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DOHC Timing chain broke

tarafied1

tarafied1

Well-Known Member
Some of you might recall that we built a 2005 Lincoln Aviator aluminum DOHC for the 99 GT. Well we used name brand parts. The timing set is over $300 and was a Cloyes brand. But the tensionor on the passenger head that ties the two cams together failed. The chain made some noise right before it broke. Looks like the plastic/nylon parts got chewed up and was clogging the oil pump sump screen. It had oil pressure but my son said it fluctuated. Anyway I pulled a rod cap to look at the bearings. Also cut the oil filter open. Doesn’t look like any of the plastic made it into the pump. There is some scoring on the bearing but doesn’t look fatal. I’m going to plasti-gauge then. Really disappointed in this timing chain failure though.
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Man that sucks. Look like you're destined to always have one car with an engine out.

Hopefully you can get it all back together without more issues.

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RapidRabbit said:
Man that sucks. Look like you're destined to always have one car with an engine out.

Hopefully you can get it all back together without more issues.

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yeah, it seems like I always have one torn apart!
It's really a bummer because my son put a lot of money and time in this car. He was so proud of it and it looks like a part failure, nothing he did wrong. But it's going to be expensive to fix. The Ford Performance timing set is almost $500 and gaskets and oil pump (we are going to change it just in case). Looking at close to a grand before it's all back together. Oil pump is about $100, gaskets will be close to that. Since it is such a pain we will put a new clutch in it too while it's all apart. Not going to put another Cloyes timing set in it. They are over $300 but don't trust them after this.
 
I can understand the pain and frustration but not so sure I'd blame the Cloyes chain so fast. If the stock tensioner failed that could have (likely) caused the chain path to vary and create a situation where the chain made contact as it was not designed and simply got damaged to the point of breaking. It's not like you bought a cheap brand. I venture to bet just about all of us here have run plenty of Cloyes products over the years.

Sorry this happened at all after all the hard work and effort you guys put into it. Unfortunately it happens. Just build it back better than before is the best path forward.
 
Well the stock tensionor failed simply from being worn out. The Aviator had over 200K on it. And the one that failed on the stock engine was on the drivers side crank to cam tensionor. Again the stock ones were just worn from so many miles. The Cloyes failed on the head and on the passenger side. It was the tensionor between cams that hardely has to do anything. It appears that the other one is close to failing as well. The plastic or nylon is gone on the bottom and it’s metal to metal. The rest of the set looks to be okay. Sadly enough metal went thru the engine to get imbedded in the bearings. We plasti-gauged the rods and mains. Clearance is good but bearings look bad. Crank isn’t scored though. I am pretty sure this is a Cloyes part failure. We are replacing it with Ford parts. Going to replace the bearings and the oil pump too.
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These are pics from the Aviator tear down. The chain just wore thru the tensionor arm until it made contact with the hydraulic "pusher" and the chain had enough slop to jump time. The chains and tensionors on the heads (between cams) were actually still pretty good. They are just spring loaded unlike the crank-to-head tensionors which use engine oil pressure to keep the chain tight.
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Terry I re-read your post and maybe understand you to think that the tensionor was not a Cloyes part. The timing set we installed included the chains, sprockets, tensionors and hardware. You are correct in thinking the chain failure was a result of the tensionor failure. But that was a Cloyes part and included in the set.
 
Well we put the timing set on and did a leak down test. That side failed. Pulled the head. We have bent valves.


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This is what the drivers side tensionor is supposed to look like.
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tarafied1 said:
Well we put the timing set on and did a leak down test. That side failed. Pulled the head. We have bent valves.


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Well crap. Sorry to hear that. After all the work put into that swap.



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RapidRabbit said:
Well crap. Sorry to hear that. After all the work put into that swap.



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yeah, he is pretty dejected. I have put a $1000 into already (Ford timing set, Ford oil Pump, Ford lower end bolt kit and full gasket set and renting the lift) Still need bearings and now head work. He is only part time at Advance Auto and getting ready to start school this fall. But we will get it running again, just sucks that a new part(s) failed causing all of this.
 
tarafied1 said:
yeah, he is pretty dejected. I have put a $1000 into already (Ford timing set, Ford oil Pump, Ford lower end bolt kit and full gasket set and renting the lift) Still need bearings and now head work. He is only part time at Advance Auto and getting ready to start school this fall. But we will get it running again, just sucks that a new part(s) failed causing all of this.
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We could start him a stangfix go fund me.


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yeah, I have always used Cloyes in my engines. In fact I have one in my 502, but I did have to send it back. They had made the crank sprocket wrong. I checked Summit ratings and it wasn't just me. They had a run of bad sets. Summit replaced it no arguments. I wrote it off as a fluke. Now after this, however, I don't think I will buy any Cloyes sets again.
 
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