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Discussion Starter #1
Hey all, I've been posting here about a loud humming noise coming from the engine bay area at around 2k rpm. I took it to an Indy shop today that specializes in rovers and they couldn't find anything until I had a tech drive with me to mimic the noise. The tech then concluded it's most likely a transmission issue and quoted me $5000 on a rebuild. I just bought it a couple weeks ago!!!! I took it around the block this afternoon and noticed that it doesn't have any symptoms at all when idrive it in sport mode. If it was the tranny wouldn't it also happen on sport mode? Could it be the driveline? I suspected the drive shaft recall but checked the dealership with my vin and it was done on November 2008. Does the driveline effect the rpm?

Please help! I'm really desperate. (2003 range rover hse with 104k)
 

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Can I just check something? Do you mean 'Sport' mode (revised shift schedule) or 'Steptronic' / manual mode (i.e. you do the shifting)?

Phil
 

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Thinking some more about this, it must be related to the torque converter lock up clutch engagement mustn’t it? I can’t think of anything else that would be affected by simply moving the selector lever across the gate. Perhaps the controlled-slip function has failed and you’re hearing/feeling torsional vibration in the driveline when the LUC is applied (there’s no torsional vibration spring/damper fitted in the 5HP24 LUC and it relies on actively controlled low speed slip to damp this out).

The lock up clutch should only be applied in gears 4 & 5 and will probably disengage when you take your foot off the accelerator pedal in these gears (i.e. overrun conditions). Does this tie up with the noise?

I’m just wondering if there’s a simple way to test this ‘theory’. The lock up clutch is activated by the EPRS4 solenoid in the valve block (marked as number 2 in the photo below i.e. the one immediately next to the main pressure solenoid with the green cap). If you drained the fluid & removed the sump pan you could physically pull off the connector to this solenoid (red & 2 purple wires) and this would prevent the LUC from being activated in gears 4 & 5. The problem is that I’m unsure how the transmission ECU would react to an open circuit on this solenoid. I suspect it may just flag a P0740/1/3 DTC which may or may not then need to be cleared on subsequent reconnection but, worst case, it’s possible it might default the transmission to limp-home (i.e. locked in 4th gear with open converter) which wouldn’t help much.

Phil
 

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Discussion Starter #4
Thanks for your response RRPhil. By sport mode I mean just sport mode with no manual shifting. But I have tried driving with manual shifting and it doesn't do it in manual shifing either. If it was the torque converter or even the transmission itself, wouldn't it door regardless of what mode I'm driving it in? The vibration will happen at different gears, 3 & 4 seems like the sweet spot (usually when im driving at a constant 40 mph at 2000 rpm.) Could the o2 sensors be the culprit? The shop did say two o2 sensor codes came up but they just cleared it and if it came back they'd replace it. If I drive normally up a really steep hill the car also has a big jolt/ shudder for a split second if that can also help diagnoise the problem (however this doesn't happen in sport mode).

I think the indy shop just wants their $5k for a rebuild and weren't to sure where or what causes the noise and vibration. The used dealer I bought the car from suspects it's a driveline problem, but the front differential was done a couple of years ago by the land rover dealer on the recall.
 

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Discussion Starter #5
I forgot to mention, yes when the noise occurs and I let go of the accelerator the noise stops right away, then when I hit the gas it happens again. I don't think it's ever happened in 5th gear.
 

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blkblkrover said:
....If it was the torque converter or even the transmission itself, wouldn't it door regardless of what mode I'm driving it in?
I’m coming from the opposite direction on this one. If it was anything other than the transmission that was causing the noise what possible explanation could there be for the noise disappearing when either Sport or Manual mode are engaged? For example, why might the HO2S sensors cause the issue to occur in ‘Drive’ but then not cause a problem in either ‘Sport’ or ‘Manual’?

Changing into Sport / Steptronic mode means that the transmission ECU reads its upshift, downshift and converter LUC engagement points from a different map which, to me, goes some way to explaining many of the symptoms you’re experiencing. However, what doesn’t fit in with the torque converter LUC idea is the fact that you’re not hearing any vibration at all in 5th gear. That’s true even in Manual mode under load is it?

It’s probably worth pointing out that, if it were necessary, you should be able to get your torque converter replaced for less than $1k – it requires the transmission/transfer box assembly to be removed from the vehicle to provide access but the transmission itself doesn’t require any disassembly. Any competent workshop should be able to do this. The last 5HP24 torque converter that I had remanufactured cost me just over £200 ($300).

Phil
 

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Discussion Starter #7
I apologize for my ignorance, but would a torque converter be covered under a warranty that covers the transmission and its internal parts or is the torque converter a completely separate component?
 

