Timing Chain question

[scott98922]

Hey guys, I'm new here and I own a 2004 ford Explorer Sport Trac 4.0L SOHC, been a great truck until recently.

I was on my way to work, and I stopped and seen smoke coming from under the hood, after checking what was going on I seen on the front driver side valve cover was a hole, about 2" tall and a 1/2" wide in my valve cover, truck was still running fine with no noise. So I limped to my work, less than a half a mile away, covered the hole with some jb weld putty and let it sit. The next day I fired it up and there is a slapping going on, kinda sounds like my timing chain, could a bad tensioner cause that much slack on that side to cause that?, or is it a guide?

The timing chains and tensioners and all were replaced in January by a local shop at the fine tune of $3,000. I am hoping this is a simple fix of maybe a faulty part. Any help on this would be appreciated, Thanks !!

 

[Tech By Trade]

Sounds like a botched job if the chain popped through the valve cover. i would be going back to that shop.

 

[scott98922]

The truck is at their shop now I am just trying to figure out what could have caused it. Myself I think it is a guide but they are saying a the tensioner went out.

 

[2000StreetRod]

broken cassette

I disagree with the shop's diagnosis. Those are the symptoms of a broken front cassette. I doubt a failed hydraulic tensioner would allow enough slack in the chain for it to strike the valve cover. Did the shop use OEM parts or something cheap purchased via eBay?

 

[scott98922]

From what the invoice said it was OEM parts, but the technician that done the work is no longer with the shop, so very possible it was just shady work.

 

[2000StreetRod]

head pulled?

Was the head pulled before installing the cassette guide? Ford changed the head and/or block castings around 2004 making it almost impossible to replace the cassette guide without removing the head. The pivot pin is longer than the clearance. Some try to pound the guide into position which usually damages the pivot pin or fractures the guide. I doubt the shop procedure for the 2004 reflected the change requiring removal of the head. The newer cassette guides are held together with a removable pivot pin allowing replacement of the guide without removing the head but its a pain to install the pin and keeper after the guide has been positioned in the block.

Old:

New:

My guess is that the shop technician was not familiar with the change and forced the guide into position and damaged it.

 

[scott98922]

Yes 2000StreetRod, i failed to mention in my original post that the truck originaly went in with a failed head gasket on driver side, i was charged for timing chains being changed as well, so no telling whats up with it, i know this truck has drove me insane lol.