Motor Mount, Trans Mount, or A4ld?

Scorpio / Scorpio Cosworth Discussions - Questions, problem resolution, general talk, technical tips and modifications.
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john keefe
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Motor Mount, Trans Mount, or A4ld?

Post by john keefe » Mon Aug 07, 2017 12:14 am

OK, have had chances to drive this Scorpio more, and I'm REALLY impressed with it. As expected, still a couple niggles to work out. So far, the A4ld is predictable, takes a little babying to "ease" into the shifts for caution, but its been doing fine. No issues with OD, sometimes when really hot it will seem to slip or delay between 1-2, and 2-3 under firm acceleration, but nothing I can't deal with for the time being. I still worry its a time-grenade, so I'm pretty cautious with it.

So, when I back off the go pedal, any gear, any speed, I'm getting a "clunk" feeling. Not a noise, but definitely a feel as if something is settling, or "dropping back into place," if that makes sense. Suspects could be the DS & guibo, but it definitely feels like its coming much more forward than that.

I've jacked up the motor, and checked the trans mount in the recent past, and all seem good (ie., no cracks, not a lot of slack). I still suspect the motor mounts (115K miles) need replacing, and/or the transmission mount. Or, there's something going on with the A4ld as load is momentarily removed. I don't know about the latter, but I'm very wary of the A4 anyway. Odds its motor/trans mount related?

brokencase
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Re: Motor Mount, Trans Mount, or A4ld?

Post by brokencase » Tue Aug 08, 2017 1:00 pm

I think you are describing the torque converter lockup "release".
The torque converter is released when you let off of the throttle by sensing the vacuum in the manifold
when the throttle blades close.

There is a little vacuum switch under the air cleaner box mounted to the fender wall.
Check the vacuum line to this switch and make sure there are no leaks.

According to the EVTM. The switch should trip at 15 in hg. You can test this fact with one of those
handheld vacuum pumps that harbor freight sells and placing a multimeter across the terminals
There is a screw adjustment on the top of this switch to set the trip point (under the cap)

One Scorpio owner has indicated that putting teflon tape around the threads of this adjustment screw
can help prevent leaking. But you still must set the trip point correctly with the vacuum tester before driving the car.
Once you have it set close to 15in hg you can tweak it a little either way to fine tune and get the best feel.

BTW, The torque converter lock-up helps save gas by eliminating the slip of the torque converter at cruising speeds.
It can lock up between 3-4 or after 4th. Lockup engagement feels like a light shift.

Also, original switch is unobtainium. However there are aftermarket adjustable vacuum switches available for around $29.
(search ebay for torque converter lockup vacuum switch)

Ed Lijewski
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Re: Motor Mount, Trans Mount, or A4ld?

Post by Ed Lijewski » Tue Aug 08, 2017 3:11 pm

Nice Scorpio converter release vacuum switch available $35 shipped:

http://i60.photobucket.com/albums/h28/P ... irhcpe.jpg

YMMV
Descartes: "Cogito Ergo Sum"
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brokencase
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Re: Motor Mount, Trans Mount, or A4ld?

Post by brokencase » Tue Aug 08, 2017 8:42 pm

...and this is the adjustable aftermarket unit for $29

https://tinyurl.com/y9nurygl

I think if I were to replace mine (and I have thought about it!) I would choose the aftermarket unit over an original since the rubber diaphragm in an original switch is about 30 years old now.

But John probably does not need a new switch, just needs to verify and adjust the one he has.

Couple other A4LD "Longevity Tips"...
Change the fluid and filter if you have not already done so. Make sure you get the right filter. Throw a bottle of LubeGuard Platinum in for good measure.
If you are high mileage (over 100k) then do the transmission band adjustment procedure.
When driving around town I just place the trans in "3" instead of drive. Less wear and tear on the overdrive.
There is a "modulator" mounted of the side of the transmission and another vacuum line going to it. Make sure that
vacuum line is not dried out or cracked.

