The Ford 4.6 liter V8.

[piece-it pete]

Gotta love V8s!

After 3 different 5.0s' ('84, '87, and '90) in Grand Marquis I graduated to a 4.6 in my '97 three years ago.

Great engine imo so far.

But two things I thought I'd mention, as there has got to be a number of folks on this board that have this engine in Mustangs, full size boats like mine, trucks, etc, so I thought I'd start a thread.

1st, most 4.6s' made from 95-97 have a SERIOUS FACTORY DEFECT, as in the intake manifold has an integrated pipe that moves coolant from one side of the engine to the other, that CRACKS. This includes Cougars and Tbirds as well as the abovementioned.

Bless it's corporate soul, Ford recalled all fleet vehicles (cop cars, taxis, etc) but left us lowly consumers holding the bag. Sure enough, mine cracked (you'll know it - coolant pours out like crazy from behind the alternator), 1st my local Ford dealer wanted $1700.00?! to fix it. The part costs almost $600.00!

Well, call Ford, argue, argue, loyal Merc cust, etc, long story short $600.00 out the door. Still not chicken feed, but not bad for an at that time 6 year old car. Anyway, you can tell if it's been changed thusly: the pipe that breaks runs across the front of the intake manifold, right behind the alternator. The "bad", original one is black plastic. The "fixed" one is cast metal, aluminum or magnesium, not integrated into the manifold. Take my word for it: check! After '97 the correct manifold became standard from the factory.

2nd, last night suddenly it would not idle. No rough running, etc, it would start and quit immediately. Did a quick search on "crown vic*" "won't idle" and after about 5 minutes of looking found a mustang site that had the goods (love the internet!!).

Called the IAC (idle air control), this part does god-knows-what, but if it sticks you get no idle (and no check engine light - no codes to help!). Reading around it is very common for it to stick or fail at about 75,000 miles, mine at 82,000.

On many it looks like a little starter, two bolts holding a can, with an electric connection coming off the end. On my car it was attached to the backside of the throttle body, with a large vacuum hose coming out the top, came off in 3 minutes.

Cleaned with carb cleaner, let dry ten minutes, shot a little WD-40 into it, reinstalled and pow! runs great.

That's it for my experience, although I think the power steering pump is about to fail, BIG surprise on a Ford :rolleyes: . Also, I had a Ford tech tell me to be sure to keep the oil changed on the 4.6, if you do it'll "run forever".

Anyone else have any comments/hints/tips on the 4.6? Any easy power boosts or issues to look out for?

Pete

[Eric H]

Hi Pete,

The only other issue I can think of on the 4.6 and it's siblings is the spark plugs.
be sure they are kept torqued properly, i.e. kept tight.
There is only about 3/8" of thread on these and if they get a little loose they'll pound themselves out and eventually pop out, taking the threads with them! Nearly impossible to fix without pulling the head (and the engine)

These are great engines, I work for a Fleet with hundreds of them and the only serious failures are when they get run out of oil!

[spkrman57]

Pete,
Glad you got the "Land-Yacht" running again!
Ron

[Jstas]

Working at Pep Boys, I met many people with the mod-motors in thir work vans and trucks and racking up well over 150,000 miles without any problems at all. Only one guy had issues and he never did any maintenance on the vehicles.

As long as you perform your regular maintenance and checks on any 4.6/5.4 V8 or the 6.8 V10, they will run a good long time before needing major engine work. Save for the coolant pipe issue mentioned above and the spark plugs tending to want to pop out.

[Sandy G]

I wonder if the 6.8 L V-10 in my Excursion is really just an overgrown 4.6 or the 5.4 V-8 ? My tugboat has 81 K miles on it, & still runs like the proverbial top.-Sandy G.

[Yamaha B-2]

Same for the smaller 4.0L V-6 in my Explorer. I like it a lot mated to a 5-speed automatic transmission and a 'real' 4-wheel drive with a low range. Decent mileage at 20mpg on the highway and pulls us up and down the local beaches through deep sand in low-range 4WD without a thought. I'm very pleased.

[Jstas]

I wonder if the 6.8 L V-10 in my Excursion is really just an overgrown 4.6 or the 5.4 V-8 ? My tugboat has 81 K miles on it, & still runs like the proverbial top.-Sandy G.


