1998 Ford Expedition 4.6 liter v8 question

Status
Not open for further replies.
Joined
Sep 1, 2008
Messages
5,947
Location
Southeast Texas
Just got this 1998 Expedition and I like it, but its a real dog performance wise. The 215 hp 4.6L V8 is anemic. Any tips from you Ford guys out there for a simple, cost effective performance boost? Thank You!
 
Originally Posted By: gfh77665
Just got this 1998 Expedition and I like it, but its a real dog performance wise. The 215 hp 4.6L V8 is anemic. Any tips from you Ford guys out there for a simple, cost effective performance boost? Thank You!


Simple, yes.
Cost effective, maybe.

When looking for performance modifications I look at the "big 3" first for most vehicles.

1)CAI
2)Cat-back exhaust
3)Tuner (Superchips, Diablo, etc.)

While these will increase your performance the question is whether or not the money you spend is worth it, some people feel it is some do not, it's pretty subjective. If you feel up to the task you could probably engineer your own CAI using pvc pipe for under $150 (filter included).
 
Last edited:
Wait you forgot to mention your mileage and how well it's been maintained!

Step 1, change all fluids.
Step 2, change the spark plugs, plug wires, distributor cap.
Step 3, change coolant & thermostat
Step 4, performance mods
 
Gears and tuner will give you the most performance gain for the money..
skip the intake and exhaust, all they'll do is make noise. The cylinder head on that year 4.6 Ford doesn't flow very well...
 
Last edited:
The basic problem is too much vehicle, not enough engine, those should have gotten the 5.3... My '98 Grand Marquis with same 215Hp 4.6 engine is far from a ball of fire...

You could swap heads to the later performance improved type but that's a major outlay of $$$ for minimal return... A higher stall speed converter(that and a tune, probably best bang for the buck) and maybe lower rear gears would help, but won't be cheap...

BTW if the MAF meter is dirty(common issue), performance will suffer...
 
Go through it all and make sure all the maintenance is up to date. They're not power houses, but my dads old truck with the 4.6 was able deal with my 1930 Model A on a trailer without too much trouble. Those engines like to rev a bit, so don't be afraid to take it up to 3k when trying to get going at a decent pace.

I've heard of a few people who feel the CAI did improve pep and improve gas mileage by a bit. I don't have one first hand to confirm, but it seems responsible.
 
Originally Posted By: gfh77665
Just got this 1998 Expedition and I like it, but its a real dog performance wise. The 215 hp 4.6L V8 is anemic. Any tips from you Ford guys out there for a simple, cost effective performance boost? Thank You!


A programmer will be the most cost effective mod you can make. The help with the shifts is enough to win most people over but the power gains are decent also. An SCT device from a place like VMP tuning, Troyer performance, or Power Hungry Performance will be a world of difference.
I don't know what the intake looks like on the Expy, but in the F150 world we do what's called the Gotts mod to the intake to help it breathe easier.
Next on my list would be an electric fan conversion. Did it on my 99' F150 and gained mileage and a little power. If done right they are very reliable and can also be done cheap with Taurus or Mark VII fans.
If you do decide to do the exhaust, short of long tubes, the gains will be minimal. A muffler swap with a straight through muffler will do 75% of what a full cat back will do.
 
Originally Posted By: RamFan
Wait you forgot to mention your mileage and how well it's been maintained!

Step 1, change all fluids.
Step 2, change the spark plugs, plug wires, distributor cap.
Step 3, change coolant & thermostat
Step 4, performance mods


115 K miles, but they have been hard ones. Mother in Law drives two blocks to church and back, etc.

She did really good (too good actually) on oil changes, but did nothing else at all. Engine is tight, does not use any oil, but just anemic. I changed out fuel filter so far...
 
Originally Posted By: stang5
Gears and tuner will give you the most performance gain for the money..
skip the intake and exhaust, all they'll do is make noise. The cylinder head on that year 4.6 Ford doesn't flow very well...


Yeah,forget the CAI and exhaust. Go for a tuning chip.
 
Originally Posted By: NHGUY
5.3? You mean 5.4 Triton.


Yeah no doubt, missed that typo...
 
On a non-PI 4.6L, I think a chip is a waste of time and money. The only thing you *may* improve is shift feel. Though that didn't work out well for another member on here recently with his Crown Vic and a canned tune.

The biggest "issue" with the non-PI engines is that they can't breathe. The cylinder heads are garbage, which is why the PI revision was made in the first place. No amount of chip tuning, CAI or exhaust is going to fix that problem. So you live with it, or you do an upgrade that will actually improve the power output, like a PI 5.4L swap or putting on a set of the Trick-Flow heads. Both are involved and relatively expensive, but going by how much power you are ACTUALLY going to gain doing this over any of the other mods mentioned, the bang per buck may actually be the highest going this route.
 
Originally Posted By: TFB1
The basic problem is too much vehicle, not enough engine, those should have gotten the 5.3... My '98 Grand Marquis with same 215Hp 4.6 engine is far from a ball of fire...

You could swap heads to the later performance improved type but that's a major outlay of $$$ for minimal return... A higher stall speed converter(that and a tune, probably best bang for the buck) and maybe lower rear gears would help, but won't be cheap...

BTW if the MAF meter is dirty(common issue), performance will suffer...



^^^THIS!^^^

Check the MAF. It is rarely serviced, and cleaning it can be an amazingly easy pick me up mod.

My son has had many a 4.6, lets face it, it's a dog stock. Kicking it with more timing via tuning is not going to do much but will make it FEEL better.

I'd consider heads and cam. Nice mod, completely transforms the engine into whatever you pick. Then you need the tuner!
 
tfs-k519-390-375_w.jpg


Originally Posted By: Trickflow
Notes: 390hp/375 ft.-lbs. Aftermarket tuning is required after installation of this kit. Includes 90 lbs. valve springs.


http://www.summitracing.com/parts/TFS-K519-390-375/

Expensive? Yes. But over the 215HP base engine, you are paying $11/HP for this kit and end up with almost twice the power you started off with. You gain 175HP!

In comparison, a canned tuned from SCT will give you a gain of 11HP. You can't even feel that.

http://www.sctflash.com/products.php?PID=2&VID=296

At $380, you are paying $35/HP.
 
i agree the non pi motors are terrible. Dont waste money on tuning, etc. If you truly want to make a bit more power, definitely look into heads and/or cams.
 
Well, thank you all for the replies. Some great information there. I think my "performance mods" will be

1)removing the heavy 3 row seat
2)Run Regane injector cleaner
3)Replace fuel & air filters and
4)Air up tires.
 
Don't bother.

I owned a 220HP 4.6L, 1998 F150. I put headers, exhaust, cold air K+N and a superchips chip on it. The bottom line: Zero real world increase in performance.

I used a G-Tech and was actually able to measure a tiny difference. But, I could not feel it, and my buddies stock truck was exactly matched with my modified truck. So, I spent money and time for nothing.

Don't bother. As mentioned above, the heads are the problem. And, even if you change the heads, you will only pick up high RPM power (over 4500)
 
The 4.6 pushes my little Mustang real good Ha Ha. I'd put some rear gears in it if you want some better pick up. 4.10s should help move you down the road a little quicker.
 
Status
Not open for further replies.
Back
Top