To Swap? or not to swap?

[ahuggins6]

I was given a 99 4dr SOHC by a neighbor lady whose husband had some down with demensia. Soon after driving it a few years, I pulled the motor and put a timing set in it (my second vehicle to do this to, having sworn the first time that I wouldn't do it again.) I got this one all back together and soon after getting it back on the road, smelled oil burning. I've always suspected it to be leaking at the back of the jack shaft since I made no attempt to seal that plug beside knocking it in square to the hole and flush to the block. However, it seems like it may be leaking everywhere--valve covers, oil pan and so on. IDK. I've been mechanicing since I was about 10yo--a LONG time ago. You'd think that when I put new gaskets all over an engine, they wouldn't leak???? Also, the chain rattle never really went away. Yes, i used a cheaper set, so I'm thinking I should put a new pair of tensioners in it??

Anyway, fast forward to today. Was driving down the road when I heard a rattle I couldn't relate to the chains. I decided to pull over and look, but before I came to a stop, the engine just died. Turned out the top radiator hose had blown off the radiator, and even further, the plastic end on the radiator had blown open. Temp gauge still reads normal hours later with the key off! I had my dad bring my truck and trailer to get me, and it fired up and drove on the trailer. So I know it still runs, right?

To get to the issue: I have two other V8 explorers here waiting to power early bronco projects. I don't think it would be hard to V8 swap it, but I'm not sure just how many parts have to be changed outside the engine and mounts, trans, harness, drive shaft(??), and radiator. Does the exhaust manifolds come to the same points on both engines?

Or should I just pull the V6, fix the leaks and get a new radiator for that--assuming the engine didn't freeze in the -4 degree temps last week. A year and a half ago, I had overheating issues and found the radiator stopped up, so it got another radiator out of the junkyard which I have not until today had a problem with.

What do you guys think? I'm not driving it a lot these days due to COVID and working from home, but my other vehicles are a super duty with 6.0 that needs injectors rebuilt and possibly new heads any day and my early bronco which I have basically rebuilt from the ground up and is technically more dependable than the other two. When I am driving it, it's typically my ride to work three hours from home on Tuesday and back home on Thursday, so lots of miles and far from home. Fuel mileage will be somewhat of a concern.

 

[German Engineer]

... IDK. I've been mechanicing since I was about 10yo--a LONG time ago. You'd think that when I put new gaskets all over an engine, they wouldn't leak???? Also, the chain rattle never really went away. Yes, i used a cheaper set, so I'm thinking I should put a new pair of tensioners in it??...

Don't get me wrong, of course you "would think" that, but that alone is no guarantee you really did everything right (which you may very well have). But as of now from what you describe, sadly it looks like that's exactly what happened: The engine now leaks all over. - So just don't overthink it and move on.

There are a lot of things one could possibly do wrong.
- Did you carefully torque the anti-fatigue-bolts down by the book, just right according to the exact specifications and the vehicle specific procedure?
- Did you reuse the old anti-fatigue bolts instead of installing new ones?
(Not everyone is aware that anti-fatigue bolts are carefully designed and to be installed with specific torque specifications, otherwise they will either not last very long at all, or they will simply not hold the engine together enough to prevent leaks. They are generally also not meant to be reinstalled after disassembly, but "should" be replaced with new ones. - At least when doing the repairs "by the book".)
- Were the surfaces properly cleaned/ prepared before installing the gaskets?

- Or did the engine simply overheat so much that the gaskets burned up and that's what's now caused all the leaks? (This might possibly and could very well be the main or even the only cause for what happened. Depending on what exactly happened and how hot the engine got, it very well may - or may not be the explanation.)

...Who knows.

- So ask yourself, do you believe you did all the repairs right the first time, or not? - And are you confident you will be able to get it working right this time?

And try your best to figure out what the (main) problem was, so that you know what to "fix" in order to prevent it from happening again this time.

