Agree it is safer. Good catch.

 

To wrap this up (for the moment anyway):

@ Chuck Schexnayder: When I pull up on the parking brake while driving the red light comes on with the warning: 'Parking Brake On'. Just as expected.

@ Mikey: Yes, when the engine tugs a bit to stop the car (e.g. @30MPH), the RPM's do nudge up just a little

@ millhouse_corfe: What the dealer suggested trying was not a hard reset, but rather a 'reflash'. This apparently is more comprehensive than a simple reset and involves downloading the latest/new software into the TCM and or ECM using the jaguar sds system.

I decided to hold off on this a bit. Why? Because when my car was at the dealer having a low coolant warning looked into (turned out to be air bubbles in the recently refilled coolant system, not a leak), they gave me a Jag XF loaner. This car exhibited the same 'problem' I was complaining about on my XK: the car doesn't want to coast - the engine puts a significant drag on it. So, for the moment anyway, I'm living with the 'problem' on mine.

Thanks for all your suggestions. I'll follow up if/when I have the reflash done.

 

I'm going to comment on this issue one last time. Don't ask me way.

You said above, that the dealer let you drive a XF while your's was in the shop and the same "won't coast" issue was in this car also.

When your driving alone, say at 50 MPH and lift your foot off the gas pedal, do you expect the car to just "coast" along until it rolls to a stop?

Actually, from what you are saying (and I don't intend any negative comments) this is actually what your comments imply. Your expatiations, seem to imply that you are not use to driving a car with an foreign automatic transmission. I say foreign, because maybe cars with an American transmission function differently. I'll have to drive my wife's 1990 Pont. van to see. Hopefully it has an American made transmission.

To prevent going back through all the past post, have you ever tried driving say at 50 MPH and then putting the transmission into neutral? Does it coast then?

I'm only trying to help you determine how your car should act/feel under normal situations and not an attempt to belittle you in any way and I hope you take my comments that way. If you would rather I not answer your post, just say so. Just think about this. Your car is a 2005 model and you drove a much newer car in the XF and you say the same issue was in the newer car--a car with much improved everything. So, maybe your wanting your car, or any car, to do something it isn't capable of. Spending money at a dealer is very easy to do, however, what your charged for may not even exist, but their not going to tell you that.

One thing I would do before I spent any more money, would be to take the car to a reliable (ask around) transmission shop. Don't tell them about what you think is wrong, just ask them to drive the car (go with them) but don't offer any comments on your suspicions) and see if they think something is wrong with the transmission. Tell them something like your planning on keeping the car for a much longer period and just want it checked out. See what they then say. If there is something wrong with the transmission, they spot it. In fact, just to be on the safe side, take it to another shop and do the same thing. A few bucks spent this way will be a hell of a lot cheaper then at a dealer.

Chuck

05/XK8 C.F. 1 of 200

 

If you are determined that it is a transmission problem I would offer an opinion:

You need a new Transmission Control Module before you need internal transmission repair.

Your '05 is in the 'bullet proof' era of these cars and therefore we do not have a lot of feedback experience with these transmissions.

 

I just bought a 2010 XK and I noticed that the car tends to not want to coast more so than American or Japanese cars. I also have a 2012 XF and I haven't noticed this - yet. I will make sure I check the next time I drive it (which may be awhile since I can't pry my better half's hands off the steering wheel).

 

See my posts - my other car is a VDP. Needless to say, it coasts. Not as freely as in neutral, but there is no pronounced drag as there is in my XK or the XF. The XF at low speeds actually puts more of a drag on the car than my XK.

 

The *only* bullet-proof Jaguar:

 

Annoying, isn't it? Saves gas when you coast.

 

Now you've gone too far ;-) with xk8 at about 300hp and a j-gate for shifting these cars were built to 'Run'. I'm not sure where coasting plays into design on a car such as this but I suspect it's down on the list. Drive the car as it's meant to be driven, it'll respect you for it and give you many a pleasant ride!

 

FWIW,

I compared my S-type to two other cars with automatic transmission and found that the speed of the Jag decreases at a greater rate than the other two. Not sure why I never noticed before.

I'm guessing that the OP's car is operating as per design.

 

MediaBob, could it be that you are not accustomed to driving a vehicle with the high compression ratio of the XK8, and are just experiencing more engine braking than you expect?

