Remanufactured engine


Can I or should I expect a remnufactured engine to run like “new”?


I got one and it does, but the things that you attach to the engine, like the carburetor or FI, distributor or other ignition and the accessories like water pump, alternator, can drag it down.


That depends. Exactly what is it doing or not doing and what kind of car/engine are you talking about?

If you take a new engine and change over old, dilapidated plug wires, 200k mile fuel injectors, lousy EGR valve, leaking fuel pressure regulator, or defective/worn sensors and widgets from the old engine then it may not run any better than the old one.
If the old engine was running lousy due to a clogged converter then the new one will be no better.


This engine is a 4.2 L six cylinder for the Ford F-150. It is the fourth engine to be put into the truck since 1996. I got one of the first '97’s to roll off the assembly line. After 800 miles or so, it was necessary to replace the original engine. The second lasted for a little over 80,000 miles, when one of the piston rods warped and began knocking. Engine number three had a bad shake at 1100 rpm’s, so they put in the fourth one, which is also running rough. The truck still only has 83,000 miles. Should a remanufactured engine run like new, or do I need to settle for the performance of this latest replacement?


A remanufactured engine should run like a “new” engine. That assumes that all the accessories attached to the engine are in good condition, and that the ignition system and fuel system are working correctly.

The “remanufactured” part is just the engine internals, not everything that hooks to the engine.


No doubt your second engine (first replacement was a new engine. The quality of remans vary by the rebuilder and the quality of the core they use. Some use only good quality cores and rework or replace almost every internal part. Others don’t do any more than absolutely necessary to get the engine to run.

You or your mechanic may want to switch suppliers. The reman should run as good as new, but probably won’t last quite as long as a new engine, but should be cost effective when compared to a factory new replacement.

You (or your mechanic) should make sure that the roughness isn’t due to something external such as a plug/wire or injector. Also check the rocker arms for tightness/adjustment. Watch the rockers while the engine is running to check for a flat cam lobe.

 I was curious as to whether or not the first replacement engine on this vehicle would have been a new "crate" engine or a remanufactured one. I  leased this truck at first and contracted for a new vehicle and a Reman at that time would constitute a fraud on Ford's part. I assumed that they replaced the original engine with a new one, but am not sure whether I got a "new" vehicle. Anyone know what Ford's policy might have been at the time? Any guesses?


There’s a lot of the story missing here. There is no way on earth 4 consecutive engines have been bad, reman or not.

A rod does not “warp” and cause a bearing knock.

If the engines are being replaced solely on the basis of running rough then someone has no clue.

I would hate to even venture a guess on this one as there are too many unknowns, but offhand this sounds like a crummy plug wire or something that is being transferred from one engine to the next.

Who’s doing all of these alleged engine swaps? A Ford dealer?
Most importantly; who’s paying for it? FOMOCO or the dealer is not going to pay for 4 of them.


I’m with OK on this one.

What EXACTLY was replaced??

A remanufactured engine does NOT usually have new injectors, distributor, wires, plugs, intake manifold, sensors. All those come off the old engine. So if any of the old parts were bad then putting them on the new engine could make the new engine run bad.

One engine I rebuilt about 20 years ago I did exactly that. But I knew it would have some running problems. But I didn’t want the headache of troubleshooting EVERYTHING all at once. So after I got the engine up and running, I replaced the distributor with a new electronic ignition system (the old one used points)…With all new wires and plugs. Then I replaced the intake manifold and carb with a fuel injection system (aftermarket system made by Holly for small block GM V8’s made in the 60’s.). Then I replaced the exhaust manifolds with Eldebrock headers.

When finished it purred like a kitten…and was extremely nice on the road. More power and BETTER running then new.


