My customer burned all his luck with his car for the next three years

Car was running when it came in. I had to do a valve cover gasket and the customer asked I look into why his timing chain was making more noise then usual. It had been rattling for about 5 months now he said. I noticed that there was something not quite right with his timing chain guide and pulled out a couple of plastic pieces. Then called him and told him the engine timing components needed to all come out. This is what is left of his timing chain guides. The pieces on the right are what I found INSIDE his oil pump chain housing.

The vehicle is a Mini Cooper S.

http://i3.photobucket.com/albums/y69...ps24fc54bc.jpg

is that all plastic? (except for that gear thingy)

Most of the guide is plastic. You can see in he top right of the left paper towel a metal part and in the right towel a metal part. Those are part of what the plastic mounts too. Doesn't matter though. A piece of metal could make the chain jump but a piece of plastic could clog an oil passage. The metal is chewed up too. So the chain was rubbing on both.

Is this common in Coopers?

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Originally Posted by 3beansalad

Is this common in Coopers?

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Don't know. I know they had a tensioner issue for this year that would cause a rattle. Haven't heard of this happening before. Even Googler it to see if the forums had seen anything on it and nothing.

Why was the timing chain loose? Tensioner? Wear?

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Originally Posted by newracer

Why was the timing chain loose? Tensioner? Wear?

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When I pulled the valve cover off the chain was not lose. The tensioner was nice and tight. The part that failed was the guide between the two cam gears. Looks like it broke off and dropped into the rest of the timing components. These do have a TSB/Recall for the timing chain tensioner so it is possible that the chain tensioner failed but tightened up again. But I don't buy it. I think it was a failure of the top chain guide that set the whole thing in motion.

I just assumed the chain was loose and hitting the guide causing the failure, especially since it was making noise.

He is very lucky!

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Originally Posted by newracer

I just assumed the chain was loose and hitting the guide causing the failure, especially since it was making noise.

He is very lucky!

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The noise was from the chain running over and rubbing against the pieces that had fallen in the V over the the crank shaft gear.

I think I know what happened.

There is that recall for the chain tensioner on this engine. The procedure is just to swap the tensioners and not really look at what is going on internally. So that is what happened, but by that time the chain was probably flopping around and it had beat up the upper guide but not broken it. The tech replaced the tensioner listened to the engine and shipped it because the noise was gone. Fast forward a few years and the guide finally says fuck this and falls apart. 8 months later I get it.

Hydraulic tensioner?

Too many burnouts.


Lucky mofo, bent valves and holed pistons were a mere heartbeat away.

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Originally Posted by JMBD2112

Hydraulic tensioner?

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Yup

you said it was a Mini..... was it airborneranger's?

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Originally Posted by BPTactical

Too many burnouts.


Lucky mofo, bent valves and holed pistons were a mere heartbeat away.

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No doubt....5 months too., damn lucky.

I'd brought to my shop the minute I heard those noises.

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Originally Posted by TheBelly

you said it was a Mini..... was it airborneranger's?

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Nope.

Or at least he has not identified himself as such.

And will be very careful not to ...

You think and hammer can fix that?

Ya know way back when GM tried the nylon on metal timing chain gears to make them better. Many warranty claims later they thought better of this.

Heat, chemicals and plastic are no way to build an engine. Some things they have figured out but at the cost of failed parts/engines to start with.

not good. hard to believe they used plastic there. not smart

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Originally Posted by sniper7

not good. hard to believe they used plastic there. not smart

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Motorcycles have been using poly cam chain tensioner guides for as long as I can remember ( early 80's honda's and newer )

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Originally Posted by sniper7

not good. hard to believe they used plastic there. not smart

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You'd be really surprised, even your truck has a plastic timing chain shoe/ tensioner.

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Originally Posted by JMBD2112

You'd be really surprised, even your truck has a plastic timing chain shoe/ tensioner.

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thats why I trade them in every year! always under warranty!

Attachment 32037

GM was having problems with timing chains actually stretching in the 3.6, this one was in a new body Malibu. Notice that all the shoes are plastic

Edit: for some damn reason it posted the pic upside down, sorry about that

Is that an interference engine?

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Originally Posted by sniper7

thats why I trade them in every year! always under warranty!

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I've only seen one tensioner break on a 5.3, and it broke when I was collapsing to do a cam swap. Never seen one actually fail

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Originally Posted by JMBD2112

I've only seen one tensioner break on a 5.3, and it broke when I was collapsing to do a cam swap. Never seen one actually fail

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Mini had a recall on them. And I have seen it in VAG. But typically it is due to incorrect engine oil used or infrequent oil changes. Sludge build up, clogged passages will lead to tensioner failure.

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Originally Posted by tmleadr03

Mini had a recall on them. And I have seen it in VAG. But typically it is due to incorrect engine oil used or infrequent oil changes. Sludge build up, clogged passages will lead to tensioner failure.

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GM had the bright idea that they could push oil change intervals out to 10k, after they started seeing all the problems it was causing, they came out with a PCM reflash to bring down to 7500.....[facepalm]
I even had a few that the chains were so stretched the cam actuators would take the slack completely out of the chain and the motor couldn't advance or retard the timing on accel / deccel. The actuators are supposed to have total movement of 25 degrees if that puts it into perspective.