Engine Rev's high, slow to accelerate
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Engine Rev's high, slow to accelerate
My Exp has a 5.4L, tow package and 3.55 axle. I tow a camper weighing 4,600 lbs. Sometimes when starting out from a dead start the engine revs high like an 18 wheeler and accelaerate slowly. As speed picks up the revs quite down. Seems to do it after the trucks been towing a while. Once in a while it does it without the trailer. Is this normal?
Greg
Greg
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From: Northwest
Engine Rev's high, slow to accelerate
No, that isnt normal. Sounds like you need to have your transmission looked at.
Just in case, you arent towing in overdrive at all are you? and you arnt starting out from a dead start in 2nd?
Otherwise it sounds like your tranny is slipping and may need to be looked at closely
Good Luck,
STeve
Just in case, you arent towing in overdrive at all are you? and you arnt starting out from a dead start in 2nd?
Otherwise it sounds like your tranny is slipping and may need to be looked at closely
Good Luck,
STeve
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From: Annapolis, Maryland
Engine Rev's high, slow to accelerate
First off, welcome to FTE! You came to the right place!
I second the opinion that your tranny might be lunching itself. How many miles on the truck, and how many miles since your last tranny flush & fill?
If you're mechanically inclined, I'd suggest pulling the pan and checking for metal shavings. If everything's clean, then fill 'er back up and let us know so we can dig deeper.
Does it do this regardless of whether or not the trailer's present?
Also, towing in OD is a possibility as well - I've had my truck fool itself before (not while towing) and dump it into OD from a dead stop - a scary thing when pulling out into 60MPH traffic!
Try turning the OD off and see if that helps any.
Keep us posted!
XXL
I second the opinion that your tranny might be lunching itself. How many miles on the truck, and how many miles since your last tranny flush & fill?
If you're mechanically inclined, I'd suggest pulling the pan and checking for metal shavings. If everything's clean, then fill 'er back up and let us know so we can dig deeper.
Does it do this regardless of whether or not the trailer's present?
Also, towing in OD is a possibility as well - I've had my truck fool itself before (not while towing) and dump it into OD from a dead stop - a scary thing when pulling out into 60MPH traffic!
Try turning the OD off and see if that helps any.
Keep us posted!
XXL
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Engine Rev's high, slow to accelerate
99% of the time I am not towing in overdrive, only time is on very flat surfaces where I know the transmission is not going to shift alot. Transimission is in the drive position, not 2nd or 1st.
Engine revs like an 18 wheeler does when I start out from a signal light sometimes. If you give it more gas I do pick up speed faster, but the noise gets louder. Transmisson does not appear to be slipping. Then at about 25 mph noise dissapears. I thought it was normal due to the rear axle gear ratio. Current milage is 54,000 and transimission was serviced at 30,000 mph by the ford dealer.
Mostly happens after towing trailer about 50 miles. Does it occasionally without the trailer.
Greg
2000 Expedition, 5.4L, 3.55
Engine revs like an 18 wheeler does when I start out from a signal light sometimes. If you give it more gas I do pick up speed faster, but the noise gets louder. Transmisson does not appear to be slipping. Then at about 25 mph noise dissapears. I thought it was normal due to the rear axle gear ratio. Current milage is 54,000 and transimission was serviced at 30,000 mph by the ford dealer.
Mostly happens after towing trailer about 50 miles. Does it occasionally without the trailer.
Greg
2000 Expedition, 5.4L, 3.55
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From: Annapolis, Maryland
Engine Rev's high, slow to accelerate
Originally posted by Greg230
Mostly happens after towing trailer about 50 miles. Does it occasionally without the trailer.
Mostly happens after towing trailer about 50 miles. Does it occasionally without the trailer.
I'd get it checked out ASAP.
XXL
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From: Burnsville, MN
Engine Rev's high, slow to accelerate
Can you quantify via the tach the rev-up amount, or is it possible that you are hearing a lot of engine noise due to the fan clutch being engaged?
Do a stall test on the transmission and let us know the maximum RPM, that will determine if you have TC issues or slippage in the trans.
Good luck!
Do a stall test on the transmission and let us know the maximum RPM, that will determine if you have TC issues or slippage in the trans.
Good luck!
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Engine Rev's high, slow to accelerate
Have the same thing happen to me once in a while. It seems to me that it only does it if the truck is running hot. I think it's the fan clutch being engaged as the RPM's don't seem to jump. The noise does seem to be loud and there is loss of power. If anyone knows anything more on this matter please advise.
