pepper - I replaced mine a year ago at 100k miles with a technique suggested by 2000streetrod, who is the acknowledged (in my opinion) expert in this area. I was able to replace the left side guide without the use of any special tools or alignment fixtures.
I suggest checking his many posts on the subject.
Of course, you should make sure that it's the guide. Mine was in a dozen, or so, pieces after cleaning it all out. Also suggest dropping the oil pan and oil pickup screen to remove additional broken pieces if after removing the valve cover, you can see that the guide has failed.
For reference, I have a '97 4WD, EB, 4L SOHC.
While you're in there, you might want to consider replacing the jackshaft tensioner and guide, and the hydraulic tensioner.

Good luck,
Dick

Thanks for the info. Somehow I knew it wouldnt be an easy fix. BUt heres the million dollar question. Has Ford redesigned the part so as not to cause the same problem ?

 

[Dick Berg]

dr pepper - The answer is a qualified yes. As I understand it, the new parts are more robust. However, since all of the chains are constantly rubbing against the plastic guides, there will always be some wear.
As I wrote, my OEM guide lasted for 100K miles, so the new designs should hopefully last longer.
I have used Mobil1 full synthetic oil, and there was very little to any sludge build-up anywhere. I believe that the full synthetic oil provides superior lubrication, and should prolong the life af any wear components.
2000StreetRod has some great pictures that compare the new versus the old designs for the guides/cassettes.
I know for certain that the jackshaft chain tensioner was redesigned to have more leaves in the spring section.
I don't believe that you can buy only the cassette assembly from Ford, you have to buy the chain, sprockets and cassette as a set.
If you're going to only replace the cassette part, then don't use any of the new sprockets or chain. As 2000StreetRod has written, the chain and sprockets develop a wear pattern, so if the existing ones aren't damaged, then don't use the new ones unless you use all of them (chain and two sprockets).
As BubbaFL stated, you have to remove the front cover, which requires draining the coolant, removing the harmonic balancer, fan, water pump, etc. and assorted brackets.
I found it made the job a lot easier to also remove the radiator. It made removing the harmonic balancer MUCH easier.
I suggest using air tools for removing the torque-to-yield (non-reusable) bolt on the harmonic balancer and the reusable bolt on the camshaft sprocket. You should also replace the seal on the front cover where the harmonic balancer enters it.
There's a special technique for pulling the harmonic balancer, check the forum for details.
I rented/borrowed tools from local auto part stores for removing the fan and removing and installing the harmonic balancer. Although I had to improvise installing the harmonic balancer since the provided tools weren't long enough. A long metric bolt with the proper threads from ACE Hardware did the trick.

If you need any specific details, I would be glad to share my experience.

Good luck,
Dick