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Discussion Starter #1
After about three months of sitting, I've finally decided to tackle a few issues with my Verde.

With the crank pulley on the P mark and the rotor pointing to the #1 spark plug, this photo I took tonight shows how the camshaft timing marks line up. I'm assuming the timing belt has skipped a tooth. The mark on the cam is 4-5 cm in front of the mark on the cam cap. This would also explain why my timing was so far advanced, right?

Michael Conrey
Smithsburg, MD
 

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You would need to open up both covers and check where both cams are sitting. I only see the picture of one, then maybe you did check both, and if they do not line up with the marks, then yes, the belt skipped. Of course you want to restore the correct timing position immediately and check your tensioner to make sure it is working correctly. Also, if you can get a hold of an inspection scope I would check the cylinders to see if the valves hit. Then again, being that it is a Milano and the engine faces forward, I would pull the heads to make sure nothing got damaged inside the engine, but that is just me. I never had a belt skip a tooth, maybe someone else can advise if this minimal skip could have caused damage, but it can be done if you provide a picture of both cams and the pulley altogether.
 

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Richard Jemison
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Cam timing

I doubt you have bent anything with the cam advanced.
You must have let the car roll backward in gear for this to happen.
If you have an "detensioner" this is common. Install a later mechanical tensioner and tighten it up so spring is totally compressed. This will eliminate this happening again.
 

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Discussion Starter #4
I did pull both covers but only took one picture since both were advanced the same amount. So if it did skip, it appears to have skipped the same amount on both cams.

This Milano already has the mechanical detensioner.

I was planning to change the timing belt and detensioner anyway since this one has almost 30,000 miles on it. I'm also thinking of pulling the right head to try and investigate an issue I've been having with premature wearing of the exhaust lobes...

Thanks for your input guys.

Michael Conrey
Smithsburg, MD
 

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if both are advanced like that, its likely that at the last belt change, it was not in proper time during assembly.

usually only the RH side skips, as its only engaged by 11 teeth on the belt (not enough IMO), whereas the LH side is engaged by more teeth.
 

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usually only the RH side skips
My belt skipped from turning the engine backwards. I am pretty sure that the crank is what slipped, leaving both cams advanced. I know that both cams were off from the crank, because the next time I tried to start the engine, I bent valves in both heads.
 

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Michael,
Just curious to know if the engine was running ok before you took the covers off. Was there any tell tale signs to lead you to check? Any problems with idling etc?
I am just trying to discover why my idling is very slightly erratic on my 3.0 V6 Verde.
I recently had a timing belt changed on my 156 GTA and now the idling is erratic - never had that problem before. The dealer that changed it reckons it's the injectors. But it was perfectly fine before the cam belt change so not sure what's happened?
 

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If you have an "detensioner" this is common. Install a later mechanical tensioner and tighten it up so spring is totally compressed.
I thought it was the other way around: hydraulic detensioner is ok, mechanical tensioner at risk of skipping if car rolled backwards.

:)
 

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Discussion Starter #9
It was running fine (although I'm having issues with cam and follower wear, but that's a seperate issue). I changed the right cam and when I started it up, it was running very bad when until the engine warmed up. I ran it this way for a week or so while I was trying to diagnose it. Then I checked the timing and found it was very advanced (like 20 degrees). I started thinking what could have caused the advance to jump and decided to check if the belt slipped and found the timing marks on the cams were not lined up properly. The last timing belt change was done at DiFatta Bros so I can't say how the marks were lined up the last time the belt was changed. I know the three or four I've done were not lined up exactly, but they were closer than this is now.

My best guess so far is that the belt jumped on the crank and advanced both cams, but I can't be sure.

Michael Conrey
Smithsburg, MD
 

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Richard Jemison
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Cam issues

No matter how used cams "look" they are worn. The wear pattern will be different engine to engine because of differences in machine setup and the minute differences in cam follower bore relationship to cam position.
That is why you must use new cam followers with any cam change.

Using multi grade oils with weights (on the cold end of the rating) less than 20 are a serious invitation to cam/cam follower failure. Flat tappet (non roller) require a heavier viscosity and additives to live . Using ZDDP additives in all current oils is a good idea.

In addition to lack of lubrication inadequate clearance will lead to early wear.

Most cam problems are not metalurgical, but from issues provided by the user!
 
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