Would someone please help me to improve the performance on my 1998 4.6L F150 with 5 speed manual transmission.
I bought this trunk not too long ago from a mom & pop car dealer. When I bought the truck, I could not take it to the freeway speed to check it (it was during the rush hour.) After buying, I became more frustrated with its performance as the day goes by. It was a very difficult task for me to keep up with the little Geo Metro in the next lane. In order for me to keep up with
everyone else at the traffic light, I must operate the truck in the 3000-3500 rpm range. Going uphill requires the third gear in the 3000 rpm. I do not think this is normal.
On the freeway, I have basically no passing power in the fourth and fifth gear. The gas mileage I am getting (when I keep the engine operating at around 2000-2500) is around 16.5 mile per gallon. The truck does not seems to be losing oil. However, at times, the engine sounds like it backs fire (it sounds like an old car with a leaky exhaust).
Other thing that I notice that when I park the truck in a driveway with an incline of about 20 degree, the truck would roll back. When I park the vehicle, I normally do not use the brake; I normally would put the truck in either first gear or the reverse. When it rolls back, it would roll some and then stop and then roll again. I have never seen this happens with other truck that I have driven before. Does it mean the engine compression is bad or the transmission clutch is bad? According to the guy at the dealer who sold me the truck, the clutch was replaced when the slave cylinder in the transmission was replaced. Another thing that I noticed is that sometimes when I put the truck into first gear, it was shaking a little bit.
What can I do to check? I hate to take the truck to Ford and waste my money.
How can I check the engine compression?
and how can I check to see if the clutch is still good?
Thanks,
I bought this trunk not too long ago from a mom & pop car dealer. When I bought the truck, I could not take it to the freeway speed to check it (it was during the rush hour.) After buying, I became more frustrated with its performance as the day goes by. It was a very difficult task for me to keep up with the little Geo Metro in the next lane. In order for me to keep up with
everyone else at the traffic light, I must operate the truck in the 3000-3500 rpm range. Going uphill requires the third gear in the 3000 rpm. I do not think this is normal.
On the freeway, I have basically no passing power in the fourth and fifth gear. The gas mileage I am getting (when I keep the engine operating at around 2000-2500) is around 16.5 mile per gallon. The truck does not seems to be losing oil. However, at times, the engine sounds like it backs fire (it sounds like an old car with a leaky exhaust).
Other thing that I notice that when I park the truck in a driveway with an incline of about 20 degree, the truck would roll back. When I park the vehicle, I normally do not use the brake; I normally would put the truck in either first gear or the reverse. When it rolls back, it would roll some and then stop and then roll again. I have never seen this happens with other truck that I have driven before. Does it mean the engine compression is bad or the transmission clutch is bad? According to the guy at the dealer who sold me the truck, the clutch was replaced when the slave cylinder in the transmission was replaced. Another thing that I noticed is that sometimes when I put the truck into first gear, it was shaking a little bit.
What can I do to check? I hate to take the truck to Ford and waste my money.
How can I check the engine compression?
and how can I check to see if the clutch is still good?
Thanks,
If your truck rolls back when it is in 1st gear is a sign of very low engine compression or a slipping clutch. How many miles on the truck? Over 50,000??
Check the clutch by driving in 5tgh gear at 40 mph and florring it. It should not rev up at all. If it does check the tach and speed and let me know what it was. If the clutch is ok get a compression check done.
If that checks out Start by changing the plugs, the front O2 sensors, fuel filter, air filter and clean the MAF sensor wires. This should perk the critter right up.
BTY do not expect passing power in 4th gear the 4.6 just doesn't have it.
Regards
Jean Marc Chartier
EDIT: one more thing I just thought of; What gears do you have? Check the Axle code on the Vehicle cert card on the drived door pillar.
Check the clutch by driving in 5tgh gear at 40 mph and florring it. It should not rev up at all. If it does check the tach and speed and let me know what it was. If the clutch is ok get a compression check done.
If that checks out Start by changing the plugs, the front O2 sensors, fuel filter, air filter and clean the MAF sensor wires. This should perk the critter right up.
BTY do not expect passing power in 4th gear the 4.6 just doesn't have it.
Regards
Jean Marc Chartier
EDIT: one more thing I just thought of; What gears do you have? Check the Axle code on the Vehicle cert card on the drived door pillar.
Hello JMC,
Thank you very much for the response.
