V8 4.4i Weird Tranmission Problem - Failsafe and Noise

thetechguy · #1 10-21-2012, 07:29 PM

I have read lots of other transmission problems on the forum but think mine is a bit different.

I have a 2002 E53 Auto 4.4i X5.

I was driving through the city when all of a sudden the failsafe came on and I only have 3rd or 4th gear.

Tacho + Speedo died, ABS + DSC lights came on.

Got home, left the car and tried to restart 4 hours later and works fine.

When the transmission is cold I can drive for 3 - 5 mins maybe, but as soon as it warms up the failsafe kicks in and if I put the transmission in drive or reverse while holding the brake it make a loud whining noise, similar to a power steering pump.

I have never had any slip, the car did have a slight kick in down gearing from 2nd to 1st.

I did scan the car with a launch scanner and got terminal 30 error, and CAN messages.

I am thinking that maybe the oil is full of crap and putting strain on the transmission's pump and that could be causing the failsafe.

A mechanic friend of mine suggested the clutches could be worn and the debris is in the oil and blocking the pump but if they were worn wouldn't the transmission slip?

SlickGT1 · #2 10-21-2012, 08:08 PM

You sure it's not the alternator giving you over voltage. Search alternator and transmission for similar issues. Monitor your voltage first. Link in my sig will show you how to do that. Report back voltage you get.

thetechguy · #3 10-21-2012, 08:15 PM

Hi Slick,

Thanks for the reply, I have tested battery and alternator, I have the load tester and battery is excellent and alternator is showing 14.6V from memory while running.

I initially did think it was electrical but after hearing the noise coming from the transmission I was sure it had to be mechanical.

SlickGT1 · #4 10-21-2012, 09:41 PM

Quote:

Originally Posted by thetechguy

Hi Slick,

Thanks for the reply, I have tested battery and alternator, I have the load tester and battery is excellent and alternator is showing 14.6V from memory while running.

I initially did think it was electrical but after hearing the noise coming from the transmission I was sure it had to be mechanical.

Yea I realized the noise part, but wasn't yet ready to say the TC was toast. Trix5 is right about a dead TC toasting your trans. My logic is that you manage to drive before you get the error. Then your entire cluster fails. Then the fact that 14.6v is way, way too high. Alternator producing over voltage like that can make everything sound and act strange.

TriX5 · #5 10-21-2012, 09:03 PM

Most likely your torq converter is toast and the gear box is full of trash coming from the TC. There is a bearing in the TC, when it breaks it spits shavings int the fluid stream which get stuck in the valve body. At that point the VB stops working as designed and most likely blows a couple of o-rings.

Mine was making a grinding/whining noise and I took it out, refurbed it. Now have 12,000 miles on it and still working.

Good luck on the fix.

thetechguy · #6 10-21-2012, 11:31 PM

Thanks guys,

TriX5,
My trans doesn't grind it make a noise like fluid rushing very fast but certainly no grinding, is this the same noise your herd?

SlickGT1,
I will double check the voltage tonight, what should it be at idle?

SlickGT1 · #7 10-21-2012, 11:59 PM

Idle under load, like lights and stereo, you should stay between 13-14.1 max. I am more curious of your voltage while driving, right when the trans failsafe and cluster failure happen.

thetechguy · #8 10-22-2012, 01:48 AM

Also does anyone know if the ZF 5HP24 transmission from a Land Rover Discovery will suit an X5?

RRPhil · #9 10-25-2012, 06:19 AM

Quote:

Originally Posted by thetechguy

Also does anyone know if the ZF 5HP24 transmission from a Land Rover Discovery will suit an X5?

The Disco was never fitted with the 5HP24.

It may be worth pointing out that there are 27 variants of the 5HP24 transmission which use five different transmission maincases. A Jaguar or BMW 5HP24 car transmission cannot be made to fit the E53 because the back end of the casing is designed to accommodate attachment to the transfer box. Similarly the Range Rover casing is different to the E53’s because the transfer boxes are different (single range NV125 vs two range NV225). The ‘034’ model of the 5HP24 used in the 4.6iS is uprated to manage higher torques than the ‘029’ model used in the 4.4i. These two transmissions aren't therefore interchangeable either.

Phil

IanP · #10 10-22-2012, 02:37 AM

Try dropping the sump pan doing an oil and filter change on the box. If there is a major problem then you will see the debris, and if it is toast then you will have only wasted a bit of time and money.