Rattle noise at startup, 2000-3000rpm acceleration on '06 4.0L SOHC Explorer

[JoshuaK]

2006 Ford Explorer 4.0L V6 SOHC with 165,000 miles. Have had a rattle occurring during startup over the last few months. More noticeable at 2000-3000 RPM. Stops when engine is warmed up. No other noises. Have read about SOHC timing chains. It isn't continuous like some have suggested with broken timing chains. Some posts have suggested the timing chain tensioners not being tight and allowing the chain to rattle.

Should I replace just the timing tensioners or does the entire timing chain need overhaul?

Any help would be appreciated. Would like to keep cost down and not swap everything.

 

[chefduane]

Pull your oil pan and see if there are any loose plastic parts in the pan. If there are, then most likely you do have cassette damage and there is nothing you can do short of pulling the engine and the fixing the chain guides. Do both front and rear if you do decide to pull the engine. If you do not have any plastic parts, the you could try replacing the tensioners and hope for the best. Mind you that sometimes replacing the tensioners places stress on the already compromised cassette guides that might cause the guides to then fail. It's kind of a catch-22. When I found plastic cassette parts in the pan of my '98 I made the decision to not replace the tensioners nor pull and fix the guides. On a almost 20 year old vehicle with 210k miles, its simply not worth the cost (probably $2-3k). What I did do was to change to a full synthetic oil with a premium quality filter, The noise has abated and the engine really runs great. (I've done a lot of other stuff prior to the damage.) I'll just drive her till she goes kaput, whenever that is. Your decision as to how you proceed. Good Luck.

 

[JoshuaK]

Pull your oil pan and see if there are any loose plastic parts in the pan. If there are, then most likely you do have cassette damage and there is nothing you can do short of pulling the engine and the fixing the chain guides. Do both front and rear if you do decide to pull the engine. If you do not have any plastic parts, the you could try replacing the tensioners and hope for the best. Mind you that sometimes replacing the tensioners places stress on the already compromised cassette guides that might cause the guides to then fail. It's kind of a catch-22. When I found plastic cassette parts in the pan of my '98 I made the decision to not replace the tensioners nor pull and fix the guides. On a almost 20 year old vehicle with 210k miles, its simply not worth the cost (probably $2-3k). What I did do was to change to a full synthetic oil with a premium quality filter, The noise has abated and the engine really runs great. (I've done a lot of other stuff prior to the damage.) I'll just drive her till she goes kaput, whenever that is. Your decision as to how you proceed. Good Luck.

I have used synthetic oil in the car for the whole life of the car. Dropping the oil pan would require a new gasket, correct? Is it just removing all the bolts that attached the pan to the engine. Would I need to drain the oil first? Wouldn't plastic pieces come out of the oil pan during a drain? I have seen some videos on these tensioners and feel like they have just lost some of their spring and thus not keeping the timing chain tight, causing the rattle?? Thanks for the response.

 

[Tech By Trade]

Congratulations on your short term future purchase of a new to you engine!

 

[chefduane]

I have used synthetic oil in the car for the whole life of the car. Dropping the oil pan would require a new gasket, correct?

---> Yes, I would put on a new gasket.

Is it just removing all the bolts that attached the pan to the engine. Would I need to drain the oil first?

---> Yes, and yes.

Wouldn't plastic pieces come out of the oil pan during a drain?

---> Depending upon the size of the pieces, maybe. Dropping the pan would be the only way to remove oversize pieces.


I have seen some videos on these tensioners and feel like they have just lost some of their spring and thus not keeping the timing chain tight, causing the rattle??

---> Yes, but the tensioner actually lays against the chain guide cassette that holds the chain in place. Depending upon how had the cassette has broken up, a new tensioner won't do a thing. And it may actually cause the remaining cassette pieces to break off and cause additional damage.

Thanks for the response.

---> No problem. Unfortunately, short of pulling the engine and doing a complete timing chain job (as mentioned above) there is not a lot you can do.

(I put some of my responses within the body of your post. Expand it to see the compete text.)

 

[chefduane]

Congratulations on your short term future purchase of a new to you engine!

Or he may decide to just drive it till she dies. So far I have 13k miles on my SOHC since I first found guide pieces in my pan. At 210k miles there is no way I can see myself pulling the engine and doing a timing chain job. I'll just keep driving it until she decides enough is enough. But at 210k miles, a couple times across the country through rain, snow, sleet, 120 degrees in Death Valley, and outrunning a tornado outside of Memphis, I have no complaints. My SOHC has outlasted a lot of 5.0's.