A couple years ago, we bought a fairly nice 1995 Ford Aerostar 2WD 4.0L. It had some neat mods the previous owner did, including Lincoln Mark VII disk brakes on the rear.

We bought it with 208,000 miles, and shortly after we bought it it developed a bad misfire. So I went ahead and told the shop we were going to bother with diagnosing it, I wanted both cylinder heads pulled off. So we went and stripped the motor down, and removed both cylinder heads. Sure enough, both heads were cracked and the exhaust seats were toast. So I bought new cylinder heads that had hardened steel exhaust seats, all new exhaust valves. I ported the new heads, matched the intake. All seemed good.

Put it all back together, one cylinder is completely dead. So we swap out injectors, and of course it already had all new ignition components. Made no difference at all. So we compression test it. #4 cylinder registers less than 20 psi. Around this time period my '97 Aerostar 4.0L blew a head gasket, for the third time. I was not going to fix the '97 again, the body was in terrible shape, and it was developing other age related problems.

So I pulled the engines from both vans. First the '97 motor, which I then proceeded to tear apart and sort out all its components. I recently had new rockers and pushrods. Basically stripped it down so I could compare components and make sure it didn't have any major catastrophic issues.

I then got the engine from the '95 an began to tear it apart. I was expecting that there would be a catastrophic problem, like broken rings, on the #4 cylinder. Was extremely perplexed when I could not find any obvious reasons why the compression on that cylinder was low. The piston wasn't broken or melted, the rings were intact, there was only minor scuffing on the cylinder walls, not anything that would explain the low compression. There was however bits of aluminum embedded in the face of the #4 , #1, #2, and #3 pistons. But regardless, I made the decision to junk the '95 block and pistons.




I took the '95 crank, rods, heads and intake. I then took the '97 block, had it decked to insure it was flat. Holy crap, it had major distortions. Like often happens with old motors, the deck surface had deformed such that it was raised around each bolt. The factory knish was terrible too. It took 6 thousands to bring it back to a flat surface. We didn't take chances, the new heads were resurfaced as well. Since they were new and well made, it only took about half a thou to clean them up. Also positively identified the source of the '97 motor blowing head gaskets. Between the deformed deck surface, and the corrosion that had eaten through and severely pitted the aluminum timing cover, which has coolant passages through it.







Next ordered a full rebuild kit with new pistons. Replaced all bearings, gaskets, oil pump. Everything was assembled with Jo Gibbs break in oil as an assembly lube. I used the '97 block, with the '95 crank, '95 rods, new pistons for a '95 motor (same as '94 and older Ranger/Explorer). The '97 cam, '97 pushrods and rockers. The pushrods and rockers were assembled using Jo Gibbs assembly lube instead of motor oil, since pushrod and rocker wear is a common issue on these motors due to a lack of adequate lubrication. Might as well use a high ZDDP fully synthetic assembly lube on those problem areas.




Used the '95 heads. Once everything got back together and assembled as though it was a '95 motor with the better parts from the later motor. It also got new set of injectors. When I went to install the intake, I found a surprise. There were major dings in the fuel rail. The intake had no indications of issues,, probably because any damage was removed when I had ported and matched it to the heads. But the fuel rail had noticeable dings in the soft aluminum, that appeared as though something struck it from inside the motor, like shards of metal had blasted backwards up the intake with enough force to leave impressions in the rail. Something catastrophic happened to the old '95 motor, it had damage that looked like something metal had been sucked though it and bounced around inside. I decided to use the '97 fuel rail.









I installed rebuilt fuel injectors, which had been flow balanced and made a matching set. I then installed the '95 coil pack, which was known good. I installed a Magnacore wire set and Autolite fine wire iridium plugs. The whole motor was also painted in a beautiful 2 tone scheme, with old Ford Grey on the block, intake, and oil pan, and Old Ford blue on the valve covers, accessory brackets, and various other pieces. The exhaust manifolds got a coat of high temp ceramic coating. The motor was pretty much good to go. It also got the original hard plastic vacuum lines replaced with formed metal ones. Take that vacuum leaks. The stock ones get backed by heat, and even rubber ones break down from heat, but metal, that will never deteriorate from the hot engine compartment. It also got a variable oil pressure sensor (mods to the gauge required) so that actual oil pressure would be indicated.

I do not have pictures of the installation process, as I let someone else handle putting the motor back in. At the same time, I had the A4LD that came out of my old '94 van that got totaled a few years ago, get freshened up. It was built for heavy towing, so it was already overkill, this van will not be used nearly as hard. It had to be converted to a 2WD trans however, since the '94 was an AWD model.

