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99 Grand Voyager 3.3. to 3.8 swap

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Wow... I've been a member here since 2005... Whoa! Wait... I thought it was longer than that... back to the late 90's.... Anyway...

I was given a 1999 Plymouth Grand Voyager. Really nice van... body and paint are great, interior is okay... one problem... okay, two... The transmission and engine... The tranny is shot. Planetary set imploded. The trans is being rebuilt as we speak. (Well, tomorrow anyway).

The motor... It has the 3.3 V6. Spun a rod bearing. Went to the local pull-a-part and the only motor that we could find in a wrecked van was a 3.8. The price was right, so we nabbed it, along the the PCM, The motor and PCM came out of a 1998 van.

When I dropped the tranny off to the shop, we were telling him about the 3.3 to 3.8 swap. He was saying that the 3.8 PCM might not like the 3.3 trans. Something about gear ratio errors and gearsets.

So... will I be able to run the 3.8 motor with the 3.3 trans using the 3.8 PCM, or do I need to use the 3.3 motor, 3.3 trans, and 3.3 PCM?

I'm faced with a couple of choices...

1> Rebuild the 3.3 in there now - It is going to need machine work, plus parts... Prolly around $2000+

2> Drop the 3.8 in and hope for the best. It was a running motor when it was pulled. We took the oil pan and rocker covers off to inspect it and the motor is fairly clean inside.

3> Buy a remanufactured 3.3 - 3 yr/unlimited mileage warranty, plus it will be the right motor, and no issues. $1700 or so...
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· Registered
41 Posts
The 3.3L tranny has a lower final drive gear ratio so hooking a 3.8L to it will make the van somewhat of a hot rod over what it was before. Should be fun! Use the 3.8L PCM but make sure that it will match your BCM if your van doesn't have anti-theft as the anti-theft system is shared between the two AFAIK & you can have problems if an anti-theft equiped PCM or BCM is installed in a non-equiped van.
Should smoke the right front tire real good. Might want to make sure that the differential pin is secured with the latest fix. Just my $0.02.


· Registered
9 Posts
Discussion Starter · #4 ·
I ended up just buying a reman'd 3.3 for the van. I'm building it for my mother, to replace her older 94 Caravan. I need it to be reliable and trouble free.

Maybe I will just sell the 3.8 to recoup some of the money spent on the 3.3......

· Registered
1,147 Posts
The Electron said:
What do y'all know about problems when using 2nd gen engines in 3rd gen vans, and vice versa?
The 3rd Gen minivans were OBDII compliant and a few changes took place. The basic long block should work, but sensors and electronics will be different. The 3.0 probably had the bigest changes in 1996 when they replaced the opical distributor with a Hall-Effect unit and added a flex plate with timing slots and a crank position sensor on the transmission bell housing.
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