[ncfrc]

I'm new here and I appologize if this has been discussed many times.

I just picked up the 3rd Dodge Intrepid we've owned , a 2002 ES 3.5L
with 172,000 miles.

The car is rock solid with NO rust and drives great.

The only slight negative I found when I tried it out was that for maybe a few seconds
on start up , it seems to have a low end slight rap. The car it self is in such great shape that
I bought it anyway.

I've changed the oil and only driven the car maybe a 1000 miles. It's mostly noticeable on
the first start of the day and barely there the rest of the day. I'm on the road most of the day
and it gets started a lot.

There's zero noise when accelerating from a stop light as I've heard some 3.2's with
bad rod bearings do that.

My question is ------ Should I pull the oil pan and check the rod bearings with this high
a mileage or would they make noise after it's up to temp also?

I'm leaning towards rolling a set of bearings in it just because of the mileage but then
I hate to spend a weekend on a creeper , on my back tearing it apart in the garage.

Thanks for any feedback , as it's greatly appreciated !!

I've been thru the 2.7 engine deal and had a 3.2 that I did put bearings in and sell ,
making the new owner fully aware of the scared up crank. I'm crossing my fingers
that this 3.5L engine has many more miles in it.

[Squilliam]

Could be the cold start tick. There's a TSB out for it. Redesigned rocker arms IIRC

Sent from my DROID RAZR using AutoGuide.com App

[ncfrc]

I've heard about the rocker arm update but this really sounds much deeper in
the engine. I've even tried fluttering the throttle from under the hood but can't
duplicate it. I even unplugged one coil at a time and reved it between 2 and 3 thousand
rpm's with no change in motor noise.

[peva]

There've been lots of posts over the years about people just replacing the bearings without properly machining or replacing the cranksahft, and the overwhelming majority of them turn out to be a disaster - within days or weeks of the work being done.

[ncfrc]

So you think it's a bearing starting to go ?
If so I was hoping to catch before it got worse.

You can't here it when your driving or under hard accelleration

[ncfrc]

I'm going to pull the oil pan today and see what's happening.

I picked up a set of std. rod bearings that I'll put in , hopefully the

crank is not all scared up .

[peva]

There are some people here that are much more qualified than I am to answer that. I was only responding to your indicating that you might replace the bearings with no proper crank work.

I repeat: That is almost never successful on these engines, even when there does not appear to be significant crank damage.

[ncfrc]

At this point I have no choice but to look at the rod bearings in hope that the noise is coming from somewhere else.

I appreciate your feedback , Thanks

[ncfrc]

I pulled the pan and the rod bearings looked good for the mileage.
Very little scaring on the crank journals. I reinstalled a set of std. bearings
since I was there , especially for the minor cost of $35 . The pan gasket you
have to buy anyway.

The start up noise when cold is still there so I had an A level Chrysler tech " someone who
was recommended to me " listen to the motor and his immediate response was that this
is a short skirt piston engine and that's very common. Run it and Have a good day.

One thing I'd forgotten to mention on doing this job " in the car " is when you get the pan
off and are cleaning it up , grind a 1/6" off the backside so you don't have to fight with
reinstalling it. It also helps to remove the two 6mm studs on the front of the block and replace
with 6mm bolts when bolting the pan up.

[paintballdude05]

Keep this thread updated please on how this turns out.

[cdmccul]

I wonder if anyone is close to someone at a machine shop and can ask them if it is a shorter skirt than average... The thing that I find as a problem is that if it was a case of short skirts, ALL 3.5 engines should make the same sound for the same number of hours run, IMO...

[peva]

Good question. It is a fact that the industry in general got obsessed with shortening the pistons 10 or 15 years ago, and often went too far. Piston slap was a common thing in brand new samples of several makes of cars while they were experimenting at the consumer's expense. Subaru even had a recall over it, IIRC. And noises are very common in the 3.2/3.5 LH engines at various stages of warm up/cool down cycling. Piston slap can be *very* much oil (viscosity, temperature, and age) dependent.

On the other hand, some people like short skirts.

[ncfrc]

I hear what your saying ,,,,,, Have a good Holiday !

[ncfrc]

I've done a little home work on these pistons and wish I had a picture to post.
The picture that I found of a 2002 3.5L piston really didn't have a short skirt but
it had NO side skirts at all. The wrist pin area on the piston is very narrow and
that area has zero side material all the way up to the lower oil ring land.
I wish I was better at describing it but from being into the rod bearings and seeing
a picture of the piston , it appears to me , just my opinion , that Chrysler was after
some lower rotating friction and sacrificed engine durability.
There's no reason that the rod bearings in this engine couldn't have been made .80
to .100 wider to at least fill the bearing caps but again I'm sure that on paper a narrow
bearing surface causes less drag.
Sorry, got off track , but I'm assuming for now that this less skirted piston is the noise
I'm hearing.

[peva]

Less reciprocating mass has synergistic effects: Lower forces on connecting rods and bearings, other things can be slimmed down, everything gets lighter. With lighter rotating and reciprocating parts, spinup inertia (flywheel effect) is lower, so snappier response.