: 98 sts what fits



clintg
07-18-08, 10:37 AM
i have a 98 sts vin 9 that needs a motor. will an eldo vin 9 fit i was told there are some mounting boss diffrances.how bout like 01 sts motors do they work.i have heard that the new model motors are better. i dont mind some small changes but just wanna be sure it will work before i spend money on a motor.

tateos
07-18-08, 01:43 PM
The Eldo and STS are the same - you will need to use a '96-'99 motor unless you want to tackle some pretty big differences.

Depending on what's wrong with your motor, it might make sense to repair it rather than replace it. If you do need to replace it, I recommend you either replace it with an engine that has been inserted, or insert it yourself before you install it. I replaced the original engine with a blown HG in my '97 with a used engine, and that engine's HGs failed in 2 years.

CadillacSTS42005
07-19-08, 01:20 AM
no
it is not the same
the mounts are different
i dont think it will work...

tateos
07-21-08, 01:04 PM
no
it is not the same
the mounts are different
i dont think it will work...

You are saying that a '98 STS engine is different than a '99 Eldo engine?

CadillacSTS42005
07-22-08, 12:39 AM
correct
i could swear due to the different frame it wouldnt work
AJ or Ranger could confirm
think its the whole dogbone mount set up not on the Seville among other things...

danbuc
07-22-08, 11:37 AM
The Eldo was still based off theolder chansis that was discontinued in the Seville in '97. They used dogbones up top, and different mounting at the bottom due to the different subframe. Not sure how different they are mount wise, but the engines themselves are the same.

97EldoCoupe
07-24-08, 04:08 PM
The STS / Eldo engine is the same. In '98 they changed the timing cover slightly sometime during the year to accept the new engine mount of the '98-'04 STS. This is very minor- instead of the lower left corner of the timing cover being a complete 90 degree corner, it takes a short-cut across to allow for a new threaded bolt hole for the new engine mount. You can use a 96-99 engine for any car produced through those years except the 98-99 STS. They require an engine manufactured between 98-99 with that new bolt hole. Unless you want to modify the engine mount slightly, then you can even use an engine from 96 and 97. Easy way to check the engine is to jack up thee car and look underneath by the right front wheel. Either that or check for a part number stamp just above the harmonic damper- If it has the part number, it's the new design. The Eldorado kept the original style mounts through 2002 while the deville changed in 2000. Stay away from anything 95 and older if possible. They have the knock sensor in a completely different location. EGR is different on the 93-95 engines. Too many mods required to make those older engines work, but it can be done. I am working on a new modified motor mount bracket to allow a 96-97 engine to work in a 98-99 STS that will let the engine just bolt into place.

tateos
07-30-08, 02:24 PM
The STS / Eldo engine is the same. In '98 they changed the timing cover slightly sometime during the year to accept the new engine mount of the '98-'04 STS. This is very minor- instead of the lower left corner of the timing cover being a complete 90 degree corner, it takes a short-cut across to allow for a new threaded bolt hole for the new engine mount. You can use a 96-99 engine for any car produced through those years except the 98-99 STS. They require an engine manufactured between 98-99 with that new bolt hole. Unless you want to modify the engine mount slightly, then you can even use an engine from 96 and 97. Easy way to check the engine is to jack up thee car and look underneath by the right front wheel. Either that or check for a part number stamp just above the harmonic damper- If it has the part number, it's the new design. The Eldorado kept the original style mounts through 2002 while the deville changed in 2000. Stay away from anything 95 and older if possible. They have the knock sensor in a completely different location. EGR is different on the 93-95 engines. Too many mods required to make those older engines work, but it can be done. I am working on a new modified motor mount bracket to allow a 96-97 engine to work in a 98-99 STS that will let the engine just bolt into place.

Good info!