The truck has 122,000 miles on it. I have no idea what type of gear I have; but on the door pillar, it has a code of "H9". Do you know what this code mean?
BTW, I have replaced the fuel filter, the spark plugs and the cable as well. I did not replace the air filter yet since it still look clean to me.
I just took the truck out for a spin after putting some "sea foam", I did not notice any diffrence. When I was travelling at 40 mph, the tach shows roughly 1500 RPM. When I floored it, the truck did not rev up at all. The speed increases a little bit, though.
From what I have seen so far, it looks like I may have a low compression. What are the possible causes for it beside the worn out rings? Is there such thing as "valve adjustment"? I am praying for something other than engine replacement or rebuilt.
Thank you very much for the response.
The truck has 122,000 miles on it. I have no idea what type of gear I have; but on the door pillar, it has a code of "H9". Do you know what this code mean?
BTW, I have replaced the fuel filter, the spark plugs and the cable as well. I did not replace the air filter yet since it still look clean to me.
I just took the truck out for a spin after putting some "sea foam", I did not notice any diffrence. When I was travelling at 40 mph, the tach shows roughly 1500 RPM. When I floored it, the truck did not rev up at all. The speed increases a little bit, though.
From what I have seen so far, it looks like I may have a low compression. What are the possible causes for it beside the worn out rings? Is there such thing as "valve adjustment"? I am praying for something other than engine replacement or rebuilt.
Hello JMC
I was hitting the wrong key and the next thing I know the response was submitted before I finished.
Do you have any instruction on how to clean the MAF sensor wire?
and do you know what is the typical engine compression pressure for this type of engine? If I have this information, may be I do the compression check by myself.
Thank again.
I was hitting the wrong key and the next thing I know the response was submitted before I finished.
Do you have any instruction on how to clean the MAF sensor wire?
and do you know what is the typical engine compression pressure for this type of engine? If I have this information, may be I do the compression check by myself.
Thank again.
To clean thye MAf sensor wires I use windex on a Q-tip. Gently strioke the wires with the Q-tip. Wipe it with a dry Q-tip.
to get to the MAF wires remove the Air Filter and lift the Air inlet and you will see the MAF ensor sticking up into the tube.
For testing compression the chart shows a a start of 134 psi and it go up in 2 psi increments to a max of 250. The lowest reading should be 75% of the higest reading. So if you have a high of 150 psi the lowest cylinder should be no lower than 75% of 150 or 112.5 psi. Remove all the plugs and check the compression with the throttle plate all the way open and turn it a minimum of 5 compression strokes.
JMC
to get to the MAF wires remove the Air Filter and lift the Air inlet and you will see the MAF ensor sticking up into the tube.
For testing compression the chart shows a a start of 134 psi and it go up in 2 psi increments to a max of 250. The lowest reading should be 75% of the higest reading. So if you have a high of 150 psi the lowest cylinder should be no lower than 75% of 150 or 112.5 psi. Remove all the plugs and check the compression with the throttle plate all the way open and turn it a minimum of 5 compression strokes.
JMC
Senior Member
GrandmaF150,
I have a very similar problem with my '98 F150 SuperCab 4.6 5-speed. I bought it with 60k on it 2.5 years ago. It now has 95k. It has never shown any engine fault, and I just recently let Ford check it out again to tell me what exactly made my truck so doggy. Well, they checked it top to bottom and said there was absolutely nothing wrong with it. The sales manager even offered to take me for a drive, him driving, to prove it to me. I don't know why, but when I'm in the passenger seat and someone else is driving, they can make it feel like a hot rod and I just look stupid. But they can't fix what ain't broke. I just did my first plug change at 95k (another adventure), and it 'seemed' to pick it up somewhat. Just made a fairly long trip this weekend with the new plugs and it made a drastic improvement in the mileage. On a 75+% highway ride over 400 miles, I averaged 18.9 mpg! I have the same feeling you have sometimes; I shouldn't have to make it scream like a Nascar stocker to keep up with every granny's old Buick. You know as loud as it sounds to you in the cab, it has to be blowing everybody outside away. I had the identical truck prior to this one, only it was an auto, and it felt like it had twice the motor (still a 4.6). Both are geared with 3.55's (same as yours by the way, an H9, and both 2WD with same diameter wheels/tires). Why