Ranger SOHC engine swap notes | Ford Explorer Forums - Serious Explorations

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Ranger SOHC engine swap notes


New Member
October 19, 2008
Reaction score
City, State
Santa Barbara, CA
Year, Model & Trim Level
2001 XLT

My Explorer is a 2001 XLT with the 4.0L SOHC motor. I purchased it in 2003 with 25k on the odometer and it has been a great truck for my wife and I. Last Thanksgiving we went out to the car, pumpkin pie in hand, to head to a friend’s house. After I started the car we heard a loud crack and the engine started to run rough. I turned the car off, gave it a few seconds, and proceeded to restart the engine. It ran rough before another crack and what sounded like a thousand BBs rattling in the engine. After that it seized and wouldn’t turn over.

Looking at it the next day I saw a bit of antifreeze mixed with oil coming out of the y-pipe connection on the driver’s side. I figured something happened to the head gasket. I pulled the lower oil pan and saw some plastic pieces in the bottom. After some work on top of the engine I pulled the driver’s side valve cover and saw that the exhaust valve on the #6 cylinder was gone. The spring had broken, leaving parts to fly everywhere. The valve had sunk into the cylinder, hitting the piston and preventing the engine from turning over.

It looks like one of the timing chain guides let go which let the engine timing slip. One of the valves then hit the piston, which broke the hardware in the head. After that it was ‘catastrophic engine failure’.

What follows is an account of some of the things I learned when swapping a newer Ranger engine in. I have done a few engine swaps before, but nothing in the last fifteen years. So, in some sense I am a bit rusty. Also, all the work before was in a well-equipped garage. This was done in the carport of an apartment complex.

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Removing the old engine

To determine the cause of the engine trouble, and to get the crankshaft turning again, I ended up tearing down the old motor quite a bit before I lifted it out. I would do it differently next time - you can leave quite a bit of stuff on the engine if you do it right.

Some notes:

• Removing the battery box and wheel well liners freed up a lot of access. Highly recommended. It takes time to get the wheels off and get the liners out, but it was worth it later in so many ways.

• On the recommendation of some Forum members I used the Ziploc/Sharpie marker method of hardware tagging. This worked incredibly well. Between work sessions I would keep all my tools and hardware in the cargo area of the Explorer.

• The manifold to y-pipe bolts were an incredible pain. After years of enduring New Hampshire road salt the bolts had seriously rusted and thinned. All told I got one bolt out, sheared the heads of two others off, and Dremel’d the last one in half. Then I found out the pipe still had lots of coolant in it...

• I also broke one of the y-pipe to collector studs lower in the exhaust system. I ended up having to cut the two rear spring bolt connections joining the collector/cats to the muffler so I could remove the pipe and repair the broken stud. Suffice it to say I won’t need any iron supplements for a while.

• The connections on the EGR tube are 27mm. This is an impressive wrench to purchase at Sears, and somewhat suspicious to be seen with as you finish the rest of your 5k run. I read a lot of horror stories on the board about the EGR connections, but I soaked them with PB Blaster overnight and they weren’t terrible.

• The engine could still turn over about halfway in either direction before the #6 cylinder hit the remains of the exhaust valve. I was able to get three torque converter bolts off through the starter access hole before I noticed that the point where the cylinder hit was exactly where the fourth bolt would appear in the access hole. I could see the bolt, but it was impossible to get any kind of wrench or ratchet on it.

• I was going to take the driver’s side cylinder head off so that I could have the engine turn for the final torque converter unbolting. I was feeling pretty home-free when I ended up completely stripping the final head bolt. It was the one closest to the firewall on the bottom. Man, was I pissed at myself.

• To get the engine turned so I could take the final bolt off the torque converter I removed the upper oil pan (not fun) and unbolted the #6 piston from the crankshaft. At the bottom of its stroke I pushed it up and away from the crankshaft and then to the side. I couldn’t take it out, but the extra room let the crank turn enough to get the final bolt off the TC.

• I ended up taking out the center console, cutting though the carpet, and removing the access panel so I could get to the upper bellhousing bolts. This proved to be the best way to get to the upper four bolts. I have seen others mention going at them with a long extension from under the car, but that sounds pretty difficult having looked at it from both angles.

Lifting the engine out

We used a polyester hoist sling to lift the old engine out. Since the upper and lower oil pans were off there was plenty of room to loop the sling through the bottom of the engine and around the heads. We also used several ratcheting straps to fine-tune the engine position for removal. I had read on the forum how the 1-ton hoists were a little short to reach the engine. One member even took their bumper off. I spent a little more and bought the 2-ton engine hoist with a 20% coupon from Harbor Freight. It had more reach, more height, and more capacity. It worked great without exception.

After making sure the transmission was supported the engine came off the bellhousing without a problem. A couple of pushes had it free of the torque converter. Our only trouble came when the driver’s side motor mount and mounting plate wouldn’t separate. They were rusted together something fierce. A lot of angry hammering and they were free. Road salt really had it in for me on this project.

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Putting in the new engine

I ended up getting an engine from a parts recycler, LKQ, in Bakersfield, CA. My understanding is that they have locations all across the US. Working with them I could have a better selection of engines to choose from. The new engine also came with a warranty, so if it totally choked I could potentially get another one.

Criteria for the new engine:
- Not have a ton of miles, ideally less than 75k
- Not have the timing chain guide issues (2003+)
- Newer the better
- Documented swap success on the forum

I was all set to go with the Mustang SOHC engine swap, which has been done by several forum members, but I got hung up on California laws regarding engine swaps. It is legal to swap in the engine from a newer vehicle, but it has to be from the same weight class. I called up the CARB info line and asked if the Mustang engine would be allowed - it wasn’t. Essentially, I had to find something from a light truck. There weren’t many Explorer engines listed with LKQ, but there was a nice 2007 Ranger SOHC engine listed with 57k on the odometer. I hadn’t seen anyone swap anything newer than a 2006 Ranger engine on the forum, but I bought it anyway.