There were some additional changes and upgrades to other portions of the van to accept other radical mods. I had a custom made 3" thick all aluminum radiator. Compare to the stock 1 1/4" thick one. Because the stock fan won't clear the thicker core, it has an electric van with a controller and a custom made fan shroud. Rather than filling the system with conventional water/glycol coolant, this motor is using Evans Waterless Coolant. No water means:

No corrosion. The problem with water based coolant is that water acts as a corrosive electrolyte.
No boiling. Water boils at 212F and builds up a lot of pressure. This pressure causes hoses to stress, and it tried to force its way out of any leak it can. Evens waterless Coolant doesn't boil till 380 degrees, so it only builds up about psi pressure, and does not come out as a geyser, even if you open the cap on a fully hot system. I have tested this, removing the cap causes a short hiss that sounds like opening a soda can.
It never needs to be changed or replaced. Since it doesn't corrode, no more plugged radiators, heater cores, or other problems. It doesn't ever need to be flushed or changed. If the system ever needs to be opened, you drain and capture the coolant, and then screen it before reusing it.
I've noticed more even and consistent cooling so far. Summer will be the real test obviously, but here in the early spring it seems to work really real well. Water based coolants cavitate, causing hot spots in the cylinder head, and uneven cooling. Since this stuff doesn't boil, it protects the engine better as temperatures get hotter. Water based coolants do not protect and engine very well once the temperatures get over 220F. This will protect the engine from overheating all the way to 280F.



All said and done, it looks great, runs great, had excellent power (a lot more than stock due to the '97 cam with a '95 motor, and the porting work). The trans shifts perfectly. Engine idles smoother than I've ever had a 4.0L run.

Gonna take it on its first long trip since it was rebuilt this coming weekend, gonna be almost 2,000 miles round trip.

 

Awesome work!

 

That is an awesome looking motor, love the colors.

So are you going to Dyno it to see if there are any HP/TQ increases with the porting?

Also, out of curiousity, why did you go with the cast intake instead of the plastic intake from the 97?

And did the 95 not have EGR?

 

No, the '95 did not have EGR. The plastic intake on the '97 offers no real benefits, in fact, because the plastic warps, Ford had to later offer a redesigned gasket set because the original ones could not adapt to the severe warpage. Basically based upon realistic experience, the plastic intake is junk. I had to replace the intake gaskets on the '97 3 times due to intake leaks. The first time I used a Fel-Pro Perma-Dry gasket set and it leaked. Then I used the updated Motorcraft set which fixed it. Then one of the EGR o-rings got sucked inside creating a massive vacuum leak. Its a messed-up problem-prone design. I'm sure if they had made later years they would have fixed the flaws eventually.

Yes, the '97 had EGR, but the '95 does not, would be way too complicated to preserve the EGR. The '97 motor used a different computer, EGR isn't just the mechanical/parts, it requires matching electronics. The '95 just didn't have it.

I am not going to waste money with doing a professional dyno test. Porting makes a difference, in fact, flow is why these motors produce such low power ratings and why modern engines are much better. If I cared about quarter mile times, I'd consider a dyne test, but for this setup, actual performance is not important. Using a rough accelerometer based dyno, which is obviously not perfect, I get a figure of 167 hp. That is based upon curb weight, plus the weight of any passengers and cargo, and the weight of any gasoline thats in the tank. It then measures the acceleration to a set speed in a fixed gear, typically 2nd. That is a calculated output at the crank, so obviously there is a significant margin of error.

The difference is quite noticeable, this van is respectably quick. Already at lights I've found it is able to actually out accelerate most cars, not just older cars. This evening I outran an aggressive V6 Mustang. It will do 0-60 in about 8.8 seconds. According to Ford's specs for that year 0-60 is about 9.2 seconds. But I do also have a freer flowing muffler, and the intake has had the baffle/intake horn removed. The exhaust on this is 2.25" from the cat back, unlike the stock which runs a 2" from the cat back, through a stock muffler that is between 1 3/4" or 1 1/2" inside. I could swap out the cat setup for the one off my '97. My '97 has a custom made cat and y-pipe that was designed to flow for heavy towing. It is a direct bolt on for any other year, just have to plug the rear sensor port for a '95 or older. It runs dual 2" head pipes into a proper flow oriented 2.25" y-pipe. and dual 2.25" actual high flow cats (same type I run on my turbo T-bird). It worked well on my '97, and it should be an easy swap. I still need to finish gutting the '97 so I can send it to the crusher.

 

with my '86 and '92 3.0 Aerostars I could leave BMW, Mercedes, Hondas, and many other cars in the dust at red lights.

That has not been the case with my '97 4.0 liter, I'm sorry to say.

Seems like by 1997, the Aerostars lost their horsepower instead of becoming better.

This does not mean that my '97 is a slug, it's just not as fast as the other two.

 

Thats because your motor is trashed. My '97 was pretty quick. The '97 picked up 10 hp over the previous years, and a noticeable amount of torque. Thats part of why I elected to use the '97 cam, it has a different profile that was part of the recipe or more performance.

