Skip the auto shop - Our mechanics make house calls

Q: Automatic transmission problems after engine swap

asked by on

My Mitsubishi Space Wagon 2001 engine was replaced with a 2000 Mitsubishi Gallant engine and now the automatic transmission keeps reviving up once it is in gear 3 before engaging, and revs up at exactly 50 km/hour, then same thing when slowing down too.
My car has an automatic transmission.

Hello there, thanks for writing in.

If the issue occurred after the engine was swapped, then it may be possible that the issue is related to the swap. The symptoms you describe can be caused by a variety of issues from the swap. If you suspect the problem is transmission-related, a few things I would check are the fluid level, shift solenoids, the pressure switch. Similar symptoms can also be caused by problems with the vehicle’s engine management system.

If you would like help diagnosing this issue, consider having an expert automotive technician from YourMechanic come to your home or office to inspect your vehicle for you, and make or suggest any repairs as needed.

Was this answer helpful?

Need advice from certified mechanic? Get help now!

Over 1000 mechanics are ready to answer your question.
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Ask a Mechanic
(100% Free)

Have a car question? Get free advice from our top-rated mechanics.

Ask A Mechanic
Over 10,000 questions answered!

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing

Get a quote

What others are asking

Q: What is wrong with my car and how can I fix it? I know the gear is slipping but I don't know how to resolve it

When your internal transmission clutches start to slip from excessive wear then the only way to fix the problem is to rebuild or replace the transmission. Each gear may slip differently and some gears may not slip at all. Servicing...

Q: Why does fuse 13 under the hood keep blowing out?

The job of a fuse is to prevent electrical shorts or over voltage situations from damaging wiring or electronic components in the vehicle. If a fuse keeps blowing, there is an electrical short in that circuit that is applying too...

Q: Trying to put a Duramax engine in

Hey there. This can be done for sure, but it isn't a direct bolt in process. This is a project for someone with experience and passion for working on cars, or the budget to pay someone as much as a...

Related articles

What Causes Hoses to Leak?
While the largest part of your engine is mechanical, hydraulics plays a significant role. You’ll find fluids at work in a number of different areas. Your car's fluids include: Engine oil Transmission...
P0240 OBD-II Trouble Code: Turbocharger Boost Sensor B Circuit Range/Performance
P0240 code definition Turbocharger Boost Sensor B Circuit Range/Performance What the P0240 code means P0240 is an OBD-II generic code triggered when the Engine Control Module (ECM) detects the intake boost...
P2428 OBD-II Trouble Code: Exhaust Gas Temperature Too High Bank 1
P2428 code definition A P2428 trouble code signifies that the PCM has detected a problem in the exhaust gas temperature sensor circuit in bank 1, which subsequently contains the number one...