I started panicking once my oil temp got upto 105 degrees, after a long slog up the Shap summit with an RRS in tow...

Looks like I was worried over nothing

Yes, Range Rovers seem to generate a healthy dose of paranoia in their owners!

Valve block refitted on Wednesday and oil level topped up last evening (always seems to take a road run to circulate the oil properly by which time it's too hot to set the level).

Taking the caravan out today so will see if progress has been made or not.....

Have updated IID tool with a build that gives access to untested values (as directed by GAP) in the hope of being able to monitor the shift control solenoid. It gives access to 101 (ish) parameters for the TCM alone and I spent some time going through them yesterday but can't find anything that looks like it.

The SCS is designated "MV1" in the documentation. Anyone know what the "MV" stands for - might give a clue!

Away all weekend so will update next week. 2008 TDV8 Vogue

It’s a shortened version of ‘Magnetventil’ – the German word for an ‘on-off’ electromagnetic solenoid. The nearest English equivalents are Magnetic Valve, Solenoid Valve, Shift Solenoid, etc.

Phil

Hey elandri

Thanks for keeping us posted.

Did you have any work carried out on the valve block, thus far, or did you send it away just for testing?

If so, did they find anything?

(Sorry if I missed this) 2007 3.6 TDV8

Phil,

I did about 100 miles towing at the weekend and the 3-4 symptom has changed a little such that it's now clear that it isn't the change into 4th that's slow, it seems to be a problem with 3rd gear itself. I took some more traces and have graphed them here (not sure how to get them into this post):
https://drive.google.com/file/d/1AlXSqEwKH...sp=sharing

This would explain why you thought the 3 to 4 traces I took previously looked normal - cos they were!

It doesn't get me any closer to understanding what's causing it though. I believe the only changes that occur between 2nd and 3rd are that the C brake disengages and the B clutch engages. The pressure control currents for both look OK to me so one might suspect that the B clutch isn't engaging correctly. However, it disengages during 4th and engages again for 5th and there's no apparent problem with 5th.

Cheezels, as I understand it Valve Bodies take it apart, replace all the usual internal bits that are known to cause problems, check for any other wear issues, test the solenoids, put it all back together with a new separator plate and then give it a good thrashing on their test machine. I wish I'd known that before I bothered changing the the solenoids - I'd have just taken it out and sent it to them. Great service; quick and inexpensive. 2008 TDV8 Vogue

Hmmm, well none of the clutches/brakes appear to be slipping:

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Well, if the brakes and clutches aren't slipping I guess we have to think that's a good thing! Nice graph by the way.

It hadn't occurred to me how the turbine speed reacts quickly to the change of state of the solenoids but the engine speed doesn't. Obviously the bit in between is the TC but how that can behave differently from one gear to another I don't know.

I'll try to get some screen shots of the 101 parameters tomorrow.

Not planning on towing for a week or so but will try to get some traces solo. Should still be evident. What are the (fewest) parameters to measure?

Further background info. While towing it behaved impeccably (apart from the 3rd gear issue). Silky gearchanges, changing down when it should and no "Transmission Failure" messages despite the oil temp hitting 96C briefly (though not enough hills in East Anglia to give it a proper workout).

After dropping the 'van off I drove it in a more spirited fashion home (20 odd miles) and it was lovely apart from a couple of fluffed changes (up when I wanted down I think - will be more vigilant when I try again) near the end. I read out the fault codes and there was a single P0730 in there but I couldn't correlate the time to an event.

The IID trace was running so I'll have a look to see if I can see it in there. 2008 TDV8 Vogue

Quote:

Obviously the bit in between is the TC but how that can behave differently from one gear to another I don't know.

Quote:

What are the (fewest) parameters to measure?

Unfortunately, I’m a bit snowed under with work at the minute, so I haven’t had the opportunity yet to look at all the IIDTool data that elandri has kindly sent through. I have, however, just had a quick glance at the first light-throttle acceleration run and it’s interesting to see that the torque converter lock-up clutch is completely off in 1st & 2nd gears and is activated while the transmission is accelerating in 3rd gear. You can see on the graph that, from when the LUC is switched on, the engine speed just ‘hangs’ for almost 3 seconds, until 4th gear is engaged. Once in 4th gear the LUC slip is accurately controlled at 4%. In 5th and 6th gears the LUC is fully locked (i.e. turbine speed = engine speed).

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I’ve finally got around to checking through all of the acceleration runs that elandri measured with the IIDTool; two at light throttle, two at medium and three at heavy throttle.

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I’d be more than happy to help. I’ve found this thread very interesting.

Would you mind summarising which parameters need logging with the IIDTOOL and how the test should be conducted, please 2007 3.6 TDV8

Thank you, cheezels. The four parameters that need recording are:

1. Engine speed
2. Turbine speed
3. Transmission output shaft speed
4. Solenoid 6 – Pressure*

Three runs in total, with a different throttle level for each, would be ideal i.e. light, medium and heavy throttle. The accelerator pedal position should be kept as constant as possible throughout the run from stationary up to either a) where the transmission selects 6th gear or b) when you hit the legal speed limit. Data should be saved as a .csv file.

Phil

*In reality, it’s actually current that’s measured and not pressure, but I believe these are the ‘Live Value Names’ used by GAP Diagnostics

cheezels has very kindly provided a set of acceleration-from-rest results from his 2007 3.6 TDV8, measured using the IIDTool.

At light throttle the results look identical to those of elandri’s 2008 3.6 TDV8 i.e. the lock-up clutch is partially engaged in 3rd gear to progressively reduce torque converter slip, acts in controlled-slip mode in 4th gear and is then fully engaged in 5th and 6th gears.

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Aarrgghh!

I hadn't received any email alerts since I sent my data to Phil back in May so have been blissfully unaware of your efforts. Many thanks to you both and sincere apologies for my poor communication.

It's great to have a comparison. Cheezels traces certainly make the big drop-out in LUC current on mine look very strange.

It looks to me that the TC is doing exactly what it's told - it's just being told to do the wrong thing. Or is it not that simple?

After I put the refurbished valve body back in in May the other issues I'd been experiencing seemed to be resolved but in the last month its gone back to its old ways and, as I'm going on hols to Scotland in it in a couple of weeks, I've been seriously considering taking the plunge and buying a shiny new mechatronic unit from ZF.

Does this seem a reasonable course of action in the light of the what we now know or is there anything else I should try first? 2008 TDV8 Vogue

You have tried resetting engine adaptations? It made a huge difference to my S/C when the box was doing strange things.