would the stick 4.6 have to rev so much more than an auto 4.6 to achieve the same acceleration? BUT, once in motion and at a good highway speed, my truck seems to change personalities. I don't do many 'holy cow' passes, but I can usually make a good pass and never take it out of 5th. It'll pull like a train up a pretty long grade in 5th without having to shift down (by the way, I thought that mashing the clutch while in cruise would disengage the cruise, but on my truck it doesn't; I thought I'd give her some help up a particularly long hill and had the cruise on and stepped on the clutch pedal to make a downshift, thinking the cruise would shut off; it didn't, and man, did she scream!; I was afraid something was going to give before I could get the cruise off). I know this 5-speed truck was never meant to be a speed demon, but what's the fun of choosing a stick over an auto if you can't make the stick do a little more? I'm glad I'm not the only one who has this feeling. Maybe they all run like this, but this is the only 5-speed 4.6 I've ever driven, so I have nothing to compare it to. Before buying my first '97 SuperCab auto truck, I had a '95 Silverado extended cab (please forgive me, don't know what I was thinking), with a 200HP non-Vortec 350 and a 5-speed, and a 3.08 rear. It kinda had the same feeling, BUT at will I could pat the pedal in 1st at just about any speed and break the rear loose. I don't think my 4.6 could do that on wet pavement. Or maybe I'm just a little older and don't try that kind of stuff anymore (???). Anyway, if you get any revelations, please let me know. I love my truck to death and don't plan on getting rid of it anytime soon; I'd sure like to know if it's really running up to the level it was meant to, though. Later!
I have a very similar problem with my '98 F150 SuperCab 4.6 5-speed. I bought it with 60k on it 2.5 years ago. It now has 95k. It has never shown any engine fault, and I just recently let Ford check it out again to tell me what exactly made my truck so doggy. Well, they checked it top to bottom and said there was absolutely nothing wrong with it. The sales manager even offered to take me for a drive, him driving, to prove it to me. I don't know why, but when I'm in the passenger seat and someone else is driving, they can make it feel like a hot rod and I just look stupid. But they can't fix what ain't broke. I just did my first plug change at 95k (another adventure), and it 'seemed' to pick it up somewhat. Just made a fairly long trip this weekend with the new plugs and it made a drastic improvement in the mileage. On a 75+% highway ride over 400 miles, I averaged 18.9 mpg! I have the same feeling you have sometimes; I shouldn't have to make it scream like a Nascar stocker to keep up with every granny's old Buick. You know as loud as it sounds to you in the cab, it has to be blowing everybody outside away. I had the identical truck prior to this one, only it was an auto, and it felt like it had twice the motor (still a 4.6). Both are geared with 3.55's (same as yours by the way, an H9, and both 2WD with same diameter wheels/tires). Why would the stick 4.6 have to rev so much more than an auto 4.6 to achieve the same acceleration? BUT, once in motion and at a good highway speed, my truck seems to change personalities. I don't do many 'holy cow' passes, but I can usually make a good pass and never take it out of 5th. It'll pull like a train up a pretty long grade in 5th without having to shift down (by the way, I thought that mashing the clutch while in cruise would disengage the cruise, but on my truck it doesn't; I thought I'd give her some help up a particularly long hill and had the cruise on and stepped on the clutch pedal to make a downshift, thinking the cruise would shut off; it didn't, and man, did she scream!; I was afraid something was going to give before I could get the cruise off). I know this 5-speed truck was never meant to be a speed demon, but what's the fun of choosing a stick over an auto if you can't make the stick do a little more? I'm glad I'm not the only one who has this feeling. Maybe they all run like this, but this is the only 5-speed 4.6 I've ever driven, so I have nothing to compare it to. Before buying my first '97 SuperCab auto truck, I had a '95 Silverado extended cab (please forgive me, don't know what I was thinking), with a 200HP non-Vortec 350 and a 5-speed, and a 3.08 rear. It kinda had the same feeling, BUT at will I could pat the pedal in 1st at just about any speed and break the rear loose. I don't think my 4.6 could do that on wet pavement. Or maybe I'm just a little older and don't try that kind of stuff anymore (???). Anyway, if you get any revelations, please let me know. I love my truck to death and don't plan on getting rid of it anytime soon; I'd sure like to know if it's really running up to the level it was meant to, though. Later!
