Search of posts on timing chain was negative for a method of testing for excessive wear on timing chain on this 3.8 liter Chrysler engine.

Somewhere I read that the timing chain on these engines is good for the life of the engine? Whatever that means!

Engine is running fine - no anomalies. No strange noises. Except perhaps on cold start 1st thing on a cold morning ('round 30f degrees) may occasionally be hearing the starter not retracting instantly from the ring gear. Not worried - easy replacement. (Don't want to chew up the ring gear tho. . . )

Timing chain is another matter as this is an interference engine.

Can timing chain free play be tested by pulling a spark plug and inserting a dowel or screwdriver into a cylinder and very carefully turning the crankshaft pulley a few degrees while looking for tell-tale movement of the piston? if so - clockwise or counter-clockwise?

The drawings I see in the repair manuals say it should not jump timing timing unless there's so much slack that the engine that it sounds like a threshing machine on some starts.

There's a reference to one inch total deflection between crank and cam pulleys, but that's only available when the cover has been removed.
(Absent that, one must turn the crank pulley whilst observing the result.) That 1 inch may be 3 or 4 degrees on the crank pulley?

Anyone aware of references or have experience with this as a method of evaluating timing chain wear?

 

Turning crank pulley and checking for slack at piston over TDC will only give you big end and little end clearance slack. For your cam chain you'll need to strip cover off and not only check chain for slack but also the two sprockets for hooked teeth. It has been known for the chain to jump teeth but only on the rare occasion where servicing was next to nothing. On modern engines the cam sensor would bring this up.

 

Thx goggs,

Your right - limited value for slack. There's as much slack bound upon the two sprockets as there is on free chain!

But seems worth doing even so. Simple - not much work to it. And need not be down at TDC. Right? Anywhere would do wouldn't it? Not test timing just viewing slack.

Agreed and thx- the issue of hooked teeth had not occurred to me.

Also did not know that there is a code for the timing chain. My year old INNOVA test unit likely to have that code? I don't think it can be updated as newer ones can.

jeelocked

 

Timing chain problems in these engines is quite rare although not unheard of. Usually an abused engine where its often run at high RPM is the most common course. But even a moderately cared for engine will usually be good for 200,000 miles. Something well maintain can go much further. I know of one 3.8 with over 320,000 miles on it.

However as for as I'm aware the only way to check this correctly is to remove the ******* cover and this in itself is a very involved job. However, something to be aware of is you do go ahead and have to change the timming gear is the 2005 is a change over year and so you have to determine if yours in a 2004/early 2005 or a later 2005 as they are difent and not interchangeable. Sorry I dont have the part numbers.

 

Thanks Von,

The engine has never been run hard nor run at high sustained rpms.
Regular oil changes. At about 100k I began running high mileage oils.
Never have used any synthetic oils.

Absent an OBD code or any other anomaly I'm not going to bother with the chain at this time. +

And thx for the heads-up about this being a mid year production run change.