Considering engine swap from 4.0 SOHC...

[MillerAPF97XLT]

After reading the horror stories about the 4-liter SOHC engine on this forum, I have begun to think about searching for and rebuilding a replacement engine while I baby the one that's currently in the truck. I was hoping to get input on the most favorable replacement, ie, how difficult and/or worthwhile would it be to go with a 4.0 OHV or a 5.0 instead of poking the same problem engine back in. I think I've read on here that the SOHC only came with the 5-speed automatic behind it; will other engines bolt up to it, or would I be looking at a combo swap? And what do I give up versus what do I gain with a different engine? So far, the only trouble the engine is giving me is with the cooling system, but the fix is in the works for that. Just trying to plan ahead for the inevitable. Thanks in advance - Chris:exp:

 

[vroomzoomboom]

there were some SOHC's that had a manual, but i believe they were only 2wd, i could be wrong. they are rare. a ohv will bolt up to the trans, but you would need to change the engine harness, computer, and exhaust. if you are doing a 5L swap, you would need to change a lot of things. pretty much all the driveline would have to be swapped over. i did to a write up on how to do one. you would want to have a complete donor truck for it.

 

[MillerAPF97XLT]

Thanks, 'boom. I'd like to keep the existing automatic transmission and transfer case, so it's starting to look like a 4.0 OHV is going to get the nod. Fewer components to change to make it happen, right? The only thing that scares me about the SOHC is on the back of the passenger side head. If it weren't for all the nonsense involved in replacing the cam drive stuff back there (eventually), I'd be all about keeping it. Others, what are your thoughts? - Chris:exp:

 

[Mustang Guy]

The 4.0 SOHC is a good engine that when taken care of can last 150,000 + miles. For less money and less hassle than replacing it with something else, why not get yours rebuilt with QUALITY parts and enjoy it for a long time.

 

[Medic454]

The 4.0 SOHC is a good engine that when taken care of can last 150,000 + miles. For less money and less hassle than replacing it with something else, why not get yours rebuilt with QUALITY parts and enjoy it for a long time.

I have 180k on my stock V6 4.0 SOHC engine. No problems... If I do develop problems I plan on having it rebuilt or doing a Warrantied Re-manufactured, installed by an independent shop.

 

[slaughterrt]

I have 220k on my 1999 SOHC and it's giving me problems with the timing chains.

 

[Flash]

After reading the horror stories about the 4-liter SOHC engine on this forum, I have begun to think about searching for and rebuilding a replacement engine while I baby the one that's currently in the truck. :exp:

Is there actually anything wrong with the engine now?
If you replace the timing chain tensioners at the very first sign of start up rattle or preferably BEFORE, that engine will last just as long as anything else.
Granted, the timing chain guides are a weak point and the best longevity is achieved by changing them for the improved steel backed guides.

If you are going to change out the engine, well, lifting the engine out is the hardest part of replacing the chain guides with the better ones, then your engine will slip right back in where it belongs with no fuss.

If your engine has been rattling for a while or worse, you found plastic in the sump, then it's time to seriously think about lifting it to replace or repair.

 

[MillerAPF97XLT]

Thanks to all so far. No, as yet the engine is not giving any real mechanical troubles. The thermostat housing is leaking, but I'm in the process of getting the parts to do the upgrade/repair for that. I am just weighing the relative value of repairing this engine, when the need arises, versus replacing it with a more service-friendly engine. If all the cam drive components were on the front of the engine, this thread wouldn't exist; servicing timing chains isn't rocket surgery to me anymore, I just don't like pulling engines. Especially at home, after doing it at work. If I have to do it to something I own, a better option is going in if one is available. I would much rather drive my vehicles than HAVE to be working on them. Looking more like the SOHC might get to stay, though. Keep the thoughts coming, everyone. TIA - Chris

 

[rb142]

Fixing the timing chains -- when and IF that becomes necessary -- is a lot less work than trying to do an OHV conversion (not to mention the loss of power, etc.). Once you replace the chains, you won't ever need to do it again in the lifetime of the vehicle, so ongoing maintenance isn't an issue. As for not liking to pull engines, you have to do that anyway for a conversion. Just don't wait until the chains let go to fix them and get back to enjoying your vehicle.

 

[MillerAPF97XLT]

Thanks, rb142. As it happens, I don't think I'm under any pressure to do anything but maintenance for a while; while I was out with the truck earlier today, I saw that it only has 163,x.. miles on the clock. Sounds like, from what I'm reading here, I've got 2-4 years before it should start making racket. And maybe longer if I replace the tensioners BEFORE the noise starts. Pretty sure I wouldn't want to lose power just to have all my cam drive stuff on the front of the engine, though. Leaning a little more towards keeping the SOHC. Keep it coming, "Ex-ers". Chris:exp:

 

[Boosted1993eg]

I would love a 5.0 swap in mine. I just bought a 4.0 99 explorer. 186k sounds beautiful. Everything but the heated seats works. Slightly bigger tires. I love it. I used to be a ford tech. Just replaced some dash bulbs and adjusted the shifter location

 

[MR.NORTEÑO]

rookie mistake

After reading the horror stories about the 4-liter SOHC engine on this forum, I have begun to think about searching for and rebuilding a replacement engine while I baby the one that's currently in the truck. I was hoping to get input on the most favorable replacement, ie, how difficult and/or worthwhile would it be to go with a 4.0 OHV or a 5.0 instead of poking the same problem engine back in. I think I've read on here that the SOHC only came with the 5-speed automatic behind it; will other engines bolt up to it, or would I be looking at a combo swap? And what do I give up versus what do I gain with a different engine? So far, the only trouble the engine is giving me is with the cooling system, but the fix is in the works for that. Just trying to plan ahead for the inevitable. Thanks in advance - Chris:exp:

 

[kevinspann]

As said, with all of the changes you have to make to swap to a different engine, it's easier to fix or replace what you have. If you had an entire donor vehicle, that's one thing, but considering most second gen Explorers are selling well under $3000, it's far simpler to just sell yours and buy what you want.

Pulling the SOHC isn't that bad, it's a 60 degree engine so it's rather narrow. The 5.0 is more difficult.

The 4.0 OHV should bolt up to the SOHC trans, but I'm not sure about controlling it with the same year OHV PCM. I think the earlier OHV had the 4R55E transmission.

 

[Tech By Trade]

Wont work. you pretty much need to swap all the guts out of a donor vehicle. Best bet is to build up a SOHC and have it in waiting for when yours grenades.