Sad truth about these 4.0L (and the 3.0L for that matter) motors, if you have more than 120,000 miles, your exhaust valves are already trashed. Every one I have ever pulled apart was basically more expensive to repair than to replace the entire heads.

 

I wouldn't know about the exhaust valves or the motor being trashed, the motor has power and a very nice "roar" when I step on it, just not as much "fire" as the 3.0 motors as I remember them.

 

I would know, I've had enough 4.0Ls and 3.0Ls apart. By 120,000 miles they are already going downhill. I'm willing to bet a leak down test would show low compression. Before I obtained my '97 4.0L Aerostar, it belonged to my brother. It blew a head gasket because he ignored a coolant leak problem. The engine had 118,000 miles. When I pulled it apart, all 6 exhaust valves were sunk so far into the heads that they wouldn't seal anymore. The engine seemed to run fine otherwise, buts thats only because everything was worn out evenly. The exhaust seats on these motors are basically worthless. Ford didn't care about it beyond 100,000 miles.

The 3.0L motors are gutless, and if your motor doesn't make a 3.0L seem slow, they your motors is either completely worn out, or your need a major tune up.

 

Nicely done. You're either persistent or stubborn to do this kind of stuff. I've done it on other cars, but the one thing that discourages me from doing it on my more modern Fords is that I have to take apart the A/C system, per the factory manual.

Did you put an adapter for an oil cooler on it? I don't remember my '95 4.0 having the filter stick down at an angle like that. But, it's been gone almost ten years now.

How did you find someone to make a bigger radiator? Is it the same type of construction as the stock radiator (plastic tanks, Al core)? Do you have a picture?

What rebuild kit did you use? Most if not all kits I've seen don't have the lifters and the lifters are $65 a pop. That's crazy. For an engine with millions of copies running around, lifters shouldn't be that much.

 

The AC system did not need to be taken apart, only pulled out of the way. However the engine was raised in from the bottom, rather than through the front. If you went through the front, then yes, the AC would need to be removed.

That is the stock oil filter adapter, all 4.0Ls have them the Aerostars have a longer one at a different angle than the Ranger/Explorer. Otherwise your oil filter would go straight into the side of the motor and would be impossible to change with the engine installed.

The radiator is universal all aluminum welded radiator and was purchased by core dimensions, then it had mounts welded on so that it installs like factory. The welding/fabrication was done by a local company that makes/welds aluminum radiators for motorcycles and race motors. I had to supply the radiator itself, they did the rest.

I sourced the rebuild kit through my machine shop and it included all the standard parts and only extra parts that we specced. I did NOT order lifters, they are optional and only need to be replaced if the old ones have an issue.

 

Anyway, completed my trip without any real issues. I did have a CEL com in on intermittently, I'm pretty sure the MAF is contaminated, its one of the parts that wasn't replaced, and the issue seems consistent with a MAF problem, but it really didn't cause an issue other than triggering a CEL. Other than that, everything worked flawlessly. Drove a total of 1400+ miles.

 

Well, just an update. Since my last post here, I have had some other issues. Firstly, there was a compound issues, where several problems were going on at the same time, which made it harder to fix and diagnose, but those issues are figured out now.

Firstly, the fuel pump died on me. Basically the old pump wouldn't prime when you turned on the key. The old one was getting noisy, so it let you know if it was running or not. So I used a pump I had bought a while ago. Since Motorcraft pumps are expensive and hard to come by, I bought a Denso one. Now I have a new and quiet fuel pump.

Next, the pigtail connector for the crank sensor went bad. I ended up replacing the sensor itself, and the pigtail. That fixed that issue, but that was a pain to figure out. Then the problem came back again, and so I replaced the entire wire, and found out the old wire had been repaired before. Now its an all new wire, and that should prevent any future issues.

Finally, I did end up having a flaky EDIS module. It tests good, but when we recently drove up a canyon, we parked and went for a walk. When we got back, the van wouldn't restart, and it was not a connection problem. After having the hood open a few minutes, it started, but ran really rough. So I decided to try to drive it, and maybe by getting it moving, it might clear up, so we closed the hood. With the hood closed, it didn't run long enough to get out of the parking lot. So I grabbed my spare EDIS module, quick swapped it, and viola, it fired right up and ran fine. It appears that the old one might be getting weak and heat sensitive.

Anyway, I'm going on another long road trip this coming weekend.

 

Well, I completely my road trip without any further issues. Everything worked good.

 

What's an EDIS module, and do always carry a spare when you go up the canyon?

 

An EDIS module is what controls the ignition on 4.0L Aerostars, Rangers, and Explorers.

No I do not normally carry a spare. I only had a spare because a technician that worked on the van misdiagnosed a misfire issue as a bad EDIS module. Because the new module didn't fix it, but couldn't be returned, I had a spare.