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bobinyelm
02-21-2014, 03:00 PM
Ever since my '05 was brand new, when the eng/trans has not come up to normal temperature, if I approach a modest hill in 3nd gear (at low speed and modest throttle), instead of shifting DOWN to 2nd gear, the transmission shifts UP to 4th gear and bogs until the RPM hits about 1000rpm, and only then does it downshift to a proper gear.

I asked this once before and was chided with the retort that this was normal, and that's why the shifter has the manual mode for "intelligent" drivers.

I recently had a transmission specialist witness this (never had a a Sprinter tranny apart, but plenty of import transmissions), and he said he'd never see such a thing in his 40 years in the field.

After the trans is up to temp, it seems to downshift normally (if I let it, rather than manually downshift) in the same situation.

This prompts me to ask again if others experience the same phenomenon.
My Sprinter has only 46,000mi since new but is obviously long out of warranty, so I am asking out of curiosity at this point.

Obviously I DO manually shift down when needed, and, in fact, try to never allow the transmission to downshift under load. By slightly letting off the accelerator just before the downshift, they can be made so that they cannot be felt in the vehicle, which hopefully is less traumatic for the transmission.

hkpierce
02-21-2014, 04:23 PM
You must mean this thread: http://sprinter-source.com/forum/showthread.php?t=13551 I see others who reported the same experience, but no chiding - and no solutions.

Mine does not have this pattern. I wonder if a DAD reset of the transmission parameters might help?

bobinyelm
02-21-2014, 04:53 PM
Yeah-
I tried to find that old post (you found) w/ a SEARCH but it didn't come up.
Probably poor search terms on my part.

Was curious if since then anyone had a better answer for the phenomenon.

BTW, I have a print of your posting on changing oil you posted back in 2005 when I bought my vehicle in front of me as we speak.
Was that your young son pouring oil into your Sprinter back then? I'll bet he's driving it now! Time flies.

Still trying to figure out if mis-resetting ASSYST twice forever locks you into losing the ability of ASSYST to allow oil changes beyond 10,000mi.

I managed to screw-up on reset procedure, and the second try took me 12 sec to do (Limit is 10sec published), and since then when I reset, my mileage shows 10,000,
and as I drive it tracks mile-for-mile down to zero. I was told I'd need a dealer "Re-flash" of my ECM to allow me to use the extended drain interval past
10,000mi using the vehicle's oil sensor and program.

I'd been using Rotella T6 synthetic so was OK changing below 10k miles since it was technically an unapproved oil, but now that WalMart carries the Mobil 1 "EuroCar Formula"
approved 0-40 oil, I would like to use ASSYST again. Co-incidentally, when I went to the Rotella T6 my mpg dropped from the 27-28mpg my Sprinter always gave me to the
24-26 mph I have gotten since then (I check mpg w/ a calculator every tank, and the mpg switched like a digital event down by 3mpg when I went to Rotella 5W40 synthetic). I can't believe the oil would make that difference, but it will be interesting to see, anyway.

Do you know if that's true? Is one locked into 10k mi forever if two ASSYST resets are screwed up?

BTW, the "chiding" about just manually shifting WAS on a Forum post, though not sure which one. I used to be on the Yahoo Sprinter Forum, and one other whose name escapes me.
Might have been this one: (That apparently is defunct): http://www.topix.net/forum/autos/dodge-sprinter or
https://groups.yahoo.com/neo/groups/sprintervan/info I got kicked off the Yahoo one many years ago from what I thoght was a rather innocent comment, and am forever barred from re-joining it appears, so I can't go back and look.
I think there was one more Forum I joined and used, but couldn't find it.

david_42
02-21-2014, 05:07 PM
My 2004 has acted like that ever since I got the transmission fluid changed and Amsoil was used for the refill. I suspect Dr. A's transmission modification would solve the problem, but I can't afford to do the service again so soon just to solve an annoying problem.

bobinyelm
02-21-2014, 06:04 PM
My 2004 has acted like that ever since I got the transmission fluid changed and Amsoil was used for the refill. I suspect Dr. A's transmission modification would solve the problem, but I can't afford to do the service again so soon just to solve an annoying problem.

Does yours only do it when cold (like mine), or all of the time?

I have to believe if only cold, it's a quirk common to many of our transmissions. Since our tranny is also used in the Crossfire. I wonder if it does it there, too, or if it's a programming or valving difference due to the different engines.

I never understood why they used our tranny in the Crossfire, since it uses the 3,2 liter MB engine just like my C-320 wagon that has a marvelous 5 speed transmission attached to it.

RedFord77
02-21-2014, 09:21 PM
Mine does something similar when the transmission is cold, although in my case probably from 2nd to 1st. The hill is steep and only half a block from my driveway.

I recently changed my trans fluid, and when I did the level appeared good. I had some RSN and other things, and when I checked the fluid later it was pretty low. I added fluid, and it seems to do less RSN and the unable to downshift until it is about to die thing too.

My theory is that as the fluid warms up, it expands and takes more volume. My theory is that cold fluid not only is thicker, and harder to pump, but takes less space. My theory is that it works better when warm because it can flow into some tiny passage better.

I also want to know the 10,000 mile assyst question. My van often says round numbers like 4000 miles, but always starts at 10,000. It seems to always have round numbers like 4000, 3900. How do I know if my van has assyst? Did all of them?

bobinyelm
02-21-2014, 11:26 PM
ASSYST was an option that I elected to order w/ mine, though perhaps many were delivered to dealer lots with it already installed.

To be honest, I'm not sure how one without ASSYST acts or displays, so I will leave that to someone else.

When my Sprinter was new, I didn't notice 10,000mi to start, though I did see that when I reached 10,000mi it indicated a few thousand more miles. It finally got close to asking for an oil change at about 14,000 mi.

Since my first reset (when I botched it), the counter starts at 10,000mi, but it never re-adjusts, and when I have GONE almost 10,000 mi, the indicator says near zero miles to go before oil change.

The last change, I didn't reset ASSYST just to see what it would do, and after 8000mi of driving on the new oil and filter, it said "-8000mi" when I'd start the vehicle. If the ASSYST was REALLY sensing the oil, I'd have thought it would not have kept saying I was past due (since the oil was NEW).

Since I was not using Mobil 1 European Formula (as the vehicle was factory-filled with), I wasn't sure if my oil change request was because I had inadvertently reset the counter to a hard 10,000mi, or if the "inferior" Shell Rotella T6 Synthetic Oil was telling the oil sensor it was "finished" by 10,000mi.

Not sure if the sensor is that sensitive to differentiate between oils.

Since I just found and changed to Mobil 1 Euro Formula at 46,400mi, it will be interesting to see what ASSYST does, and if I DID screw it up by making 2 attempts to reset it.

Bob.
( I question whether oils are as critical as we're told- Mercedes told me if I used Mobil 1 Extended Life Synthetic rather than Euro Car Formula, my C320 warranty would be voided, for instance. Then there's the matter of felt filters vs paper filters. MB says you MUST use felt for extended drain; Baldwin says they can supply them, but MB says Baldwin filters are not approved for their cars. My dealer says they use only paper filters, and approve extended drain with them. Go figure!)