The one achilles heel is that A4LD front pump seal. Some fail sooner and some fail later. I am fortunate in that the previous owner
of my Scorpio had his go at 40K miles. Dealer replaced under warranty. I am at 77k now.

john keefe
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Re: Motor Mount, Trans Mount, or A4ld?

Post by john keefe » Thu Aug 10, 2017 4:25 am

Thanks Guys,

Great tip on the vacuum switch. Have done all the other A4LD maintenance points you mentioned, among others the band adjustments, new filter, front and rear seals, front pump hole mods to improve fluid flow, added a trans cooler, adjustable modulator, etc., etc.. So, time to check the switch.

Its not like the TC feels it won't release, and then bang, it does, and you feel a jolt. Its more like the engine-trans unit is torquing over during acceleration (rolling too far onto one motor mount), then falling back onto the other mount when you back off. Hence my suspicions about bad motor mounts.

But, I'll definitely try the vacuum switch pressure test first.

In terms of maintenance, also considered(ing) checking governor and solenoids, etc., but the A4 isn't acting up as bad as those issues might indicate. Not willing to do a fluid flush, even by letting the trans pump out the old fluid and draw in new through the cooler lines. 110K miles, and I'm afraid it will make for more issues. Oil is dirty, but doesn't smell burnt, and no metallic pieces at all. The dirt is probably (hopefully) just contamination from fluid left in the TC when I changed out the filter (and before I added the cooler).

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Re: Motor Mount, Trans Mount, or A4ld?

Post by dimswits » Thu Sep 07, 2017 2:12 pm

john keefe wrote: So, when I back off the go pedal, any gear, any speed, I'm getting a "clunk" feeling. Not a noise, but definitely a feel as if something is settling, or "dropping back into place," if that makes sense. Suspects could be the DS & guibo, but it definitely feels like its coming much more forward than that.

I've jacked up the motor, and checked the trans mount in the recent past, and all seem good (ie., no cracks, not a lot of slack). I still suspect the motor mounts (115K miles) need replacing, and/or the transmission mount. Or, there's something going on with the A4ld as load is momentarily removed. I don't know about the latter, but I'm very wary of the A4 anyway. Odds its motor/trans mount related?
In my not so humble opinion, those odds are 100%. Your driver side motor mount is torn, I have seen several of them do it. The top stud and molded in platform pulls right out of the rubber. On acceleration the motor lifts slightly on that side, puling the stud away from the mount body. When you let off, it drops back into place.
Dimitri in NYC
88 Scorpio 2.5 Turbo
89 Scorpio 4.6 DOHC
02 E46 330Ci
14 Fusion Titanum

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Bob Weir
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Re: Motor Mount, Trans Mount, or A4ld?

Post by Bob Weir » Fri Sep 08, 2017 2:04 pm

Dimitri
Hope you're doing well. I haven't seen your posts in all too long. Thanks for all your help in the past.

John
Dimitri is one of the most knowable Merkur people [not to insult anyone else or their comments].

john keefe
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Re: Motor Mount, Trans Mount, or A4ld?

Post by john keefe » Sat Sep 09, 2017 1:48 am

Bob Weir wrote:Dimitri
Hope you're doing well. I haven't seen your posts in all too long. Thanks for all your help in the past.

John
Dimitri is one of the most knowable Merkur people [not to insult anyone else or their comments].
Thanks guys. Another item on my list to check ASAP... which for me never seems to be anytime soon. I'm wondering it that can be related to any clunking when shifting into gears (F/R) while parking. Idle is correct, all vacuum lines fine, etc..

I did test the switch under the air cleaner... tripped ohms exactly as described for proper function in repair manual, so I can check that off and not worry about it.

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milehighXR
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Re: Motor Mount, Trans Mount, or A4ld?

