help with 2006 Ford Mustang gt stopping

[andrew riesinger]

My Mustang is having a weird issue that most mechanics cannot seem to figure out since no lights show up

Pretty much when I go downhill or turn while going uphill, the car will "Stop" on very random select times

For example ill be going 65 on freeway about to change to a different freeway. That freeway has an on ramp that goes upwards. Ill start turning and press the gas and the car will stop accelerating, will make a very loud revving sound and will start shaking. Ill let go of gas and slowly press gas pedal and everything is fine again.

This even happened while leaving a shopping center the other day. Had the car parked for an hour. Drove about 35, turned left on a flat road and it happened again.

The shaking is similar to how your car shakes when you get a flat tire. 2006 Ford Mustang GT. Great great condition garage kept. Never any issues ever besides this and the door panels coming off. Automatic

Ty

 

[stkjock]

Your title is very misleading.

sounds like a transmission slipping to me.

 

[Lime1Gt]

You might want to check if the fuel pump has been changed before as per TSB06-09-09.

https://latemodel.cachefly.net/downloads/tsb05-14/tsb06-09-09.pdf

 

[datmbn]

Slipping gearbox
check the oil level in the gearbox
if there is too little oil in the gearbox, the pump can suck air when turning or braking/accelerating or driving on a slope.

 

[andrew riesinger]

To reply to all you, it sounds like my best course of action is replacing the fuel pump, and replacing the transmission fluid correct?

 

[Dino Dino Bambino]

Slipping gearbox
check the oil level in the gearbox
if there is too little oil in the gearbox, the pump can suck air when turning or braking/accelerating or driving on a slope.

I was also thinking slipping transmission and since the 5R55S doesn't have a dipstick (great idea Ford!), it's possible the fluid level is low.
I suggest you have the tranny fluid/filter replaced and see how it goes. DO NOT, and I repeat DO NOT, allow any shop to flush the transmission!

 

[Pentalab]

I was also thinking slipping transmission and since the 5R55S doesn't have a dipstick (great idea Ford!), it's possible the fluid level is low.
I suggest you have the tranny fluid/filter replaced and see how it goes. DO NOT, and I repeat DO NOT, allow any shop to flush the transmission!

If the ATF in the 5r55s hasn't been changed out since 2006, and is low on level, it should be emptied, including the converter. A combo of vac + pressure gets it all out. The oem setup, without the dipstick, was a stupid idea. I replaced mine with the PA deeper aluminum pan, holds an extra 4 qts. The PA deeper pan comes with a locking style dipstick, which ends up on the firewall next to the battery. Dipstick opening is big enough to easily add more ATF.

Drain plug on bottom of new pan. Also installed the JDM engineering catch can for the 5R55S. Without it, ATF finds a round about way to puke all over the ground, when heated. Also installed a 2nd ( bar + plate type, made by B+M) auto tranny cooler, plumbed in series with the OEM unit. Also used 100% synthetic ATF. End of problems.

 

[Laga]

Not only does the elimination of the dip stick prevent contamination by water and dirt. It eliminates the number one cause of AT failures. Owners having under/over filled units, or using the wrong fluid. Manufacturers got tired of fighting warranty claims from people screwing up their transmissions.

 

[Midlife Crises]

You are describing an automatic transmission slipping. Transmission is failing or low on fluid. Have the fluid level checked before you kill the transmission. Next would be to do as Pentalab suggests and add the pan and dipstick.

 

[Pentalab]

Not only does the elimination of the dip stick prevent contamination by water and dirt. It eliminates the number one cause of AT failures. Owners having under/over filled units, or using the wrong fluid. Manufacturers got tired of fighting warranty claims from people screwing up their transmissions.

On that Performance automatic deeper pan, with the hd locking dipstick, there is no way in hell you can get water or dirt in there. Without the catch can, ATF will puke all over the ground. You could be down a bunch on ATF fluid, and never know..... until it's too late, and it starts slipping..and overheating. Before I added the 2nd tranny cooler, my ATF temps would rise from 170 F to 200 F, in just 5-7 seconds on the highway with the small Roush M90 blower on. With the 2nd cooler installed, ATF temps rise to just 171 F..and sometime 172 F. I added the 2nd cooler..dead last, it was the last piece of the puzzle. Normal temp on the hwy, cruising is 170 F.

 

[Midlife Crises]

I have always believed engine and transmission oils should run 200 to 220F to “steam” off water vapor and fuel contamination. Oil temperatures below that do not need a cooler.

