01 3.1J into 99 Mailibu 3.1M HHHEEELLLPPP Please

[jpfenny]

I was curious as to what all would need to be changed out to make this work... I have a 99 malibu that the oil pump quit and wiped out mains and a rod... Have this 3.1 out of a 01 Lumina thats been sitting in my garage with 6,200 miles on it... Didn't know what all would need swapped out and if considering the new engine has 30 additional horse if I would need a new PCM or different sensors or if I can direct bolt and call it a day... Trying to have this car running by 8am tomorrow for a job interview 1500 miles away on friday...

[Jonpro03]

Wait what? Why does it have 30 more horsepower?

The only thing you will want to change that I can think of is the fuel rail. The 99 has a 43.5psi FPR and the 01 has a 55psi FPR.
The motor mounts might be different, I don't know. But other than that, it should drop right in.

[bszopi]

Should just be a direct swap. Good luck on doing it by 8am! Not saying it can't be done, but...

[jpfenny]

In 2000 GM switched specifically to the 3.1 J motor and eliminated the M engine... At which point they also upgraded the engine with 30 additional horsepower over the 99 malibu 3.1, I am not sure about any other specifics as far as other 3.1's made in the 90's but the 99 malibu has 30 less horsepower compared to any 3.1 from 2000 forward.

[jpfenny]

In addition I also know replacement part wise, the Cam position sensor and Crank Position Sensor as far as replacement parts go, Are 2 different numbers between the 99 and 01. Which is why i was curious if it made a difference.

[jpfenny]

LOL I hear ya, Fortunately I already have the old engine out and new one mounted to the subframe... SO..... I just didn't know if I needed to swap out intakes and fuel injectors... or if anything else would be needed.

[Jonpro03]

Oh, now I understand. You're going from an LG8 to a L82. Large port to small port. Got it.

Aside from the fuel rail, you'll want to swap the upper and lower intake manifold, fuel injectors and the wire harness, at least the rear exhaust manifold and crossover pipe, and egr system. The sensors will all work.

I've done the same swap except backwards. I've swapped an L82 with a LG8. But I bought an EGR delete so I wouldn't have to mess with the exhaust manifolds.

[bszopi]

Worst comes to worst, all you need to do is swap sensors between engines.

As far as the HP, you are getting bad info from somewhere. The L82 (VIN M) engine is rated at 160-165hp (depending on application), whereas the LG8 (VIN J) engine is rated 170-175hp, again depending on which application.

[Jonpro03]

Oh and for simplicity sake, swap the alternator and bracket and the A/C condensor because I'm pretty sure they're different.

[bszopi]

Oh, now I understand. You're going from an LG8 to a L82. Large port to small port. Got it.

Aside from the fuel rail, you'll want to swap the upper and lower intake manifold, fuel injectors and the wire harness, at least the rear exhaust manifold and crossover pipe, and egr system. The sensors will all work.

I've done the same swap except backwards. I've swapped an L82 with a LG8. But I bought an EGR delete so I wouldn't have to mess with the exhaust manifolds.

Why would you want, let alone need, to switch intake manifolds?! 1999 and 2001 should all share the same EGR setup, as well as exhaust manifolds, etc. Swapping small port intakes onto a engine with existing large port intakes would be dumb.

[Jonpro03]

Good point brad, except backwards. He's swapping in a small port. So switching the intakes would be beneficial.

If the EGR system is the same, there's no need to swap exhaust manifolds as long as the downpipe is in the same location.

EDIT: nope, I went back and re-read it. you're right. he's swapping in a large port.

[bszopi]

Good point brad, except backwards. He's swapping in a small port. So switching the intakes would be beneficial.

If the EGR system is the same, there's no need to swap exhaust manifolds as long as the downpipe is in the same location.

Reread the initial thread. His 99 Malibu has spun rods. He has a 2001 engine. He's putting the 2001 engine into the 99 Malibu.

[jpfenny]

I am swapping from the L82 to the LG8 not backwards... car is a 99... new engine is from 01.... Which is where im confused... didn't know what to change, I've heard that the intake needed swapped due to egr issues and heard fuel injector rail needs swapped due to different pressures... Just wasn't sure if some or all or anything needed swapped from old engine to new engine to make this work properly, or if i didn't swap things out would I need a different PCM, and will the harness thats on the 01 engine match up to the pcm and power distribution box (fuse box) on the 99.

[bszopi]

Only thing I can think of is the harness for the fuel injectors not plugging in, in which case you could run the old fuel rail and injectors. If you are concerned with the EGR, just look at the 2 of them. If they look the same, then no reason to swap. They may be oriented differently, but I am almost positive they are the same. Only reason to change the rear exhaust manifold would be if the new exits differently than the old, and will no longer bolt up to the downpipe. If they exit the same, don't swap. If they don't, just swap the rear, as the front and crossover will be the same. Front cover possibly, but that usually just depends on mounting locations (ie, the new might not have the same holes as the old, therefore not allowing your mount to bolt up). Honestly, just take a few minutes to look over the 2 engines and look for differences. If there appear to be, swap over the old parts. The gain in HP is due to the improved heads and intake manifold, so all other parts really aren't going to matter.

[Jonpro03]

I am swapping from the L82 to the LG8 not backwards... car is a 99... new engine is from 01.... Which is where im confused... didn't know what to change, I've heard that the intake needed swapped due to egr issues and heard fuel injector rail needs swapped due to different pressures... Just wasn't sure if some or all or anything needed swapped from old engine to new engine to make this work properly, or if i didn't swap things out would I need a different PCM, and will the harness thats on the 01 engine match up to the pcm and power distribution box (fuse box) on the 99.

Sorry, I didn't mean to confuse you. I've done this swap that you're doing. If you've already got the motor in the car, have a look and see if the downpipe is in the right location. You don't need to swap the intake manifolds. You might need to swap the engine wiring harness if it doesn't plug into the car. I switched mine. I also used the L82 injectors and fuel rail so that I wouldn't have to tune the computer for the higher fuel pressure.