Known issues with Ford 4.2L V-6?

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A co-worker has a '97 F-150 with the 4.2L V-6 with straight drive. It's an extra vehicle at the house; she normally drives a 2010 Fusion Sport V-6. She had the F-150 at work the other day and started it and heard a gawd-awful clanking noise from the engine. Turned it off and called her husband. He said it would probably make it home, and it did. They went to start it the next day and it turned over and immediately seized.

The truck only has 75,000 miles on it, and it's been serviced with Mobil 1 every 10k miles since new.

I'm sure it's not a lubrication-related failure. And to be clear, this is not a Mobil 1 hate thread, please don't turn it into one; I use Mobil 1 myself.

Are there any "bad genes" with this engine like known valvetrain problems? I figure it probably dropped a valve by the description of the symptoms. At first I would have suggested possibly a cracked flywheel or something else external, but it's indeed terminal.

Do these share the same weird spark plug thing that the Modular motors have? Even with those, if you had a bad one wouldn't you sense the loss in power? She said the oil pressure and water temperature gauges read normal on the way home and the engine had normal power. It was just clanking bad all the way home.
 
FIL has one hauling oil drums in severe service in the Caribbean. Can't be that bad - has the original AT at over 100k when their 4 cyl accord lost its AT at 28k.
 
A buddy of mine at work had this exact truck. He took very good care of it. I don't recall if it was a cylinder head or head-gasket issue, but out of the blue, so much coolant got into the crankcase, the engine spun a bearing and was junk around 70Kmi.

Joel
 
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I'm thinking head gasket too. Probably hydro-locked, hence the seizing on turn-over.

And the Modular spark plug issue leaves you with a driveable, albeit, loud and down on power vehicle that can most certainly be fixed and cannot cause engine failure. It is just extremely annoying.
 
The timing cover gasket was the weak point on the early 4.2 engines, and even had a service campaign/recall #99B29 to adress the issue. The gasket would fail and fill the crankcase with coolant.
 
The '97-'98 Ford Essex 4.2s had HORRIBLE gaskets. Pretty much all of them. Head, timing cover, intake manifold...etc...

They fixed the gaskets and just that little fix transformed the 4.2 into a solid engine. Certainly as good as the 3.9 Dodge or 4.3 Chevy. But man they had some gasket problems in the beginning.

What's the dipstick look like? Is it full to the top with what looks like melted chocolate ice cream? Intake manifold filled up the engine with coolant.
 
I work with a guy who has a '97 F-150 with a knocking 4.2 sitting behind his house right now. I noticed his truck was low on coolant and mentioned something to him about it before it started knocking, he seemed to think it was fine so I left him alone about it. After it started knocking I did some research online and like others here mentioned it begins with the gaskets. From what I remember either the intake manifold or head gaskets leak a bit of coolant into the cylinders overnight and partially hydro-lock the engine and the knocking comes from one of the connecting rods bending and allowing the piston skirt to hit the counter weights on the crankshaft. Like OVERKILL said it probably hydro-locked the next morning when they tried to start it again. It might be salvageable with all new gaskets a new con-rod or two and a weekend of wrenching if they're mechanically inclined. But like my buddy found out it can get pricey to fix if you can't do the job yourself, that's why his truck is still sitting behind his house.
 
Exactly one week ago I was doing Craigslist searches on this very truck/engine combo. I didn't know about these issues, but I called one person (who advertised in the owner section, but actually was a dealer) who said, "Yeah, I just took this truck in on trade. It needs an intake gasket, but otherwise it's great!" ha ha, I was tempted, but I turned it down. Now I'm glad I did!

So I assume that the 4.6L V8 is OK in these late-90s F-150s? I would assume that they're fine, but I guess it doesn't hurt to ask.
 