 

I have absolutely no need for a bulletproof XJ. But I want one, because that's awesome. Preferably in R trim

And, MediaBobNY, I have the same car as you, and I don't *think* it exhibits the same symptoms. But without driving your's and mine back to back, its hard to say. Unfortunately mine is put away for the winter already (27 degrees out currently), otherwise I would take it for a spin and report back.

This is purely anecdotal, and probably not relevant, but my XJSC with the 5.3L V12 definitely coasts better than my XK8 with the 4.2. But there are many, many factors to explain that difference.

Best of luck resolving both your coolant and transmission issues. I've had no low coolant or overheating issues with mine, and I don't think its a common problem with the later cars, so I'll be very curious as to what the resolution is.

Have you looked into finding an indy mechanic nearby vs. the dealer? As these cars age, sometimes the dealers are no longer best suited to service them. Not to mention the cost savings of going elsewhere.

 

That's precisely why I've put this on hold for the moment. I don't know if it's a problem or normal and I have bigger fish to fry right now so I'll live with it in the meantime. I suspect that at some point I'll have the reflash done at the dealer since it's an inexpensive procedure (if they charge me at all).

 

I'll be interested in how this works out for you.

Just a general impression ...

I drove an '01 XK-8 for about 7 years. This car of course had the 5HP series 5-speed transmission. In all that time, the transmission never did anything to even get my attention; it just worked. Never gave it a thought.

The 6HP26 in my '03 XK8 seems to get my attention -- and not in a good way -- most days I drive it. There is the occasional thunk as it drops into 1st, and the shifting between 5th and 6th is sort of lumpy, if you know what I mean. Enough so that I avoid 6th gear altogether unless I'm going to go above 70 MPH, and plan to stay there for a while.

Again, just my impression.

I have not invested in the re-flash. Maybe in the Spring.

 

13mm thick steel floor - hopefully that will last a lot longer than mine did.

 

Coolant system problems sorted (cost: $2,300). I posted the repair invoice in a different thread.

Re: Indy mechanic. I intend to find one but haven't yet.

 

OK, I paid attention to my car today. ( I don't drive it that often) I will say that when you let off the gas on some other cars, it is as though they are not in gear at all, and they do, indeed, tend to "coast". My car, when letting off the gas when in the lower gears, acts more like a car with a manual transmission and I can feel the engine braking. This is not annoying to me whatsoever, it is what I would expect from a "performance oriented" vehicle. I don't know what you are experiencing, but I can tell you that my car does not "coast" as though it is not in gear, as some other cars do when I let off the gas in a lower gear.

 

Does anyone have a table of speed vs up shifts with closed throttle?

Kick down speeds and open throttle up shifts would be interesting also

I also have a 58 thunderbird and the service manual has these tables in the transmission section.

If it is only up shifting to 4th, it will feel like it has considerable engine braking.

 

In this short (1 ˝ mins) youtube XK8 review by Wheeler Dealers (British TV series), at :24 the reviewer makes the comment:

“Naught to sixty in this car would come up in around 7 seconds, which for a car with auto gearbox which is designed to slow ‘em down really, is really quick”.

'Explains everything. Maybe..

 

Having read all of this several times I would say that your transmission is operating as it should. You have no untoward warnings / noises etc & you say the effect is more pronounced on first start & initial drive, correct this is due to the cold oil effect throughout the transmission. If you haven't got into second then the effect is oil stalling in the converter.

Very roughly,
When you start the engine & select drive, output from the engine is directed through the torque converter to the gearbox per se. During acceleration fluid in the torque converter is driven by the impeller through the turbine into the stator & then mechanically into the gearbox. Selecting D has allowed a valve in the box to direct oil into the lines where the shift change solenoids & lock up solenoid can control the changes by pre-set maps in the EAT ECU which gets information from the engine ECU particularly in regard to throttle position & RPM. At constant speed lock up clutch in torque converter engaged & everybody happy.

On De-deceleration you have effectively just selected a lower speed & the maps will operate the solenoids to either slowly reduce speed which affects oil flow through the converter & gearbox thus causing drag or rapidly with associated braking to cause downshifts.

If you select neutral (N) you have operated the control solenoid in the box to bleed oil away from the line to the shift & lock up solenoids thus the gearbox has effectively gone to a null position & the torque converter to a simple fluid flywheel & no or very little drag is felt.

No doubt a transmission specialist will now come on & object to some of the terminology or the fact I haven't mentioned two other solenoids or stall speed etc,
but I still reckon your box is good, these boxes normally let you know in no uncertain terms when they are ill!!