Other than those basic questions I would say that maybe the best way to decide which way to go, is by starting to further diagnose the current status of the V6 engine that's already in the vehicle.
Maybe do a compression test first if you haven't, or just go ahead and take off the cylinder heads and have a good look at everything.
Some reasonable tests that could be very helpful you will of course not have the professional equipment to conduct. A pressurized check for cracks for example could be very useful, so you may be left guessing hoping here and there.

I don't know what diagnostics you've done so far, but at first I would normally try to check out if the engine is worth fixing at all and whether you might possibly even be able to repair it without having to pull it out.

Good luck!

 

[ahuggins6]

Don't get me wrong,

Good stuff there. I certainly appreciate the input. It fired up and drove on and off the trailer and sounded like it always has, so I don't think the engine is hurt. I just have the question of how low the antifreeze could protect it in that deep freeze. Did it pop a headgasket (or crack the block/heads), which then popped the radiator.

I'm gonna sleep on it a few nights and see what I come up with. I welcome input from others too!

 

[C420sailor]

V8 swap is a big job. If you have a donor vehicle, you’re set...but it’s still a ****load of work.

 

[CDW6212R]

Given the trouble of the SOHC, the current one with lots of oil outside, a 302/4R donor, I'd do the swap if it isn't a must have vehicle for a couple of weeks. You can find all the help you need here in multiple threads about the swap.

You will have to decide about the fuel system type, 99+ is returnless, and keeping that would be the simplest way. So a 99-01 302 Explorer will have the matching fuel system parts, those PCM's will work, and the cat pipes should work with your V6 muffler etc.

You can use either radiator, but the V6 has a much better AC condenser bracket, so use that and a V6 radiator.

 

[ahuggins6]

PATS: I read that the PATS module and the PCM are programmed together. So I'd have to swap that module too? I"m not sure I have a programmed key for the donor. If so, the battery is probably long since dead.

I certainly wouldn't mind freshening up a 5.0 vs redoing the timing crap on the 4.0 with a rattle--that might have a cracked head or block anyway... The same lady that gave me these two explorers had previously given me a 5.0 that was in the back of a pickup I helped her sell. The hatching in the cyl looked brand new, so I put new bearings in that one and stuck it in my early bronco. Once I got the fuel pump right, I haven't had a single problem with that engine.

Again, the reason for even keeping an explorer around is because at some point, i'll be making long trips for work every week and fuel mileage will be something of a concern.

 

[CDW6212R]

PATS: I read that the PATS module and the PCM are programmed together. So I'd have to swap that module too? I"m not sure I have a programmed key for the donor. If so, the battery is probably long since dead.

I certainly wouldn't mind freshening up a 5.0 vs redoing the timing crap on the 4.0 with a rattle--that might have a cracked head or block anyway... The same lady that gave me these two explorers had previously given me a 5.0 that was in the back of a pickup I helped her sell. The hatching in the cyl looked brand new, so I put new bearings in that one and stuck it in my early bronco. Once I got the fuel pump right, I haven't had a single problem with that engine.

Again, the reason for even keeping an explorer around is because at some point, i'll be making long trips for work every week and fuel mileage will be something of a concern.

You have the matching PCM/PATS modules in the donor vehicle, you need both, and two keys from that vehicle ideally. You can program any keys to work, but it takes a special service tool, which is in more hands now(some key shops have them).

The fuel mileage is not a ton different from the 4.0 to the 5.0, the tire size and gearing has as much affect on that. A 302 will be in a 3.73 truck, it will be notably worse if you put it in a 4.10 geared truck, say 18mpg at best on the highway. The 4.0 will hit about 20mpg with 3.73:1 gears, maybe not with 4.10's. So the difference is in the 2mpg range at most, most owners would tell you. That's about 10%, so do figure that in to your needs.

If all you need is fuel mileage for long trips, then the 4500lbs Explorer isn't a good solution. Most later model sedans will do over 30mpg easily.

 

[ahuggins6]

This thing has only gotten as much as 19mpg with a strong tail wind. I can't stand driving sedans. I need to be able to see thru/around the vehicle in front of me. I don't focus on the car in front of me in traffic. I'm looking three or four cars up.