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From: Burnsville, MN
Engine Rev's high, slow to accelerate
That is why I posed the question, my Expedition does it when pulling a trailer up a steep grade at low speed (I have trailer package and heavy duty cooling) and when I have the A/C on while idleing for an extended period and then speed up the engine.
I really hope that this is the basis for Greg's concern. I doubt a tranny issue as the OD light would start flashing in the case of slippage in the transmission and TC failures are normally indicated by a shudder with a potential change in RPM.
Hopefully Greg will get back to us on this...
I really hope that this is the basis for Greg's concern. I doubt a tranny issue as the OD light would start flashing in the case of slippage in the transmission and TC failures are normally indicated by a shudder with a potential change in RPM.
Hopefully Greg will get back to us on this...
Last edited by GR8Diesel; Aug 25, 2003 at 11:19 AM.
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Engine Rev's high, slow to accelerate
Originally posted by GR
iesel
Can you quantify via the tach the rev-up amount, or is it possible that you are hearing a lot of engine noise due to the fan clutch being engaged?
Do a stall test on the transmission and let us know the maximum RPM, that will determine if you have TC issues or slippage in the trans.
Good luck!
iesel Can you quantify via the tach the rev-up amount, or is it possible that you are hearing a lot of engine noise due to the fan clutch being engaged?
Do a stall test on the transmission and let us know the maximum RPM, that will determine if you have TC issues or slippage in the trans.
Good luck!
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Engine Rev's high, slow to accelerate
I'll record alot of info after I do some tow testing this weekend. What is the stall test?
I did see the Ford dealer today after taking my fix or repair daily winstar to them. I described the problem and they said they would like to go for a test drive with the trailer attached.
Greg
I did see the Ford dealer today after taking my fix or repair daily winstar to them. I described the problem and they said they would like to go for a test drive with the trailer attached.
Greg
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From: Burnsville, MN
Engine Rev's high, slow to accelerate
The stall test is a test for transmission slippage and proper torque converter operation. All torque converters have a stall speed which is the maximum input speed with the output shaft being held at zero. This is done by first warming up the transmission, then after applying the parking brake and fully applying the service brakes the transmission in placed into each gear and while the brakes are fully applied moving the throttle to WOT while checking the tachometer reading. Do this for as short of a test as possible as transmission damage due to overheating will occur without warning. Ford recommends no more than 5 seconds of operation, less if the tach reads high as internal slippage is present. For my expedition (99 5.4L w/4r100) the stall speed should be at least 2248 RPM and no more than 2631 RPM.
Again if it is higher than 2631, you have transmission slippage.
If it is under then it is usually an engine performance issue or the torque converter one-way clutch.
When I do a stall test, I try to give at least 30 seconds between each power application to allow the cooler to remove some of the heat.
Good luck and if you do this test please be carefull!
Again if it is higher than 2631, you have transmission slippage.
If it is under then it is usually an engine performance issue or the torque converter one-way clutch.
When I do a stall test, I try to give at least 30 seconds between each power application to allow the cooler to remove some of the heat.
Good luck and if you do this test please be carefull!
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Engine Rev's high, slow to accelerate
I live in Phoenix, and it's normal when the engine gets hot that the engine pushes more air using the fan. Once underway- the fan noise subsides because of the natural air flow from travelling at speed. Most all car's I've had (with engine driven cooling fans) have performed this way- except the foreign jobs I've owned that have electric fans...
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From: fresno ca
Engine Rev's high, slow to accelerate
Its not your tranny, i have the same problem, i live in Fresno CA. and its over 100 degrees everyday, it seems to only do it when it reaches over 100, other than that with the Volant intake and bigger throttle body and exhaust i can burn the tires in the morning. There is a page here in this website that states that you have to redo your PCM (Power Control Module) i havent done it yet but ive heard it should be done under warranty hence its not your fault. (It sucks cause everytime i try to stomp onthe gas it hesitates and makes a pretty loud fan clutch noise) once im moving though its ok. Have your PCM redone $91.00 at the dealer.
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Engine Rev's high, slow to accelerate
I did alot of tests while towing this last weekend. The temp was in the low 90's and it would not make the noise or act like an eighteen wheeler starting out. Only does it when its above 98 degrees. I guess it is normal.
Everyone, thanks for the responses.
Greg
Everyone, thanks for the responses.
Greg