Attempting an Engine Swap: 05 (base) to 98 (GT) - both 3.8L V6 OHV 12V

**Wayv Tyde** · 06-13-2016

Hey guys and girls!
I just registered a moment ago cause I need help. I'm in a bit of a situation right now. Searching these forums for a few hours has yielded little information that I know I need.

Background: I like to think I'm pretty mechanically inclined. With no prior knowledge of cars of any sort (not even a single oil change under my belt), I removed, rebuilt, and replaced the tranny from my 02 Ford Escort ZX2. Yes, it did take me almost two full months

but I did it with minimal help (mostly helped with heavy lifting). Any additional info you need, please ask -- I will be watching this thread like a hawk.

Now: I have inherited from my dad two Grand Prixs, one is a (Red) 98 GT and one is a (Silver) 05 base. I looked at the VINs on a free VIN checker website and it said both engines were "3.8L V6 OHV 12V." The problem with Red is there was a leak somewhere and coolant made it's way into the engine. Apparently engines don't like that...

The problem with Silver is oncoming traffic redesigned the slick look of the Prix. Engine and tranny are still fine, though.

Biggest question: Is this at all possible?

I really like cars, and am going to have a lot of free time this summer. Time is barely an issue. I'd rather not have to spend too much money on these cars though. Also, I have been reading and I've come across a lot of "top swaps," I don't want to do that, unless it is FAR better/faster/stronger. You get me?

I think that about wraps it up. Again, if I failed to supply sufficient info to help you help me, please ask! I'm really excited about this, and I want to prove to my dad that I can do this (even if it is heavily supported by you guys

).

Thanks in advance, everyone!!

**Billycar11** · 06-13-2016

its not going to be a drop in install and you cant just swap engine you need the transmission too they are different generations plus who knows how you will get all the gauges to work swapping a new engine in to an old car it might be easier to fix the leak or get the damage repaired if possible

**Scottydoggs** · 06-13-2016

so your want the 05 engine in the 98 car right?

all you really have to do is use the upper intake its tb and its sensors off off the 98 's engine, and compare all engine sensors plugs, swap sensors if need be, most should plug right in tho.

you cant use the 05 tranny. its electronics are not the same. and the cable shiftier is not the same either.

**Swiggles** · 06-13-2016

Honestly the 98 motor is probably fine, might be a little hydrolocked but that can be taken care of. The lim (lower intake manifold) gasket went on but the head gaskets should be fine. Lim job is pretty easy, there's a how to video in the how to section.

How bad is the 05? Can find parts cheap enough of its not that bad.

**Wayv Tyde** · 06-13-2016

Originally Posted by Billycar11

its not going to be a drop in install and you cant just swap engine you need the transmission too they are different generations plus who knows how you will get all the gauges to work swapping a new engine in to an old car it might be easier to fix the leak or get the damage repaired if possible

Are you saying that the two aren't compatible and that I would need some sort of aftermarket parts and such? I was hoping that is was an easy drop 'n' install.
Thanks!

Originally Posted by Scottydoggs

so your want the 05 engine in the 98 car right?

all you really have to do is use the upper intake its tb and its sensors off off the 98 's engine, and compare all engine sensors plugs, swap sensors if need be, most should plug right in tho.

you cant use the 05 tranny. its electronics are not the same. and the cable shiftier is not the same either.

Yes, the 05 Series III engine is going to replace 98 Series II engine (if it's possible).

So, is that considered a top swap, only using the upper intake and sensors? Still quite new to the car scene.

Both trannys are fine, so that doesn't matter then.
Thanks!

Originally Posted by Swiggles

Honestly the 98 motor is probably fine, might be a little hydrolocked but that can be taken care of. The lim (lower intake manifold) gasket went on but the head gaskets should be fine. Lim job is pretty easy, there's a how to video in the how to section.

How bad is the 05? Can find parts cheap enough of its not that bad.

So you're saying that I could just fix the 98 motor instead of replacing it? Along with replacing the LIM gasket?