Post by milehighXR » Sun Sep 10, 2017 2:25 pm

I'll add my $0.02

There are 3 different trans filter kits, and some parts stores will try to sell you the wrong one, even though their computer says it's right. Every Scorpio I have seen(early 88, late 88, and 89) has had the shallow, flat bottomed pan. Look at yer pan before you go to get the kit, to make sure you ask for the right kit. Then open the kit to verify, the box looks identical, for the shallow pan, and the next one deeper. I didn't do this once, and got home and had filter on the car(it had been 2 yrs since I dropped a pan) and I just happened to have a deeper pan to stick on.

Always, when towing(if you do any), and in hilly areas keep the trans in 3rd. I rolled into my first Carlisle smoking everyone behind me out with a James Bond smoke screen cuz I didn't know at that time to keep it in 3rd. The stock oil cooler/warmer is not up to the task of keeping the oil cool when constantly going from 3-4-3-4-3-4-3-4... Most Scorpio owners eliminate the stock oil cooler, and place the largest one they can in front of A/C condenser.

Front pump seal is a pain to get right when being replaced. Search my user name, and A4LD, and you should find in one of my trans rebuild threads a procedure that I have found works to guarantee that the front pump seal, seals when you replace it.

brokencase wrote:...and this is the adjustable aftermarket unit for $29

https://tinyurl.com/y9nurygl

I think if I were to replace mine (and I have thought about it!) I would choose the aftermarket unit over an original since the rubber diaphragm in an original switch is about 30 years old now.

But John probably does not need a new switch, just needs to verify and adjust the one he has.

Couple other A4LD "Longevity Tips"...
Change the fluid and filter if you have not already done so. Make sure you get the right filter. Throw a bottle of LubeGuard Platinum in for good measure.
If you are high mileage (over 100k) then do the transmission band adjustment procedure.
When driving around town I just place the trans in "3" instead of drive. Less wear and tear on the overdrive.
There is a "modulator" mounted of the side of the transmission and another vacuum line going to it. Make sure that
vacuum line is not dried out or cracked.

The one achilles heel is that A4LD front pump seal. Some fail sooner and some fail later. I am fortunate in that the previous owner
of my Scorpio had his go at 40K miles. Dealer replaced under warranty. I am at 77k now.
Johnny


1 86 XR aka Naomi- my first love, now project car
1 14 black Fiesta SE aka Fiona- my new DD

DCLXVI

dimswits
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Re: Motor Mount, Trans Mount, or A4ld?

Post by dimswits » Mon Sep 11, 2017 11:08 am

john keefe wrote:Thanks guys. Another item on my list to check ASAP... which for me never seems to be anytime soon. I'm wondering it that can be related to any clunking when shifting into gears (F/R) while parking. Idle is correct, all vacuum lines fine, etc..
Based on this extra information I would actually check something before looking at the motor mount. Pull the aluminum heat shield from under the car and examine the driveshaft coupling (guibo). If it is missing a chunk, that is likely the cause of all of the driveline weirdness you are feeling. As you shift from forward to reverse, or transition from acceleration to deceleration, a fully broken guibo will allow the part attached to the yoke to shift and "bump" into the part still attached to the rest of the driveshaft. The shaft assembly doesn't fall apart because it is located by a pilot in the yoke.
Dimitri in NYC
88 Scorpio 2.5 Turbo
89 Scorpio 4.6 DOHC
02 E46 330Ci
14 Fusion Titanum

dimswits
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Re: Motor Mount, Trans Mount, or A4ld?

Post by dimswits » Mon Sep 11, 2017 11:09 am

Bob Weir wrote:Dimitri
Hope you're doing well. I haven't seen your posts in all too long. Thanks for all your help in the past.

John
Dimitri is one of the most knowable Merkur people [not to insult anyone else or their comments].
Doing fine, Bob, thanks.
Dimitri in NYC
88 Scorpio 2.5 Turbo
89 Scorpio 4.6 DOHC
02 E46 330Ci
14 Fusion Titanum

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