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Good question. Although it's external to the main transmission casing they would be pretty mean-spirited to try to argue that it wasn't part of the transmission. It isn't a 'wear & tear' item and is expected to last the life of the transmission.

Phil
 

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Discussion Starter #9
Phil, you've been a great help! Thanks. I'm scheduled to drop off the car at the used dealership tomorrow but I had a feeling he's going to blame something else besides the transmission and engine to void the warranty. I feel stuck because it's hard to prove what it is until something breaks. Ill see what they say but I'm sure it won't be good for me. Ill be taking the rr to the dealership next week for a transmission flush and see if anything comes of it.
 

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Discussion Starter #10
thought I'd update the forum here. Dealership couldn't find anythig wrong so I took it to another independent shop that seemed more honest then the first one I went to. They did a transmission fluid flush and the humming went away and car drives great. They also said only the control arm bushings ned replacement later on (because you can hear a clunk going over bumps). The first Indy shop told me I needed a new $2500 rack and pinion (not to mention a $5000 transmission rebuild). I hope it stays running well. Thanks for all your help.
 

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Discussion Starter #11
So it's been a month since the flush and the noise gradually started coming back. The first few days were excellent and didn't hear any noise. A week later it would happen once a day, now I hear is whenever I'm crusing at 1.4k rpm. So to narrow things down a bit:

Noise now occurs at 1.5 k rpm rather then 2.0 k rpm.
The noise doesn't happen in the morning, it takes 5-10 minutes of driving before the noise starts.
The noise comes and goes as it pleases.

So it seems like the transmission liked the new fluid for awhile but as perhaps the fluid started getting slightly thinner as it was getting older, it didn't like it. Should I drain the pan and refill it with new trans fluid? I checked for leaks and no leaks I can see. Do you think it isn't the transmission and maybe I need a tune up (is it misfiring/missing a cylinder?) the car feels a little sluggish.
 

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I bet the torque converter bit the dust and its slowing letting crap into the transmission. Had one exactly like that and it was ruined when the torque converter let loose.
 

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Discussion Starter #13
I hope not, during the trans flush they didn't mention any abnormal metal flakes in the fluid, just that it was bit burnt. I'm going to try having the front and rear differential fluids changed to see if that helps any.
 

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I just had my tranny remanufactured by Auto Sports Unlimited (the company my ext. warranty company approved to do it) and installed by my local LR dealer, and I now have this exact same noise described by the OP. I never heard this noise before the reman. One difference I have from what the OP described is that my noise seems to only happen in the final gear. Like the OP, it doesn't happen in Sport Mode (mainly it seems b/c the RPM's are kept higher). Another oddity I've noticed is that when maintaining constant speed with cruise control the noise doesn't happen, but if I disable cruise and maintain the same exact speed manually, then the noise immediately reappears at the same speed/RPM conditions.

I wonder if this is something that can be tweaked by my local dealer with the installation aspects of the tranny or if it is going to have to be shipped back up to Michigan from Mississippi to have the reman company try again. I sure hope not because I'll be out of my RR for at least another 2 weeks if so. Also, I think the finger pointing might get ugly between the dealership, my extended warranty company, and Auto Sports Unlimited. The dealership was understandably not excited about installing a part remanufactured by someone they were not familiar with. I wonder if a new torque converted installed locally could do the trick? Supposedly the reman included replacing the old one, so that might not be it.

Any help you guys could provide would be great.

Thanks,
Cliff
 

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Is this noise appearing with vibration and between 1850-2000rpms?After 2100 disappears?
 

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umitbat said:
Is this noise appearing with vibration and between 1850-2000rpms?After 2100 disappears?
Precisely. Does that point to a likely culprit?

"With vibration" is a good description of the noise. It's almost like the vehicle is riding over a tame rumble strip in the pavement. In fact, when I first heard the noise, I thought it was uneven pavement. When it happened again, I figured out it wasn't the pavement. The vibration is not severe, but noticeable unless the stereo is up pretty loud.
 

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OK
It just happened to me;fuel injectors are not working properly.
I did injectors serviced problem solved.
People think it is the TC but even if you put new TC there problem will not go away.
 

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umitbat, thanks for helping me out here. I see that you have the TD6 engine; whereas, I have the 4.4L V8 gas engine. I wonder if the fuel injectors would cause the same problem (and thus be my solution) with the gas engine? I'm thinking no given the differences in a diesel vs. gas engine.
 

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I know this problem is specific for td6.
I am not sure v8 will produce that much vibration because of injectors but might be worth a check i think.
 
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