The 05 was totaled; it has a bunch of frame damage.
Thanks!

**Scottydoggs** · 06-13-2016

all you need to do is swap the intake and drop it in there really.

no its not a top swap lol you need to run the plastic intake and tb from the 98 cause one has cables and the 05 is dbw.

top swap is when you have a na block, then install supercharged heads lim and blower and all needed extra pulleys and a map sensor swap.

**NebTurboST5** · 06-13-2016

You could also leave the 05 motor together and just get a gen5 to l67 throttlebody adapter plate and just swqp throttle bodies...

**Scottydoggs** · 06-13-2016

come to think of it, your best off buying a new upper intake, dorman sells them and then mod your lim so it cant leak coolant any ever again and kill this engine.

how to mod a lim how to http://www.grandprixforums.net/threa...w-to-Mod-a-LIM

the thread on the upper intake failing, this is what likely happened to the 98 engine. http://www.grandprixforums.net/threa...hlight=failure

your lim looks different as you can see fromt he two threads, but the two ports being sealed stops it from leaking ever again.

**Wayv Tyde** · 06-13-2016

Is there any way to check to make sure that I don't have a broken piston? Or to see if I really do have a coolant leak? I just want to make sure I'm not getting into something that I don't need to. Although, it will be a learning experience either way. Also, is there any chance I can do all the repairs and replacements without removing the engine? Repairs being the mod to the LIM and the replacement being the new UIM.

**Scottydoggs** · 06-13-2016

did the engine lock up, aka it wont crank at all. did any one keep trying to crank it more then a few times? if so its likely junk.

if not, pull the spark plugs and then try to crank it. any coolant in the pistons will blow out now. if coolant comes out it hydro locked.

**FordMan77** · 06-14-2016

Originally Posted by Wayv Tyde

Is there any way to check to make sure that I don't have a broken piston?

Yea, do a compression test on the motor. If a piston is MIA you won't get anything on that cylinder since there is nothing there to compress the air.

**Wayv Tyde** · 06-15-2016

So my dad just told me that the engine turns over fine, but it just sounds horrendous. He says that he thinks the main crank shaft is rusted or rusting due to the coolant leaking in. That being said, I don't think modding the LIM and replacing that UIM will fix the 98. I think a proper replacement is in order. Thoughts?

**WarStryker13** · 06-15-2016

Coolant is supposed to have inherent anti-corrosion properties, otherwise our iron engine blocks and heads would have rusted apart decades ago. It's going to sound horrendous if there's coolant mixed into the oil. It might still be salvageable, but you would have to pull the heads off in order to fix it properly. dropping the 05 motor in with a throttle body adapter plate might be your best bet. IIRC the fuel rails from the 98 will fit over the 05's UIM, and line up with the injector holes, but I'm not 100% sure on that. Most of the other sensors are either in the same place, or aren't going to be moved over from the 05. The adapter plate you can get from ZZP for $100, and the rest should be plug and play. the MAF that is part of the intake tube for the 05 is inside the TB on the 98, the MAP sensor I'm not entirely sure on. I would keep the AC compressor and alternator from the 05 engine when you swap it in, it's just easier that way.

**Swiggles** · 06-15-2016

I know of a local that cleaned out the cylinders without taking the heads off. If I remember right he took the one spark plug out at a time and cranked it over with the icm disconnected and it spit all the coolant out of the hole. And a few oil changes to flush out the rest.

MAP sensor is in the same spot. Evap is in a different place but it's plug and play with the port and plug. Lims are the same so you wouldn't even need to take that off anything from the 05. Everything would "drop right in" just needs the throttle body adapter. And 98 fuel rail and injectors stay.

If you remove the ac compressor then you'll need to discharge and then recharge the system at shop before and after doing it. Better to leave yours in the engine bay during the swap.

This would be an UIM swap. Bill boost did some similar in his 00 regal ls.

If the 05 is totaled then just do the swap and part out the rest of the 05.