The 4.6 is bulletproof in these trucks. I owned two - a '97 and a '99. Sold the '97 with 163,000 on it, only to upgrade to the '99 which was a 4x4. The engine had never had an issue other than regular maintenance. I sold the '99 with 193,000 on it as I needed more cab space. The engine ran like a top.
 
The Ford 4.2 V6 also has a "Cam sync plug" which takes the place of an ignition distributor. A failed one can cause stalling, or a noise that sounds like a failing serpentine belt.
 
I'm no fan of Fords in general, but I've seen these 4.2s take some serious abuse that's killed plenty of 4.6s and 5.4s a lot faster in the same fleet. If you fix this thing, my advice for living with one of these motors happily:

-If the CE light comes on because the cam sensor broke, replace it right away or it'll end up ruining the synchronizer.

-Don't run more than 3 quarts low on oil for long or it'll ruin that same cam sensor synchro.

-If you have a mysterious unexplained multiple-cylinder misfire or excesive pinging, clean the EGR passages in the intake. You'll have to pull the EGR valve off, but not the intake. Just jam a rubber hose in the hole, fill the hose with solvent, wait a few minutes, then blow it through with compressed air.

-If you have a metal intake manifold, don't leave your coolant in there for more than 4 years at a go. Manifolds are expensive.

-There may be a rubber boot where (I think it's 3) vacuum tubes get vaccum supply from the upper intake on the passenger side. If it blows off unecpectedly you need to replace the ignition coil pack, then stick the boot back on.
 
Originally Posted By: artificialist
The Ford 4.2 V6 also has a "Cam sync plug" which takes the place of an ignition distributor. A failed one can cause stalling, or a noise that sounds like a failing serpentine belt.


my 04' Freestar with the 4.2 is squealing like a stuck pig, rpm at idle is fluctuating and then sometimes the engine dies, mostly will restart but sometimes not

by the sounds of it the cam sensor must be the culprit but how can something squeal like that and not be dumping tons of filings into the motor

I am not driving it, it died on me at a stop sign in town and then restarted and drove 20 miles home but when we went to go the next morning it was giving the above symptoms so parked it until I sort this out

so what about the possibility of a lot of shrapnel in the engine or at the very least a lot of filings ?
 
Originally Posted By: farmerjohn

my 04' Freestar with the 4.2 is squealing like a stuck pig,

by the sounds of it the cam sensor must be the culprit but how can something squeal like that and not be dumping tons of filings into the motor

so what about the possibility of a lot of shrapnel in the engine or at the very least a lot of filings ?


Chances are, the engine is fine. I don't know your mechanical ability, but these aren't too hard to replace. They sell an "alignment kit" that has a bunch of plastic buttons to help you to install it properly, but if you install the new one and line it up exactly like the one you took out, you don't need the plastic alignment button.
Some of the replacements come with the button, but the Motorcraft replacement does not. By all means, spend the extra money and get the Motorcraft replacement. Some of the aftermarket replacements are good for only about 5K-10K miles and the cheap replacements will fail without warning.
 
well the job is done and once the cam syncro was out it seemed to be fine but a lot tougher to rotate than the remanufactured Spectra Premium replacement (42 bucks) OEM Motorcraft $332

in a Freestar the trick is to remove the wipers and the two plastic pieces that form the cowling over the motor, then the PS pump and then using a goose neck pry bar gently coax the steel coolant bypass pipe out of the front of the block beside the cam syncro

It was about a four hour job start to finish
 
Several years ago, the company van 97 E150 with the 4.2 V6 started knocking badly out of nowhere. I believe it had around 135k miles on it and was sold to a repair shop that was going to replace the engine.
 
Originally Posted By: farmerjohn

in a Freestar the trick is to remove the wipers and the two plastic pieces that form the cowling over the motor,


Did you replace the back three spark plugs while you were there? About the only way to get to the back three spark plugs are to have extremely long, thin arms, or to remove the windshield wiper assembly. I don't think I've ever seen arms long enough to do it...
 
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