I just don't want to find myself unable to get 16-17. I was thinking my ex has 3.55 gears. if not, perhaps it will get them! LOL.

Thanks for the info. I'm gonna get a radiator ordered so I can at least be looking into what might have caused the problem and then go from there.

 

[Mbrooks420]

16-17 is attainable if you keep a stock size/weight tire, especially with a 3.55 gear.

 

[CDW6212R]

Ditto, the 16-17mpg level is normal for the 5.0 due to typical old age and various old worn parts(external). The 4.0 has that little extra potential for mpg, but few people see much more than the 5.0 gets. For lots of highway driving, the 3.55 gear might be best, but the 3.73 is not bad at all. My old 93 4WD with 3.73's, stock 29" tires, got 20mpg going over 1100 miles to SD. That's very good, and it was the OHV V6 in stock condition, in about 2003(they announced the Firestone recall while we were there). Those Firestone tires did very well for us, and they were set to 34 and 32psi cold.

Work on your truck to get the cooling system back up, and see how it is then. The 4.0's are tough engines(besides the SOHC timing chain system), they don't blow a head gasket easily. Replace the thermostat and all hoses that aren't known to be relatively new. Buy a quality radiator, note there are now all aluminum versions, about $150 on eBay or Amazon. Use as much anti-freeze as your climate needs(no more), and an additive like Water Weter. With high quality engine oil, and air filter, the SOHC can live a long time.

 

[C420sailor]

If fuel mileage is the goal, slow down. I regularly see 20-21 in my SOHC with a full size lightbar on the roof, but I do 60 give or take. My V8 is roughly the same.

If you’re doing 70-75 in these things, economy plummets. They’re about as aerodynamic as a brick.

 

[ahuggins6]

Following up. I bought an all aluminum radiator off ebay. Got it next day! Swapped it in, had to find fittings for the transmission lines--turned out it was just inverted flare fittings-- and then ran it long enough to see that it's not mixing water/oil or pushing air out the radiator. Then I began the process of flushing it. I even pulled the thermostat out to flush it.

Side notes mentioned in another thread... I pulled the rear tensioner out and spun the motor over enough to push the gunk from the oil passages. There was no gasket on the tensioner! Perhaps my leak is fixed now after spending an hour at the second closest dealer guiding the "parts man" thru his system to find this $6.90 piece. Both their parts counter people repeatedly asked if I had the vin. To me it didn't matter. They have computers with parts diagrams. I finally rolled my eyes and told them this motor was in my 1968 Bronco but it came from a 1999 Explorer. They looked at each other. One says, "I can't look that up." My dad says now they want to use dealers' parts people to search for stolen cars thru vin numbers. The older of the two finally got to the diagram with the timing set and then took his sweet time finding it on the shelf.

Ya'll, the Ford dealer in Texarkana is a waste of everyone's time. If you need service near Texarkana, you are way more than likely better off to drive to New Boston, TX to Johnston Ford. They treat their customers right--no, I don't work there.

Back to my Explorer. This thing runs much smoother now, but still has the clunking sound it had since I put the timing set in it three or four years ago. It's coming from the left valve cover and I really have no idea what it could be other than some bent/sticking valves. But if that was the case, it would be missing at least SOME compression on a cylinder or two and it would have a miss. ????

Maybe someone else has had the clunking noise I'm talking about.

 

[Mbrooks420]

Having cylinders a little low on compression wouldn’t necessarily cause a miss.

Have you done leak down tests?

 

[ahuggins6]

No. Not worried about it. Runs fine, just has some extra character. Less character than before, so I'm happy with it.

 

[Mbrooks420]

You brought it up.

 

[CDW6212R]

Try changing the oil one time with a step thicker oil, say 10-40 instead of 5-30 etc. If it changes the character of the noise at all, it might point to a lifter(follower), or the tensioners having less movement in them. Just a thought, no big deal is good news.