The 4.6/5.4/6.8L engines are reffered to as "mod motors" because they are a modular design. Each bank of cylinders, except for the ends, are made up of parts that were made with modular casting. Your 6.8L V10 has 10, .68L cylinders. The 5.4L V8 has 8, .68L cylinders. The 6.8L V10 is a 5.4L V8 with two extra cylinders added into the middle. They could make an 8.1L V12 or a 10.9L V16 and so on. They just have to take the blueprinted design and add as many cylinders as they need to between the two end pieces in the design. The computer builds the casting form and then the engine cast and out pops a a V...whatever sized engine and it cost them 1/20th of what a normal, new engine development process would cost. On top of that, it provides repeatabilty which improves quality control which als improves reliability and durability. Design changes are easy to implement and the real nice thing is that it's easy to make parts for aftermarket stuff.




As far as anyone wanting to make quick power with the Ford "mod motors", they respond disgustingly well to forced induction with either a supercharger or a turbocharger. Just make sure your setup is intercooled and you put in an oil cooler and a transmissino cooler for automatic equiped vehicles and you can pick up an easy 100-120 horses with a pretty low 6-8 pounds of boost. The kits can get pricey but when you look at how much power you gain compared to what they cost, they are a bargain. Other ways to make some quick power are to install a new exhaust system, get a reprogrammed computer chip and a bigger throttle body and injectors. I've seen cars pick up 30-80 horses with just those modifications. Start out with a Mustang engine already pumping out 300 horses and you can hit 400+ easily with very little work and never have to open the engine. The only issue is that the stock blocks won't support crazy amounts of power. The 4.6L will only hold roughly 550-600 horses so if you are going hardcore on the power levels, you need bottom end work. The 5.4 will hold close to 800 horses and then they need help too. The V10's are not really geared towards high performance but if you wanna make power there, the will make gobs of tourque so they would be good towing engines.


Oh, the difference between the cylinder volums of teh 4.6L vs. the 5.4/6.8L engines is a taller deck heigh on the 5.4L/6.8L engines as compared to the 4.6L. That is where the .11L of extra displacement per cylinder comes from.

[THOR]

Well I know from checking on the net after it happened to me the day I got my 2001 Expedition (dealer covered it) But 4.6L and 5.4L triton v8's from I believe 2001 on down are notorious for the coil packs going bad. Something to do with the hose that goes to the heater core leaks onto the coil packs. They corrode and fail, my mechanic told me one time they couldn't remove the spark plug it was so rusted in there. Loss of a coilpack causes rough ididling, real rough, and loss of power and each one is like $150 just for the part. My boss has a 96' expedition and he lost too coilpacks at 50,000 miles his has over 100,000 with no problems. Mine had 50,000 miles on it the day I got it and lost 2 coilpacks. If you look online some folks have had much worse and more frequent problems with them.

[Jstas]

that's not the coil packs going bad dude. That's the coolant crossover hose leaking and causing the problem. I haven't heard of any coil packs going bad on engines without the crossover pipe or at least the revised crossover pipe. Fix the real problem, the leaky or bad coolant crossover pipe.

[THOR]

Right but the leaky pipe is what causes the coil pack issue that is way it is only up to certain years then I guess they moved the pipe so that it didn't crossover the coil packs. No even sure if leakage is the problem might even be caused by condensation dripping down. Do a search it is a very common problem on certain years of the 4.6 and 5.4 Someone mentioned a kit you can buy to prevent it from happening on one of the F-150 forums.

[Eric H]

The coils do go bad from time to time, I wouldn't call it a problem area though.

Coolant from a bad intake or rain water (on the Econolines & Expeditions) can cause a problem but just as often they just seem to go bad for no apparent reason.

We buy em from NAPA for about $30

[Sandy G]

My V-10 doesn't really need any more juice, it's fine the way it is, but woe be unto him who bought an Excursion w/the gas V-8. I think it would be a slug-mine weighs 7400 lbs, empty. It NEEDS a V-10.-Sandy G.

[THOR]

I believe it Sandy, after driving a cherokee with a 4.0L straight six, my Expedition seems underpowered. The Expedition makes my old Cherokee seem like a Corvette. Of course the Expedition is supposed to feel like a tank ;) I can't imagine an Expedition with a 4.6L or an Excursion with a 5.4L

[bgadow]

I knew this Ford mechanic, who bragged about being the best there ever was, he only drove Chevy's. He said these engines were junk, that he was replacing them daily, as fast as he could go, and that he'd love to rebuild them but they were so junky it was impossible. His boss was lucky to have a mechanic so good that he could replace all these trashy Ford junkheap motors. No, I don't really believe what this guy said. My only bad experience is with the V6 version (4.2L), I think every one of them thats been in our shop blows blue smoke & rattles on startup.