The first order of business was stripping off all of the Ranger-specific gear on the engine. I pretty much took it down to the bare block and heads. The electrical harness and vacuum harness were way different between the two trucks. The intake was a totally different design as well. All this had to go to make it an Explorer engine. I did try to keep as much as possible off of the newer engine though since it had half the miles of the old one.

What I kept from the Ranger engine:
- Fuel injectors (purchased adapters to go from EV1 to EV6 injector connection)
- Coil pack
- Spark plug wires
- Exhaust manifolds
- Crank pulley
- Idler pulley
- Water pump & pulley
- Belt tensioner
- Oil pan
- Oil dipstick
- Oil filter adapter (went from FL1A to PH2)
- Crankshaft sensor
- Camshaft sensor
- Knock sensor
- Oil pressure sensor
- EGR dual pressure sensor
- Engine mounting plates

Things I definitely had to change:
- Alternator bracket (different alternator mount)
- Thermostat housing (only had one sensor vs two in Explorer)
- Crankcase breather box (Ranger did not have one)
- Valve covers (different PCV routing and such)
- Intake manifold (simply didn’t work with the Explorer harnesses)
- EGR valve and intake connection (was setup for taller Ranger intake)
- Fuel rail (Ranger’s was slightly different, forget how)
- Wiring harness (way different)
- Vacuum harness (way different)

For everything else I didn’t mention you can assume came from the Explorer. For instance, the flexplate came from the Explorer since the Ranger engine didn’t have one with it. Also, other items that connected the engine to the truck like heater hoses and grounding straps were all from the Explorer.

Engine prep notes:

• Liberal use of shop towels to block intake ports and whatnot. I wasn’t about to ruin the new engine with a loose bolt or tool.

• Bought all new fuel injector o-rings for where the injectors meet the rail and the head. The o-rings for where the fuel rail meets the incoming fuel line were the same part number and I replaced those as well.

• I purchased a new valve cover gasket, but it was the wrong one. The Autozone computer said it was what I needed since the gasket was for engines built after July 2000 and mine was built in October. It seems that Ford still had old parts left over that they were using, because mine was totally the old style. I decided to just clean the old gasket and use hi-temp silicone around it.

• The lower gasket for the thermostat housing appears to be a Ford-only part. My dealer wanted $18 for a new one, if they could find one. He really wanted me to buy the whole housing kit for $280. I got some special water pump silicone, cleaned the gasket, and reinstalled it with some sealant around it. We will see how smart/dumb this move was over time.

• I bought other tune-up parts, such as spark plugs and new air filter, but I didn’t install them until I knew that the engine was running and I wouldn’t be pulling it back out. I also replaced some items just because, like the lower radiator hose.

Installing the new engine

We couldn’t use the hoist sling again because the oil pans were on the new engine. It was just too short. Instead we used a length of chain between the rear of the passenger head and the front of the driver’s side head. The upper transmission bellhousing bolts were perfect for this purpose. We used the ratchet straps again to fine-tune position. I can’t emphasize enough how helpful the ratchet straps were as we tried to get the engine centered and mated to the transmission.

It took some wrangling to get the torque converter pilot shaft seated, torque converter bolts through the flexplate holes, and to get the bellhousing lined up. My wife manned the engine hoist and I was under the car. It took us about 30 minutes to drop the engine in and get the lower four bellhousing bolts on. After that I installed the plates that go to the engine mounts and removed the crane.



I haven't had a chance to drive it yet since we cut the insurance on the truck after the engine died. Hopefully this weekend I will be able to run it out on the highway. At the moment it runs great in the driveway and purrs like a kitten when the gas pedal is down. There might be some more tweaks to make, but it looks good so far.

I want to say thanks to all the people who took the time to post their own experiences with engine swaps. The information on this forum was incredibly valuable - I never would have tried this engine swap without the knowledge posted around here. Thanks again.

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Very nice write-up.

I also used an 07 ranger engine but I put it in an 04. The engine I got had 34k on it. I have about 500 mi on it so far with no issues

Just found this thread would have been very helpful earlier, I am putting a 2004 Ranger engine in my 1999 Explorer. I did a lot of mixing and matching of parts and a few mods to make it all work, engine is dropped in but haven't installed the tranny yet.

Great details.

I apologize for bringing this one back from the dead, but I have one question...

Did your Ranger manifolds have studs on them where they connected to the exhaust pipes? And they mated up fine? I'd like to use the newer Ranger manifolds (my engine is a 2011, going into a 98), but I fear them not mating up properly.

I apologize for bringing this one back from the dead, but I have one question...

Did your Ranger manifolds have studs on them where they connected to the exhaust pipes? And they mated up fine? I'd like to use the newer Ranger manifolds (my engine is a 2011, going into a 98), but I fear them not mating up properly.

I had to modify the flanges on my truck. The 99 flange holes on my factory pipes where too narrow. I could not find and easy way to install new flanges or an inexpensive source for them. I ended up welding and extension on each side of the flange and made them work. Also I removed the factory studs because two were broken and the replacements I bought that were supposed to be the correct threads did not fit. I really don't like dealing with broken studs so I used a 5\16 grade 5 bolt that passed through the original threaded hold and used a nut on the other side. Slightly more complex to install but if I ever need to remove I can easily cut the smaller bolts and replace.