First Road Trip, a Couple of Issues

Marine One · Oct 6, 2006

I drove the new convertible to northern Va today (yes in all the rain). It was a 350 mile trip. We've got two issues. The first was that at the halfway point we got out of the car. My wife was riding in the passenger's seat and pointed out that there was some water on the passenger side floor mat. We had the A/C on for that half of the trip. Initially I couldn't tell if we had an A/C issue or an actual water leak. We switched to defrost for the second half of the trip and saw no more water on the floor mat so I am guessing it was condensation. This shouldn't have happened IMO. Any thoughts?
Second issue/problem is with the speedometer. I've been using my Garmin GPS to check its accuracy. It is off by about 1-2 MPH all the way up to 70 MPH. It reads faster than the car is actually going. What I noticed today is the difference in the reading vs. actual gets worse after 70 MPH. Indicated 80 MPH is only 75 actual MPH. I'm not type A about most things but I am one of those drivers who wants to know exactly what my speed is so that I can know how far I can bend the rules. My car came with the factory 3.55 gears. I'm wondering if there is no speedo / computer correction from the factory for these gears? The speedo is off just enough to be annoying. I'm reluctant to let the dealer touch anything in the dash. The speedo in my 96 Cobra was dead on all the way up. Any thoughts?

anthony05gt · Oct 7, 2006

If you have changed the tires that will affect the speedo even if the tires are minimally different in size. If you have a hand tuner you could enter an inaccurate tire program just for the reason of correcting the speedo. That might bring it closer.

jsawyer · Oct 7, 2006

same water issue

Marine One said:
I drove the new convertible to northern Va today (yes in all the rain). It was a 350 mile trip. We've got two issues. The first was that at the halfway point we got out of the car. My wife was riding in the passenger's seat and pointed out that there was some water on the passenger side floor mat. We had the A/C on for that half of the trip. Initially I couldn't tell if we had an A/C issue or an actual water leak. We switched to defrost for the second half of the trip and saw no more water on the floor mat so I am guessing it was condensation. This shouldn't have happened IMO. Any thoughts?
Second issue/problem is with the speedometer. I've been using my Garmin GPS to check its accuracy. It is off by about 1-2 MPH all the way up to 70 MPH. It reads faster than the car is actually going. What I noticed today is the difference in the reading vs. actual gets worse after 70 MPH. Indicated 80 MPH is only 75 actual MPH. I'm not type A about most things but I am one of those drivers who wants to know exactly what my speed is so that I can know how far I can bend the rules. My car came with the factory 3.55 gears. I'm wondering if there is no speedo / computer correction from the factory for these gears? The speedo is off just enough to be annoying. I'm reluctant to let the dealer touch anything in the dash. The speedo in my 96 Cobra was dead on all the way up. Any thoughts?

Right after I bought my car I washed it on a steep hill. When I pulled the car back into my driveway I noticed a stream of water running onto the passenger side floor mat? I think that the drain from behind the cowel has an issue that is yet to be discovered. It has not happened since

bigcat · Oct 7, 2006

use another cars speedo, driving next to you at the same speed, or ask a cop to radar you when going a set speed. then there are always those radar signs that says SPPED LIMIT XX YOUR SPEED XX. compared to one of those, my car is accurate.

tr7driver · Oct 7, 2006

A quick and ez check; drive 60 mph on a highway with posted mile markers. It should take you one minute to go from one mile marker to the next. Try 5 miles for a better reading.

Marine One · Oct 8, 2006

I am pretty sure that the water was A/C condensation as once we shut the air off it was fine, and we drove through some really heavy rain afterward.

I reflashed my computer with my SCT-2, & changed the axle ratio to 3.73, and now according to my GPS the speedo is spot on. Tires & wheels are the stock 17s. Am I correct in assuming the axle ratio setting does nothing other than recalibrate the speedo?

hollant · Oct 8, 2006

WOW, two whole miles per hour off at 70mph! Thats almost three percent. I'd take the car back! (I love marines! )

Mike97gt · Oct 8, 2006

for the water issue you may have somthing blocking the drain for the a/c evap core. if you look at the firewall under the hood with the car up in the air you should see the drain almost directly under where the a/c lines enter the cabin. B low that out with compressed air.

Another thing that can cause this and is common on many fords is a water leak coming from the passenger side cowl seal, this is easily solved by removing the cowl cover on the passenger side and running a line of RTV under it and reinstalling the cowl.

As far as the speedo is concerned we will not attempt a repair on that, it's considered normal on any car for the speedo to be off a few mph at highway speeds.

351CJ · Oct 9, 2006

A few years ago C&D tested the speedos on ~20 cars from different manufacturers. EVERY one of them read high (car going slower than speedo indicates). All the Fords they tested were pretty consistant @ 2 MPH high. Most GMs were 3 - 4 high and most imports were 3 - 5 high. They checked with some manufacturers but did not get any official comments. Unofficially it was indicated that the speedos intentionaly read high so nobody can sue them for getting a speeding ticket.

I've had a number of Fords and almost all of them had speedos that read about 2 MPH high.

Also, according to C&D all the odometers were pretty accurate, more accurate than the speedos.