[madpioneer]

Keep the throttle body and plenum clean. Spray carb cleaner or equivlent at routine intervals. 4.6 Motor is notorious for carbon build up there from back lash of the RGV. Will cause power robbing condition slowly over time almost unoticed. Eventually will trigger 'Check Engine' light due to bad air/fuel mixture/flow. Not sure this is the same hose mentioned before. But there is a hose that runs thru the block carrying coolant. It comes thru the front of the block. It has to be eventually changed or your gonna have problems. I believe the manifold must be removed to get at it. Cheap part to replace but labor is the killer! 'Bar Links' at the tie rods on the front, their bushings go bad around 75,000 miles. When you hit a bump, pothole, crack in the road the front end has a clunking or clinking noise, very annoying. You can actually bounce the car with your own wieght while the car is parked and hear the wonderful noise. Will drive a person crazy if they are not familiar with this problem('What the h*ll is that noise!?').Bar links are cheap and you can install yourself in less than an hour!
If you plan to drive it over 100,000 miles do your self a favor change the coil packs. Especially if you travel alot you will thank yourself later. Heat alone breaks em down. At around 75,000 to 80,000 when you go to change the plugs do the plug wires and coil packs at the same time. Coil packs are around $40 each. Big long lower coolant hose will run you around $65 is really long, budget for that, it ain't your typical $15 lower hose. Horns are located in the worst location. In front of the driver front wheel. Water from the road spalshes up and causes horn operation loss until it dries out. Remove the connector bend the contact blade on the horn side to make maximum contact with connector lube with de-electric grease or equivilant. Re-install connector to horn. Then seal off connection with electrical tape or other that can water-proof the connector!
All this is based off my 1995 Grand Marquis experience.

[piece-it pete]

Well my IAC went, I couldn't remember what it was so I had to search for this thread, I figured I'd update my Ford experience.

Apart from that the engine is doing fine at 113K. (Fine?! I love this thing! Uncomplaining power.) I've changed belts plugs wires etc but no problems there.

The tranny slipped on my way to the last 'fest (it was pulling some massive weight) for the 1st time and since then hasn't been right, it's thunky and more stupid that it was, but it still works (I've been planning on changing it all summer :( ). It's my understanding that perhaps one should figure on changing these occasionally.

Panther-platform specific (full size Ford cars) I had to change my whole front end 'cept for the idler arm. You can get super cheap parts for these but I advise against it - I got a faulty tierod end and upper ball joint. The good news is, this car is by far the simplest easiest car I've ever worked on. Remember sitting around fighting a part saying the designers should be forced to change the screwed up parts themselves as punishment? Well I guess Ford did it :D .

I still rec these cars.

Pete

[Carmine]

How old is your trans fluid? The heat of towing can break down the additve pack in the fluid and produced a harsh shift. Flush it before changing the trans.

Also, never tow in OD. I'm not saying you did, but just mentioning it.

I have a friend with a '95 Grand Marquis, that has the "touring pkg"... Dual exht, suspension upgrades, etc. He loves the car, especially on long trips.

BTW, he's 33, so I guess that really throws the demographics for that car! :D

[piece-it pete]

Also, never tow in OD. I'm not saying you did, but just mentioning it.

Oh, I dodid it, all right.

Yep my next one will be the "Performance and Handling package", any full size Ford product with daul exhausts has it, the old Police Interceptor package, standard on Lincolns. Plus based on this thread the next one will also have a supercharger :banana: . Although it'll be a few years - the next car is the SOs' pick :( .

I'm 39 and this is my 4th Grand Marquis, I love them.

Pete

[Sandy G]

I'm a Kraut, so I over-engineer everything, but I've always felt you should get the "heaviest-duty" springs, shocks, tranny coolers, bigazz alternators on a car that they offer, on the theory its better to have it & not need it, than to need it & not have it...

[alexkerhead]

I have a 4.0L V6 in my Explorer, but after 180K miles, it still runs like new, with NO repairs done(cept plugs, wires, oil, etc.). This is mostly city miles too.