Not knowing the total story behind your truck I can not say for sure but I can speculate based on my experience. In 1996 ford started producing the all new 1997 Ford F-150. At the Ford garage I worked at we saw a 5% failure rate on the 4.2 liter engine. Usually within the first 1000 miles they would begin consuming 1 quart of oil every 500 miles. We were actually delivered 2 that smoked so bad driving off the convoy truck that the motors were replaced before being put out for sale. The apparent problem with these motors was faulty rings. I say apparent because we were not allowed by Ford motor company to disassemble them. They were sent back as a complete unit to be torn down for inspection.
The policy that we were given at the dealership I worked for was to order a new motor from FOMOCO. This motor was shipped to the dealership as a mostly complete unit. The accessories and the fuel injection was the only thing that needed installed. It is my assumption that yours was done the same way.
As far as the re-man motor you have now it sounds like you have a sensor fault, a fuel delivery, or an electrical issue. If you transfer a faulty component to a new motor it will run bad. A quality shop should be able to diagnose this issue and repair it. Although the engine may not run like it did in 96 due to wear of external components it should be close.



 I guess I left out a lot of details about the vehicles history so here goes.
 I leased the vehicle in June of '96 and after about 800 miles or so, the engine developed a knocking sound and the original dealership decided to replace the engine. I'm not sure whether this would have been a "new" crate engine or a remanufactured one, and really don't know how to find out.
 In any event, Ford issued a recall in July of '98 to replace the front engine cover gasket because coolant was leaking into the oil ports and causing damage to some of these engines. As I said before, it was a 4.2 Liter 6 cylinder. Shortly after that first recall, a second one was issued about the same problem. Mechanics had complained that time allotted for the procedure on the first SPB did not give them time to properly clean all of the ports before reassembly. I found out about this second recall at the Talk Back! Fight Back! site where I found hundreds of people having the same problems I had experienced. I never got the second recall notice and never had the procedure done.
 Over the years, I have experienced a complete depletion of the coolant several times. It had happened five or six times, sometimes only weeks after having refilled the reservoir. I took it to the dealership and was told that this was normal. Normal!Mind you, there has never been any evidence of a leak. No signs on the engine, on the garage floor, or on the driveway, and no warning that levels were low until the engine temperature warning light came on. The engine was burning that stuff. 
 There was one occasion,this past winter where I had no heat. I went to the dealership and was told that I would have to replace the heater core, something I could not afford at the time, but when they replenished the coolant, lo, and behold, I had heat.That second engine used a lot of coolant.
As time went on, the engine developed a ticking sound, then a rapping sound, then a clunking sound, which led me to have the engine replaced. One of the engine rods had warped and was knocking against the block, I was told. This truck still only has 83,000 miles on it!
 The remanufactured engine that was installed back in April of this year had a bad vibration at 1100 rpms. When they did the job, a new waterpump was installed, new belts, new spark plug wires and plugs, and the core came with a new intake manifold.
 I took the truck into the dealership to have the vibration checked out. The lead mechanic test drove it and immediately said there was something out of balance in the engine and that it would have to be replaced.
 Engine number four has all of those new parts I mentioned earlier plus new injectors. Now when I drive my truck, this "new" engine has the same vibrations at 1100 rpms and additonal vibrations at 1600 rpms. Can this be right? Am I expecting too much , or should this engine run like new? What should I do?


Why do you still own this thing?

 I have kept this vehicle because, when the lease was up, I knew I could not have found a used vehicle that I knew had been cared for as I had cared for my truck. Not for the money. The truck has been garaged all these years, the body is in excellent shape. I own it. No payments except now  the bill for the remanufactured engine and about a thousand dollars for brakes and replacing all suspension parts. I could not have found a used truck for the money, at least I don't think so. The reman has a 3 year 75,000 mile warranty, and the mechanic who did the undercarriage work will stand by his work for two years. I guess dealing with the known evils of this vehicle as opposed to the unknown evils of  someone else's used car seemed better to me


Did all these reman engines come from the same source? I guess I would just keep taking it back until they get it right, or until the warrantee expires. However, I’m not sure I would want to keep it after the warrantee. A properly reman engine should run like new, but not all reman engines are created equally.


I beleive that the original engine was a new one. The car was under warranty and Ford is the one that pays for that not the dealer.

If you are going to keep the truck, why don’t you try new short block and but all of your existing accesories on it. At least this way you know the rods bearing and pistons are all new.