Senior Member
i have a 97 flareside reg cab with the 4.6 5 speed and i will agree it is not a race car for sure but i can break loose the tire all the way thru 3 rd gear with little effort. My truck is stock and still on oem plugs,wire,etc... It (the 5 speed) is not the best tranny and speed shifting is out of the question. I have some days when it wants to go like hell and some where it is a little sluggish (humid days). I am happy with it and maybe a chip, exhaust change,air filter setup may help you. I have 3.08 gears that make it even worse but it can and does keep up with just about anyone out there getting out of 5th is key. Remember an auto changes gears when more power is given so you need to do the same.
edit: remember to set the brake when on any kind of hill, if its steep enough your truck will roll.....
edit: remember to set the brake when on any kind of hill, if its steep enough your truck will roll.....
Fordman3 wrote:
I know this 5-speed truck was never meant to be a speed demon,
but what's the fun of choosing a stick over an auto if you can't
make the stick do a little more? I'm glad I'm not the only one
who has this feeling. Maybe they all run like this, but this is the
only 5-speed 4.6 I've ever driven, so I have nothing to compare it to.
Fordman3,
You are right. When I bought the truck with stick shift, I was thinking that I would have a good time with it. Occasionally, I would borrow my father-in-law 82 F150 4 speed manual tranmission before and the thing was hauling ***. This is the reason why I was disappointed with the performance on my truck. I also drove the E-350 and the Chevy Silverado with a 350 before. I was used to having the reserve power in the engine to break away from the potential problem. Now having this truck, it is like driving a bus. Especially, when the traffic light turns yellow and someone is tailing behind, it is very disappointing when I step on the gas and still do not have the power to clear the intersection quick enough.
buckdropper wrote:
I have some days when it wants to go
like hell and some where it is a little sluggish (humid days). I am happy with it and maybe a chip, exhaust change,air filter setup may help you. I have 3.08 gears that make it even worse but it can and does keep up with just about anyone out there getting out of 5th is key. Remember an auto changes gears when more power is given so you need to do the same.
Buckdropper,
I think I am going to have the engine compression check first and then I may think about a chip or exhaust change. However do you have any recommendation for the chip and the exhaust set up?
Thanks,
I know this 5-speed truck was never meant to be a speed demon,
but what's the fun of choosing a stick over an auto if you can't
make the stick do a little more? I'm glad I'm not the only one
who has this feeling. Maybe they all run like this, but this is the
only 5-speed 4.6 I've ever driven, so I have nothing to compare it to.
Fordman3,
You are right. When I bought the truck with stick shift, I was thinking that I would have a good time with it. Occasionally, I would borrow my father-in-law 82 F150 4 speed manual tranmission before and the thing was hauling ***. This is the reason why I was disappointed with the performance on my truck. I also drove the E-350 and the Chevy Silverado with a 350 before. I was used to having the reserve power in the engine to break away from the potential problem. Now having this truck, it is like driving a bus. Especially, when the traffic light turns yellow and someone is tailing behind, it is very disappointing when I step on the gas and still do not have the power to clear the intersection quick enough.
buckdropper wrote:
I have some days when it wants to go
like hell and some where it is a little sluggish (humid days). I am happy with it and maybe a chip, exhaust change,air filter setup may help you. I have 3.08 gears that make it even worse but it can and does keep up with just about anyone out there getting out of 5th is key. Remember an auto changes gears when more power is given so you need to do the same.
Buckdropper,
I think I am going to have the engine compression check first and then I may think about a chip or exhaust change. However do you have any recommendation for the chip and the exhaust set up?
Thanks,
Senior Member
Have you checked your exhaust system? You might have a bit of fouling on the cats which would seriously reduce enginer power.
Grim
Grim
Member
When I got my 4.6 5 speed truck the first thing I noticed is how low the first 3 gears are compared to the tremec in my mustang. These 5 speeds are geared for pulling and hauling weight so you are going to be revving way higher to go the same speed as the passenger car next to you at the light and your going to notice it more than you would with an automatic that shifts itself. The gearing in these 5 speeds took me some time to get used to cause they really aren't geared for street driving which is why im gonna replace it with a Tremec when it goes. That being said my truck isnt as slow as you describe, I have plenty of power for passing gear in 4th and I can pretty much melt my tires in 1st and 2nd gears (not something I do all the time by any means). The torque is enough to make it fun to drive and I have a 375HP mustang to compare it to. It could also help that my truck is one of the lighter f-150's (no frills reg cab, shortbed 2wd). I would suggest the magnaflow catback and the Super Chips Max Micro tuner. You can get all this stuff from Troyer also talk to Mike, he'll tell ya anything you need to know about performance upgrades for your truck!
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