I don't have a ford v8 though. :(
I have a 5.0L chev v8 in my Alabama cadillac though(83' silverado)
Peice of crap engine though. :(

[Brockster]

I used to drive for an airport shuttle service that had brand-new 2003 Crown Vics. When I left there slightly after ONE year, all of the Vics (that hadn't been wrecked) had well over 100K miles on them after starting a zero miles. They seemed mostly bulletproof and they were operated 7/days a week for 20 to 24 hours a day.

They only other thing to watch out for is that if you have the climate control with the digital readout, a board or black box fails in that system that directs the louvers in the dash. If only the defrost vents work - no matter what the ducts are set on - then that board has failed and it will not be covered under warranty. It's about a $600-700 repair.

I love the Crown Vics, :thmbsp: and used to own an '85. I drool over that kcpolicecars.com website that sell mostly the P71 (cop car version - look for P71 in the VIN) Vics.

[piece-it pete]

A little more panther-specific stuff:

I finally had the tranny changed (didn't do it myself for once), just to a junkyard one with 58K.

What a difference! But then, I've found the oil pan is rusty and starting to seep. :(

And Ford seems to like the oil pan shaped over the front crossmember, so to change it you have to lift the engine. :cry:

Now at 130k, I'm about to change the universals (thunking from drivetrain) and front wheel bearings (steady slight wobble from front passenger side, more than just rotor).

I'm going to go ahead and change the front rotors too, again. I'm learning the fix-it-20-times way that the $15 import rotors are junk - my pads outlast these! I'm going to bite the bullet and try Summits house brand, vented, crossdrilled, etc.

And the stupid front stabilizer pins (bar link), again, again, again. Same story with cheap parts. I am sick of changing these.

Overall though a comfortable good running (and long paid for!) rig. Body wise I'm starting to show a bit of rust on the drivers side fender right over the tire, which I see on other panthers my cars age (1997), inside door bottoms, and the headliner's starting to peel at the back.

Pete

[6thumbs]

I,m driving an 87 townie bought it with 63k burned a quart every 3k then and with 198k still only uses a qt every 3k ,,been a GM man my whole life but that town car has turned me around,,it,s too bad the minnesota winters have killed the body

[soundmotor]

IMO the only mistake Ford made when they introduced the mod was to introduce it as a 4.6 when they owned the "5.0" franchise! I just cannot believe that there was no way to get another 10% displacement from somewhere.

[gadget73]

the 4.6 modular is an awesome motor, just expensive to fiddle with. They run and run for a long time with minimal fiddling though.

[Twenty20Man]

I have a Lincoln Mk VIII and it has the 4.6L 290something hp and that car is wicked fast, handles like a dream. I love it. great great motor don't care what anyone says about it.

[speakerlust]

I've got a 93 Grand Marquis that I have beat the holy hell out of, Got er to the wood daily at 80+ miles an hour. Sliding around corners, smacken er to the floor and blowing past people on the freeway. 178,000 miles and purrrs likes a kitten. Can't even feel it running, let alone hear it. I heard a couple of pully's squealing last spring so I pulled them off and pounded new 5 dollar bearings in them. I cannot believe what abuse this 4.6 takes! My previous vehicle was a one ton diesel cargo van, so you know that I expect alot out of a vehicle, and this beast delivers.

[1 Starr]

In Michigan I've seen the oil pans rot rust holes. Have to love road salt. Cheap metal dont help. The intakes leak coolant. The crankshaft position sensor wire harness rub thru by the timing cover causing the engine to cut off and back on- bucking on acceleration.The 92 to 95's seem to suck oil like a pig. If you hold the throttle at 1500 rpm for a few minutes,Then the pipes turn into mosquito chasers. The O2 sensor harness rubs on the converter heat sheild causing a Check engine light.The EGR valve was a royal pain to change with the tube cracking and setting low flow codes, Serviced thru the right front wheel well. A real riot. Clogged EGR ports under the throttle body.The DPFE sensor and the hoses fail. Collasped PCV hoses. Mass air flow sensor dirty or replace. And the best is the rocker arms flying out and bending the valves. I've seen several 4.6, 5.4, And the V-10 do it. Also The right side camshafts wore the lobes off a few of them in the early models. No grease fittings and the ball joints squeak on turns. The good is the smooth ride and the low end torque the bodies seem to hold up well. I work on several Fords and truthfully the 351 Windsor and the 460 V-8 were better in my opinion.Old school.