2.5 swapability

[mfpdm]

Well checking the oil today in the 86 was depressing. I found the white foam under the cap. :fs1: Oil has a faint smell of gas so I'm thinking it has a bad head gasket or a crack some place. Anyhow, I have the 2.5 that came out of the 88. I'm thinking, if the 86's 2.5 goes, swapping in the 88's. Plan will be pulling the 2.5 with 5spd out and putting the 2.5 with 4spd in. Is this a direct swap or are there differences between the two ie wiring, sensors, or what not?

 

:cheers:

[Eagle]

86 and 88 were both Renix-based, throttle body injection. They should be pretty much interchangeable as far as I know.

 

Just watch out for water pump issues. If one has a serpentine belt and the other has conventional vee belts, the rotation of the water pumps will be reversed.

[mfpdm]

86 and 88 were both Renix-based, throtle body injection. They should be pretty much interchangeable as far as I know.

 

That's pretty much what I was thinking but didn't know 100% seeing how they changed things in the engine compartment in 87 to fit the 4.0. I was hoping the 86 would hold out till the 88 was back on the road. :headpop:

[Pete M]

I'd try to keep the 5-spd. :thumbsup:

[JeepcoMJ]

Well checking the oil today in the 86 was depressing. I found the white foam under the cap. :fs1: Oil has a faint smell of gas so I'm thinking it has a bad head gasket or a crack some place. Anyhow, I have the 2.5 that came out of the 88. I'm thinking, if the 86's 2.5 goes, swapping in the 88's. Plan will be pulling the 2.5 with 5spd out and putting the 2.5 with 4spd in. Is this a direct swap or are there differences between the two ie wiring, sensors, or what not?

 

:cheers:

 

 

the only differences I can guarantee are that the throttle body has two more vacuum holes in the 86...so you may need to swap those. I also believe the intake is different.

 

I had an 86 cherokee that I put an 88 motor (88 intake and TB) and really only had to tee two vacuum lines (can't remember to what)in so literally the same swap

 

the other [slight] difference may be the oil pressure and temperature sending units. you may have to swap those...i cannot guarantee this (unless the 88 had dummy and the 86 has gauges...then it's a guaranteed necessity).

 

you will need to buy oil filters for an 88 motor after the install...they changed the oil filter adapter in 87.

 

the transmissions are the same. buy a clutch while you're at it, seperate the transmissions (outside the truck), and install a new clutch.

 

 

all other sensors are the same, as is the injector on the throttle body.

 

motor mounts are the same.

 

thermostat housing SHOULD be the same

water pump SHOULD be the same.

 

everything else serpentine wise is either the same or interchangeable. I would just stick with everything off the 88 motor and complete the switch to serpentine (unless it's already a late 86 production with serpentine)

 

-Pat

[mfpdm]

I'd try to keep the 5-spd. :thumbsup:

 

Well that brings up another problem. It lost 5th quite some time ago so it's a 4spd anyhow. At least until I get brave enough to pull it apart. I'm thinking that it may be just like the T-5's 5th problem where the clip breaks and allows the gear to slip. It won't even shift into 5th when parked, which I believe would eliminate the syncro. :dunno:

 

 

everything else serpentine wise is either the same or interchangeable. I would just stick with everything off the 88 motor and complete the switch to serpentine (unless it's already a late 86 production with serpentine)

 

-Pat

 

Yep it has the serpentine belt so I hope I can put all of the 86 accessories on the 88. Especially the AC, even though it doesn't work at the moment. :D

 

I'll probably need to swap the TB and injector from the 86 to the 88 as I kind of jacked up the 88's trying to get it off. :doh:

 

Thanks for the inputs. I'm not totally sure I'll do the swap as the 88 had a low end tap. Was going to rebuild it one day. Sad thing is, the 86's still sounds and runs good. I may bite the bullet and pull the head but I at least wanted to make sure I have a backup plan.

 

Backup plan to the backup plan is to offer it up for sale as is with a spare motor and other parts.

 

:cheers: