i have a 1999 neon sport with a dohc motor ... i want to know if it is possible to put a sohc motor in it ??? if it is possible how hard is the swap ??? thanks for any info and help ... i found a good deal on a sohc motor with only 70k miles and my dohc motor has 174k and i'm starting to have some trouble with it
rice_eater
04-20-2006, 06:10 PM
SOHC engine will fit just fine, a direct swap. It will even mate up to your existing transmission. You will, however, need a SOHC PCM from the correct year in order to run the engine. They are cheap, however, so dont worry ($30-$50 on ebay). I'm not sure if you'll need a '99 PCM (97-99 will work) or the year PCM of the SOHC engine. Maybe someone can help us out on this one....? I do know that the PCM's were different for '95, '96, and then '97-'99, and were also different between SOHC and DOHC engines. Good Luck.
dodgeneonACR98
04-21-2006, 03:12 AM
Why not get the SOHC motor tear it down and put on your DOHC head and not worry about getting a PCM. After driving the Dohc with a 5 spd yould hate a SOHC unless of coarse the car in an ATX then yould be better off with the SOHC. The blocks are the same but the heads are different thats what makes it DOHC or SOHC. It might mean a little more down time but hell it will be worth the time! And might save you a few bucks not needing a SOHC PCM. If you do EVER have the heads off a car for anyreason be sure to buy new head bolts with your gasket set. OR the head may leak due to streatched out bolts. Thats my oppinion. Good luck!
stewartd44
04-21-2006, 08:49 AM
I thank both of you for the information it really helps. I need to have as little down time as possible the car is my only form of transportation right now. What I plan on doing is buying the whole car from the junk yard. It was hit on the drivers side behind the front door so the engine, trans, and pcm are fine. My plan is to run the sohc and take my time redoing my dohc. I hope to have another car before long so my neon can be my little toy project. Thanks again and have a good weekend
rice_eater
04-21-2006, 05:21 PM
Good luck, let us know how everything goes.
RadarLove
04-23-2006, 02:25 PM
Your DOHC PCM will run the SOHC just fine (keep using premium), although you can swap in the PCM from the SOHC if it is a '97-'99 (and same tranny) if you want to run regular unleaded for a while. DOHC PCM on a SOHC will run a little richer at idle and WOT, that's it.
You may need to swap a few sensors/pigtails depending on what year the SOHC donor is. And the coolant temp sensor is in a different location, so you'll have to reroute that wire. You'll have to use the SOHC intake and exhaust manifolds (and TB, or just swap the TPS). Other than than, a pretty straightforward swap.
Best of luck!
95moparracer
04-23-2006, 02:31 PM
the reverse light sensor or w/e on the tranny between atx and mtx is different but the sohc and dohc tranny mtx is same sept the gears. also the pcms will work as long as the donor is not 95 cause 95 is a single plug not a dual plug. the dohc one will run the car but u'll go through extra gas, car may seem quicker then a normal sohc but ur dumping more fuel! other then that and well u'll be able to go to 135 instead of 120 lol im not sure if there is ne other difference!
rice_eater
04-23-2006, 04:05 PM
the 135mph limiter is only on the ACR and R/T PCMs... not all DOHC PCMs.
and transmission sensors are irrelevant, hes swapping engines, not trannies.
stewartd44
04-24-2006, 09:46 AM
Well I bought the wrecked car this weekend so i should have every thing i need. I'm going to plan the engine swap in a couple weeks or so. I want to go ahead and replace the timing belt and water pump while i have the motor out of the car too. Thanks to all of you for the information I will let you know how it goes
RadarLove
04-29-2006, 11:30 PM
also the pcms will work as long as the donor is not 95 cause 95 is a single plug not a dual plug. the dohc one will run the car but u'll go through extra gas, car may seem quicker then a normal sohc but ur dumping more fuel! other then that and well u'll be able to go to 135 instead of 120 lol im not sure if there is ne other difference!
The '96 pinout is different. Yes, it fits, but your rad fans won't work if you use a '96 PCM on a '97-up harness or vice versa.
stewartd44
05-01-2006, 08:56 AM
so as long as I am 97-up I am ok ?
RadarLove
05-02-2006, 05:16 AM
The donor motor doesn't make a difference, although keep an eye on the sensor connectors, and cut and splice pigtails as needed, or just swap out sensors. If you are keeping your stock wiring harness (which you should) and your stock PCM (which you can), then no worries. If you'd like to put in a SOHC PCM, then make sure it's a '97-'99, and the tranny matches (atx/mtx). If you happen to find a '96 SOHC PCM for a steal, then you have to swap out 1 pin in the connector to the PCM and it should work fine. I'd have to look up which pin though...
stewartd44
05-15-2006, 09:52 AM
well I made the engine swap this weekend ... the sohc runs great ... all of the plugs were the same ... I did have to change the ecu out .... I had the most trouble with the axles man that sucks ...lol...i have a vibration now when i accelerate once that is fixed it will be great...thanks again for all the help
