Anyone can tell me how to replace the spark plugs on the back side of the engine in a 2000 grand caravan? do I have to take it to the mechanic?

 

There's been a lot of discussion about this and most agree it's a pita! I have a 3.3 (the 3.8) is the same. The fronts of course are a snap. At the time, I replaced all of the rears from underneath with a collection of swivels and various extensions, In some case it is by feel only. Routing the wires can also be difficult. After I completed all of that I have done some other maintenance that gave me some more insight into alternatives. If you remove your alternator or swing it out of the way, you can get decent access to the #1 plug from above. I found that removing the wiper module as the manual recommends was not really helpful. However, I had to remove the upper intake plenum to replace a gasket and found that it opened up the rear plug area in full sight! It is an easy job to r&r the plenum, so if I ever have to do it again, that's the route I'd go. With 100k plugs, I don't think this van will need it before something big craps out
By the way, I looked at a new 2008 van and couldn't believe how access to the entire engine is dramatically improved. The rear plugs are fully accessible.

 

As stated in the manual, removing the cowl will also be helpful.

 

Raise the van and replace #3 and #5 plugs from under the van, On #1 remove the fan belt and remove the bracket that bolted the pleunm. remove the top alt bolt and loosing the lower. push alt back to the firewall and replace plug.