 

[Dino Dino Bambino]

Not only does the elimination of the dip stick prevent contamination by water and dirt. It eliminates the number one cause of AT failures. Owners having under/over filled units, or using the wrong fluid. Manufacturers got tired of fighting warranty claims from people screwing up their transmissions.

I've never ever heard of dirt or water getting in through the dipstick tube, and the no.1 cause of AT failures is too much heat. Most people drive their automatics in stop/go traffic and spend a lot of time stopped with their foot on the brake and the gear selector in D. This leaves the torque converter spinning and generating a lot of heat. Couple that with longer manufacturer recommended intervals between fluid changes or even "sealed for life" transmissions, and the result is built in obsolescence.
The optimum AT fluid temperature is around 175-220*F and Pentalab has already described the second best way to prolong AT life (auxiliary cooler). The best way of all is to put your tranny selector in P or N when you're stuck in non-moving traffic to keep the torque converter from spinning.

 

[Pentalab]

I have always believed engine and transmission oils should run 200 to 220F to “steam” off water vapor and fuel contamination. Oil temperatures below that do not need a cooler.

The story I got from 1/2 dozen auto tranny experts all said anything < 200 F is ok. 200F is marginal. Anything > 200F is bad news. > 220 F you will destroy it asap. With normal driving, around town, it takes quite a while to get to 155F..( with 2nd cooler installed). Once on the hwy, it quickly ramps up to exactly 170 F..and stays put...... until I mash the gas, drop down a gear, and blower on, then it ramps up to 200F . So in went the extra cooler. Now it never exceeds 171-172 tops. Jay ( who got booted) road raced his 2010 GT auto + same blower.... and the poor 5R55S would get so hot, that it would shift itself into OD. That's a built in safety feature on the 5R55S. With OD off, get it too hot, and it will override, and shift into OD (5th)...to reduce eng rpm..trying to save itself. Jay ended up modifying the bumper, and installed an even bigger B+M cooler than I have..( 20 k btu vs 13 k btu). Even with that mod, it was only good for 1-2 track sessions, then it would start shifting itself into OD.

Engine oil, if dino oil used is bad news if road racing. Once it hits 250 F, it's done, done, finished. 100% synthetic is good for 300F or a bit more. The 11+ cars will easily hit 300-320F while road racing.... hence the oil cooler install. And that's on cars with no blower. Put an oil temp gauge on the eng, and you will be in for a rude awakening.

I can read the 5R55S tranny temps via my aeroforce gauges plugged into OBD port. That was a rude awakening. I would really be concerned if using any auto tranny in say a truck, and towing anything up hills in the summer time. IMO, the 5R55S is marginal at best, it's barely adequate. Without the catch can, it pukes ATF all over the ground, you lose ATF, and then problems just compound. Without a dipstick, you have absolutely no clue what the hell is going on.

 

[Midlife Crises]

250 F, it's done,

Completely agree that 250F will kill Dino oil in a flash. That oil is done. Increasing fluid capacity along with better/more coolers will go a long way to control fluid temperature. Thermal valves can also be used to maintain constant fluid temperatures under variable loads if the problem is persistent.
I maintain my wife’s Thunderbird with that ridiculous, almost sealed 5R55 transmission. Stupid doesn’t begin to describe the trani fluid level check procedure.

 

[Midlife Crises]

The best way of all is to put your tranny selector in P or N when you're stuck in non-moving traffic to keep the torque converter from spinning.

I thought the torque converter was bolted to the flywheel.

 

[Lime1Gt]

To reply to all you, it sounds like my best course of action is replacing the fuel pump, and replacing the transmission fluid correct?

If you have the symptoms that are described in the tsb then yes, the fuel pump should be considered.

The transmission has no dipstick as mentioned before. This is to prevent the wrong fluid being used which may change the co-efficient of friction designed for that transmissions clutches and shift quality. If the transmission, cooler or lines show no signs of leakage the fluid should be at proper level. So check under the car for red color leaks. Also have the vehicle checked for codes related to transmission and engine issues. Do a search on the internet for 5R55S issues and see if any of them relate to your symptoms. The very limited research I've done on the 5R5S5 has been servo bores wear and may cause issues as the trans fluid heats, thins out and leaks past the servo bore pins. You may get codes if this happens. FordTechMakuloco has some videos on the 5R5S5.

 

[07 Boss]

I thought the torque converter was bolted to the flywheel.

It is but what he meant was the TC spinning against itself. That's what builds up heat. If the convertor is locked up less heat is produced. It's when the convertor is "slipping" or spinning is when heat is produced at a much higher rate.