Tranny Problem?

B

Be2lose

In title only.
98 mark 56,000

Over the last couple weeks I've been getting a hesitation while driving light on the throttle. Put a load on it or lift off the pedal it goes away. It is at its worst (bad) from 35-55mph, hardly noticeable (but still there) above or below.


It feels like its running out of fuel. I purchased this car with 46,000 miles on it last Dec. I tend to run my tank pretty low before refilling so my first thought it was the fuel filter. Changed it and no improvement.

Could it be the trans.? I’ve been reading about Mercon V and have it scheduled for a flush and filter change tomorrow.

I also just saw the thread about the tps, could that cause a hesitation in such a narrow range?

I wish I could describe it better.

Running out of fuel?
Misfiring?
Tans problem?
 
If you have never had the transmission fluid changed... I would start there. 35-55mph is pretty much right when the transmission shifts into overdrive.

Do you get a shudder that feels like you're going over some rail-road tracks?
 
maxmk8 said:
Do you get a shudder that feels like you're going over some rail-road tracks?
Click to expand...

Not sure. To me it feels like its almost out of gas, a very quick stop-go-stop-go.

Now that i'm thinking about it my pickup felt like this about 25 years ago. The rearend gears were going out- so if I gave it gas and the released I would get a jerk (for lack of a better word).

It feels like that but without the pedal movement.
 
Have you checked the boots and plugs? Mine did weird things like that (albeit at lower speeds) when I had water in the back plug or when the boots were cracked.
 
Yea that would be the next best thing to do, the boots are prone to cracking... local parts stores are going to have a really tough time finding replacements, but they are out there at only $2 a pop or so. So it wouldn't hurt to stock up.

I am assuming you have no check engine light either?

When my boots went my CE light didn't go on either, OBD II is supposed to be like an oracle lol. Go figure.
 
If it ONLY happends at the same throttle position, but ONLY at certain speeds, you can usually rule out any sensors because you're not changing any throttle position, which would change the "way" the engine is running. Spark plugs and boots is a good place to start, expecially with the "age" of the car. I would recommend copper plugs too....steer away from the platinums.

My concern is that the TPS might have a "flat" spot in it causing a driveability issue at the same speed everytime. There is a "miss" in it causing the trans to hesitate, or even the engine to "flutter". Its an easy change and if the boots/plugs don't fix anything, thats where I'd go next.

Before you do anything, get the car scanned, you CAN have codes but NO light.
 
J said:
Before you do anything, get the car scanned, you CAN have codes but NO light.
Click to expand...

Would the codes be there if the battery was disconected?

I took the neg. terminal off to lower the front. I probably did not even drive 15 miles before I checked for any codes. NONE

I am going to drive about 100 miles today, I'll check again this afternoon.
 
The check engine light would no longer be on... but the codes would be stored in the computer.

Also Jesse is suggesting copper plugs, although copper is a better conductor and will probably give you a negligable amount of added performance, I would stick with platinum and change them every 60-100k vs every 30k miles for the coppers.
 
I agree with Jesse - I use the coppers both for the conduction benefit and also why pay more for platinums when I'm really going to make sure my plugs are changed more often anyway. It's not hard to do, and since we've had to take them out for water checks, boot checks, etc., may as well make sure they're gapped properly and replace as needed.
 
Well 113 miles today. Got code P1000 (Drive More).

I took it in for the tranny flush and the Mech. confirmed the code, but also said it is missing on 1-5-and 7. He said that one bad coil pack could screw up others by emitting radio waves. He wants to try switching them around to pin point the bad one.

Seems strange to me, but I do not know much about these new cars.
 
maxmk8 said:
The check engine light would no longer be on... but the codes would be stored in the computer.
Click to expand...



Interseting, the mech. told me that would erase them. I don't know, I think I'll drive more check the codes again disconect the battery and find out.

By the way-I have never used this shop before. So I don't know how trustworthy they are.
 
Be2lose said:
Well 113 miles today. Got code P1000 (Drive More).

I took it in for the tranny flush and the Mech. confirmed the code, but also said it is missing on 1-5-and 7. He said that one bad coil pack could screw up others by emitting radio waves. He wants to try switching them around to pin point the bad one.

Seems strange to me, but I do not know much about these new cars.
Click to expand...


If you have a miss I would pull the coils and inspect! It is very easy on a gen II.

There are NO COIL PACKS on a 1998 Mark VIII, every cylinder has it's own "coil on plug".

Also a transmission flush is not worth much if the fluid that was used wasn't Mercon V. I would check my bill to make sure they used the correct fluid.
 
maxmk8 said:
If you have a miss I would pull the coils and inspect! It is very easy on a gen II.

There are NO COIL PACKS on a 1998 Mark VIII, every cylinder has it's own "coil on plug".

Also a transmission flush is not worth much if the fluid that was used wasn't Mercon V. I would check my bill to make sure they used the correct fluid.
Click to expand...

What would I look for? I'm not even sure what they look like. The mech. want about $250 to trouble shoot.

Opps, I typed wrong did not mean packs.

It is Mercon V and it had not been changed before, 57000 miles
 
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Sounds like what was happening when Trixies car was running rough. the problem was a few cracked coils. Over time moisteure got in it and rusted the coil plates.
 
Also, Trixis car ran ruff because it was missing. I also got the same error code but on different cyslinders. What happens is that on some firings the coil shorts through the hoising to the head cover. The same thing can happen if the boot is ripped or even has pin holes in the wrong places. Every part store by us sells boot boot for $15. Coils on the other hand $60 per arround here. Here are some of the pics I posted earlier.
 

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