Overlooked - V6 SOHC External Cam Chain Tensioners

[Agis8]

Reading on this forum the last few years, I never came across anyone mentioning the external cam chain tensioners that can be replaced on the V6 SOHC engine. I have been living, since 2010, with intermittent cam chain noise (like an aluminum shredder!) at startup. Like one poster mentioned, I would restart motor and/or just wait a minute or two until the tensioners pumped up and the nose subsided. Then I typed the noise problem into YouTube and watched a video about replacing the two external tensioners mounted on the heads. Each has a spring piston, the chamber of which fills with pressurized oil to damp the chain noise. So I replaced mine and there was absolutely no noise for 3 days, then the front one sounded very bad. I guess the old tensioning system couldn't handle the new pressure. So I cleaned and reinstalled the old front one, and Voila! No noise at all. My long-endured problem was fixed. And that certainly changed my attitude toward the vehicle; from potential self-detonating time bomb (Exploder) to a possibly lasting, properly running means of transport. My Explorer has 170,000 miles on it.

Here are the part numbers:

7U3Z6K254B (for left head, front), 7U3Z-6K254-A (for right head, rear).

Rear tensioner installs through right-front wheel well (easily). Front tensioner installs after you remove the thermostat housing & throttle body (not easy but threads through hoses & wires via a long socket extension). Well worth the trouble. Available on Amazon, but worth the effort to seek out a reasonable OEM dealer on line. Got mine around $35 and $65. Small price for peace of mind and no engine removal.

Amazon (front tensioner - now it's $25 on sale!): http://www.amazon.com/Explorer-Rang...r2&keywords=cam+chain+tensioner+2000+explorer

Amazon (rear tensioner - now it's also $25 on sale!) http://www.amazon.com/Explorer-Rang...r2&keywords=cam+chain+tensioner+2000+explorer

I would strongly advise snapping those up if you think they might resolve your noise problem (could be a modestly priced gamble that could pay off). Pricing I saw a few months ago ranged from approx. $60 to $140.

NOTE: One came with a new copper sealing ring, the other didn't; so don't discard the old ones. After torquing to spec with used sealing ring, my right rear one leaked some; so I torqued to an extra 15 ft-lbs. Worked fine then. (Spec. on torque was 44 ft-lb for each, as I remember -- approx.--)

 

[2000StreetRod]

try the search button

Reading on this forum the last few years, I never came across anyone mentioning the external cam chain tensioners that can be replaced on the V6 SOHC engine. . . .

I did a search of the forum on "hydraulic tensioner" and there were 215 threads that mention it. New hydraulic tensioners can't fix chain rattle due to broken cassette guides. Also, members have found that the springs in many of the newer hydraulic tensioners are weaker than their original ones having more than 150 K miles. The first step in Ford's repair procedure for timing chain rattle is to replace the hydraulic tensioner(s). That's because it's relatively cheap and easy compared to replacing a cassette.

I'm glad that replacing your tensioners fixed your rattle problem but I think you were lucky.

 

[Mike65]

Our 99 Sport w/82K miles had the rattle on cold start up & I replace the rear tensioner & now I have almost no noise on cold start up. I have not replaced the front one yet. The ones I bought were made by Cloyes & the part #'s are 95586 for the right upper $33.99, & 95587 for the left upper $39.79. I got them from Rockauto.

 

[2000StreetRod]

made in Taiwan

The timing chain components sold by Amazon linked in the first post are from Inner Fire Engine Parts in California who is a distributor for their products made in Taiwan. I would choose the Cloyes components from Rock Auto for possible greater quality and reliability.

 

[Agis8]

Thanks 2K,

After unknowingly buying a car with that big problem, I think I wasn't undeserving of a little luck later.

I did a search of the forum on "hydraulic tensioner" and there were 215 threads that mention it. New hydraulic tensioners can't fix chain rattle due to broken cassette guides. Also, members have found that the springs in many of the newer hydraulic tensioners are weaker than their original ones having more than 150 K miles. The first step in Ford's repair procedure for timing chain rattle is to replace the hydraulic tensioner(s). That's because it's relatively cheap and easy compared to replacing a cassette.

I'm glad that replacing your tensioners fixed your rattle problem but I think you were lucky.