Dodge Grand Caravan 1999 - 3.8L low compression on one cylinder

That vintage of Caravan, in my humble opinion, was one of the best. The front seats were so comfortable. I really liked the 1997 that my parents had that I learned to drive on. It was great for trips too. Transmission was a little fragile, but overall a great car.
 
That vintage of Caravan, in my humble opinion, was one of the best. The front seats were so comfortable. I really liked the 1997 that my parents had that I learned to drive on. It was great for trips too. Transmission was a little fragile, but overall a great car.

Thanks CT.
I would have to agree.
With over 300,000 trouble free miles now (original engine, original trans, 60psi oil pressure), I'm more than happy.

She literally Glides along with a better ride than many newer luxury cars, quiet as a whisper at highway speeds, comfortable for LONG road trips.

3rd Gen Dodge minivans (imo) had the best of the modern updates (styling and features) but still had most of the quality of the older gen vans.

Once fiat bought Chrysler going into Gen 4, it was game over imo.
Then again, we've seen an across the board decline in vehicle quality since then. It wasn't only Dodge/Chrysler.
 
So did you get the measurement on that?

Not yet. But I can probably get to it today.
I DID measure the crankshaft rod journals earlier tho with my mitutoyo caliper I recently bought because the Harbor fright ones just didnt have the accuracy.

2.2835 Perfect.

So I'm somewhat expecting the barrels to be ok as well, but we'll see.

I'm just doing so many other things. In the process of repairing and painting the rear hatch on one of 1999's....had to put shelving back up that fell down in my shed, cutting grass, huney Dews, etc etc etc
 
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Love the hard work on the van, OP.

I've got a soft spot for anything Mopar van. I grew up with two: a fire engine red-on-red 2nd gen Voyager that had 3 options: the 3.0 Mitsu/3-speed auto combo, power door locks, and a cassette radio. My parents bought it brand new in 1993. The transmission failed in spectacular fashion on the way to my freshman orientation.

That van was replaced by a '97 Town & Country LXi my folks picked up with 60k miles on it, somewhere around 2003. Compared to the first van, it might as well have been a Bentley. Mom kept that thing around until almost 200k when we finally retired it for something smaller.
 
Love the hard work on the van, OP.

I've got a soft spot for anything Mopar van. I grew up with two: a fire engine red-on-red 2nd gen Voyager that had 3 options: the 3.0 Mitsu/3-speed auto combo, power door locks, and a cassette radio. My parents bought it brand new in 1993. The transmission failed in spectacular fashion on the way to my freshman orientation.

That van was replaced by a '97 Town & Country LXi my folks picked up with 60k miles on it, somewhere around 2003. Compared to the first van, it might as well have been a Bentley. Mom kept that thing around until almost 200k when we finally retired it for something smaller.

Love to hear stories like this. I'm sure you have many memories of places you went and things you did using that '97.
Bentley? Hey, don't insult the Gen 3 Caravans :)

I plan to keep all my Gen 3's running and as close to new condition as possible. No plans whatsoever to ever get rid of them or get any of those new vehicles that are not worth it imo. But to do that without a winning lotto ticket I'd better be able to do everything necessary on my own.
 
So did you get the measurement on that?
Yes I did.
So I painstakingly took measurements at the Top of the bore, front to back, the middle of the bore front to back and bottom front to back. Of course, the skirts are front to back so the thrust and skirt wear is mainly against the front and back of the bore. No?
This is not the easiest measurement process in a motor. With the tools I have I have to be very careful about getting the cylinder bore gauge properly squared and straight in the bore. Takes some patience and I took the readings multiple times to confirm.

So, without further adoo........

Top of Bore (Front to Back)
3.779

Half way down the bore (front to back)
3.778

1 inch from Bottom of the barrel (front to back)
3.7775

And the Standard Bore for the 3.8 is 3.779

So what's your verdict? I'm pretty sure I have a good motor here. What say you?

Working hard to get that bore gauge square in the cyl.
IMG_20250424_165851804_HDR_Smaller.webp


I did all 3 measurements multiple times. The bore gauge seems off juuuuust slightly in this photo.
IMG_20250424_171626116_smaller.webp


Some of my Micrometers. These are my absolute favs. Vintage NSK. I bought these in the early 80's.
IMG_20250424_170134936_smaller.webp


Oops. I dropped the bore gauge through the bottom of the cylinder. It's a lot harder to fish it out that it appears.
IMG_20250424_165155186_HDR_smaller.webp



FSM Specs for the bore in question. I didn't look at these until after I was finished. Then I just smiled.

3.8_Cyl2_Measurements_04-24-2025-1.webp
 
Hone it ring it and send it then?

At this moment, that's the plan. First, I had to press out the wrist pin from the old rod, and I'm researching to make sure I know how to successfully reinstall the wrist pin into the new piston without damaging or bending anything.

From what I gather, heating the rod end with a torch and putting the wrist pin in the freezer makes it go easier.
 
At this moment, that's the plan. First, I had to press out the wrist pin from the old rod, and I'm researching to make sure I know how to successfully reinstall the wrist pin into the new piston without damaging or bending anything.

From what I gather, heating the rod end with a torch and putting the wrist pin in the freezer makes it go easier.
Or in an oven.
 
Thing is, you have what......000000001 seconds to get it centered before the rod contacts and the wrist pin expands?

What do you do if the pin will no longer move but is not centered? Use your press?
 
At this moment, that's the plan. First, I had to press out the wrist pin from the old rod, and I'm researching to make sure I know how to successfully reinstall the wrist pin into the new piston without damaging or bending anything.

From what I gather, heating the rod end with a torch and putting the wrist pin in the freezer makes it go easier.
Why? Why not simply soak in cleaner to dissolve any carbon and re-ring. Then assemble.
 
Engine Builder Alert

If you work on engines this might be of use to you....
While installing the cylinder head ONE of the head bolts yielded BEFORE the specified torque was reached.

I was following the Torque To Yield process and 7 of the bolts torqued just fine. The process called for torquing to 45fl bs in sequence, followed by a re-torquing at that same torque, followed by torquing to 65ft lbs. it was on this 65ft lb round that I felt a sudden give in the torque wrench and I knew exactly what had happened. That one bold yielded at only 65ft lbs, WELL below the factory requirement of at least 122ft lbs after the final 1/4 turn.

The product is

MAHLE GS33360 Engine Cylinder Head Bolt Set, 1 Pack​

Sold on Amazon

There is obviously a QC issue. Just be aware if you use MAHLE head bolts.
 
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Engine Builder Alert

If you work on engines this might be of use to you....
While installing the cylinder head ONE of the head bolts yielded BEFORE the specified torque was reached.

I was following the Torque To Yield process and 7 of the bolts torqued just fine. The process called for torquing to 45fl bs in sequence, followed by a re-torquing at that same torque, followed by torquing to 65ft lbs. it was on this 65ft lb round that I felt a sudden give in the torque wrench and I knew exactly what had happened. That one bold yielded at only 65ft lbs, WELL below the factory requirement of at least 122ft lbs after the final 1/4 turn.

The product is

MAHLE GS33360 Engine Cylinder Head Bolt Set, 1 Pack​

Sold on Amazon

There is obviously a QC issue. Just be aware if you use MAHLE head bolts.
Did you take it out to inspect? I'd certainly be more suspect of threads in the block than a bolt failing at 65#
 
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