Marine One · Oct 9, 2006

svttech76 said:
for the water issue you may have somthing blocking the drain for the a/c evap core. if you look at the firewall under the hood with the car up in the air you should see the drain almost directly under where the a/c lines enter the cabin. B low that out with compressed air.

Another thing that can cause this and is common on many fords is a water leak coming from the passenger side cowl seal, this is easily solved by removing the cowl cover on the passenger side and running a line of RTV under it and reinstalling the cowl.

As far as the speedo is concerned we will not attempt a repair on that, it's considered normal on any car for the speedo to be off a few mph at highway speeds.

Thanks for the advice. Ran all the way back to NC today w/the A/C on and no moisture. I'm leaning toward thinking it's a cowl leak. Question now is should I have the dealer fix it under warranty, or do it myself?

The speedo is off by 5-7 MPH at speeds above 70. The faster I go the worse it gets. If I reflash with my SCT-2 and change the input for the axle ratio from stock to 3.73the speedo is almost dead on no matter the speed, but I'm guessing it will throw the odometer off? I guess getting the dealer to reflash the computer for speedometer error isn't an option??

Marine One · Oct 9, 2006

hollant said:
WOW, two whole miles per hour off at 70mph! Thats almost three percent. I'd take the car back! (I love marines! )

Hey, what can I say??

Mike97gt · Oct 10, 2006

Marine One said:
Thanks for the advice. Ran all the way back to NC today w/the A/C on and no moisture. I'm leaning toward thinking it's a cowl leak. Question now is should I have the dealer fix it under warranty, or do it myself?

The speedo is off by 5-7 MPH at speeds above 70. The faster I go the worse it gets. If I reflash with my SCT-2 and change the input for the axle ratio from stock to 3.73the speedo is almost dead on no matter the speed, but I'm guessing it will throw the odometer off? I guess getting the dealer to reflash the computer for speedometer error isn't an option??

7+ mph at 70 is a problem I would ask for a reflash for that. hopefully that will help if not they would have to look further into it to try and figure out what is messing with the signal or if the cluster itself is the problem.

For the water leak I would bring it to them, if they are too stupid to figure it out then you can try and do it yourself, it's easy all you do is lay a bead of clear silicone along the base of the windsheild under the cowl cover.

hedgehogrgc · Oct 10, 2006

My window leaks periodically on the passenger side, I bring it in to the dealer and he says " i could not reproduce it" one or 2 drops on the seat occasionally. It stumped me also..I just hope it doesnt propogate into a bigger problem.

Marine One · Oct 10, 2006

svttech76 said:
7+ mph at 70 is a problem I would ask for a reflash for that. hopefully that will help if not they would have to look further into it to try and figure out what is messing with the signal or if the cluster itself is the problem.

For the water leak I would bring it to them, if they are too stupid to figure it out then you can try and do it yourself, it's easy all you do is lay a bead of clear silicone along the base of the windsheild under the cowl cover.

The last thing that I want is the service dept monkeying around with a dash cluster that otherwise works fine and doesn't make a sound. If they can reflash it or replace a sensor somewhere to fix this, that would be the best answer. My thought is to tell them about the problem, then see what they plan to do about it. I' probably go as far as to tell them that I don't want them tearing into my dash.

Is the cowl cover held into place by fasteners or does it just snap into place? Based on hedghogrgc's post I don't have much confidence that they'll be able to fix it, especially if they have to duplicate the problem first.

hedgehogrgc · Oct 10, 2006

I have had that happen a couple of times the dealer not being able to reproduce it for example the whine in the rear end and the sluggishness on accelleration after cruising on the the highway. But thank to this site and the tsb's that were provided I sort of pushed the dealership into fixing the problems....hence the reason for sitting here online as opposed to out enjoying my car before i leave for tour to afghanistan.

Marine One · Oct 10, 2006

hedgehogrgc said:
I have had that happen a couple of times the dealer not being able to reproduce it for example the whine in the rear end and the sluggishness on accelleration after cruising on the the highway. But thank to this site and the tsb's that were provided I sort of pushed the dealership into fixing the problems....hence the reason for sitting here online as opposed to out enjoying my car before i leave for tour to afghanistan.

How long are you going over for?

hedgehogrgc · Oct 10, 2006

I am going over for who knows....maybe as late as june of next year. This is due to the lack of armoured engineers. And I can't wait to get back this time we have the punch needed with the tanks.

Marine One · Oct 10, 2006

hedgehogrgc said:
I am going over for who knows....maybe as late as june of next year. This is due to the lack of armoured engineers. And I can't wait to get back this time we have the punch needed with the tanks.

I never made it to Afghanistan but have done two tours in Iraq. Be careful over there!

projp · Oct 10, 2006

My 07 with 3.55's reads 3 mph fast at 70 also.

hedgehogrgc · Oct 10, 2006

thanks i have 48 tons of armour around me this time ( last time i was on foot)....and its good to see you made it out of that other s***hole alive...Twice!
And it happened again....the dealer couldnt re produce the problem. i couldnt either...lol

First Road Trip, a Couple of Issues

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