Don't know if it's a problem

D

Detzl

Registered
Hey guys,

I just got my 1998 viii few days ago. Everything seems to be fine but I am not sure if the tranny operates properly since I have never been in a mark viii before i got mine. 1-2 shift is nice and smooth then once it reaches 3rd gear the rpm drop down to 1000rpm. It feels as if it skips a gear and goes to 4th. So i did a test and it looked like this:

Normal diriving: 1-2 the second gear goes in at 2K and accelerates
2-3 rpm drop down to 1000 sometimes 900rpm
3-4 same thing.

I dont know if 3rd and 4th are longer gears designed for economy and that is why the gear drops down to 1000 rpm.

Sprinted driving the the rpm drops higher since the car would shift at aprox 5000 rpm.

Please let me guys know if this is a problem. I am planning to take the car to a mechanic this thursday. Thank you
 
Higher gears shift at lower RPM's, not sure the exact measure for a 98. Should never drop below 1,100 IMO. How many miles does the car have and when was the transmission serviced?
 
Ok I drove it again and it hits about 1000 - 1200. It's still lower than second gear. Maybe its normal. I got 144K and tranny was serviced 10K ago. I want to do an oil change but I don't know if i should flush it.
 
Well I drove mine. At normal aceleration It shifts 1-2, 2-3 & 3-4 all around 2200 rpm. At the up shift it drops to about 1800. The 1250rpm I was thinking of is when I get into OD around 42mph I usually stop acelerating. Alot of the roads I drive are set at 35mph.
 
I know mine goes into 4th gear very early and will hover around 1200-1400 RPM. I don't like it and I will keep it out of 4 gear, but this is mostly when driving under 40MPH. This was with the 93 and 98 tranny in my car. I always thought this was a design issue for fuel economy also, as my mustang used to do the same thing.
 
It is a design for fuel economy. My solution would be to not engage overdrive except when the road allows the appropriate speed.

Or you could get 4.30 gears. :D
 
Its TOTALLY normal, but the way you're explaining it makes it sound bad.

At 27 MPH the torque converter will go into "lock-up" causing the RPMS to drop and make the engine appear to "bog" down.

Its not as simple as driving with the OD off because the converter will still lock-up in 3rd gear, heck, even second on my car!

Its easy, just drive with the OD off and if you feel the transmission appear to shift and the rpms drop just tap the brake pedal just enough to turn the lights on. This will make the converter come out of lock-up and you'll get your RPMs and power back.

I HIGHLY recommend a chip. The SCT 4bank chip is 299 and you will love every penny. Or you can get the SCT Chip which only has 1 program, which you can have them tune it just to fix the transmission shift schedule which cures the horrid lock-up issue.

Basically, like JP (Driller) said, its designed for OLD PEOPLE....I mean...fuel economy, haha.
 
Thank alot for you help guys. Now I don't have to worry about this since it was bugging me alot. Also i have a Limited slip and 3.27 gears sitting in my garage. I know they won't make a big diffirence but still shorteg gear and posi.
 
Detzl said:
Thank alot for you help guys. Now I don't have to worry about this since it was bugging me alot. Also i have a Limited slip and 3.27 gears sitting in my garage. I know they won't make a big diffirence but still shorteg gear and posi.
Click to expand...

If it's 98 LSC it already has 3.27 gears, but if it's a non LSC base model the gears are 3.07's.

With that said.. I'd "pass" on the sct CHIP and go for the SCT Xcal II {not xcal3)
the Xcal II will hold three tunes and will allow you to datalog the PCM {chip wont datalog)

The datalogs help ALOT in diagnosing issues such as you posted above..AND it'll clear the trouble codes and reset the MIL light.
 
i would defintely NOT flush the motor.... unless your talkin ab doin it with fresh oil. (fill and drain a few times). i had a 88 mark vii with the 5.0 and did it at 88k... 2 weeks later the motor developed a knock... very costly repair... high mileage and neglected maintance ='s sludge and while i can understand your reasoning for the flush, the internals are use to it and when disturbed, it can do more harm than good... although the 4.6 liter is a much better motor, i would think twice about dumping anything but oil into it... just my opinion.....
 
Detzl said:
i have a Limited slip and 3.27 gears sitting in my garage.
Click to expand...

3.27's will be a waste of time, honestly, but the L/S is definitally worth slapping in! Get some different gears and call it good. I have an extra differential that you could install the trak-loc and gears in so you'd only have to do the swap rather then have a bunch of down time.

XLRVIII said:
With that said.. I'd "pass" on the sct CHIP and go for the SCT Xcal II {not xcal3)
Click to expand...

I keep thinking Gen 1, hehe. A tuner would be great for the mechanically inclined, but for those that don't know how to do an oil change, it probably isn't the best idea, haha.

jvi said:
i would defintely NOT flush the motor........
Click to expand...

I didn't even see that post, I was trying to figure out WTH you were talking about, lol.

You should NEVER need to "flush" the engine oil (more of a sales gimick), however, running some oil cleaners for 10 minutes before an oil change wouldn't hurt. On cars with sludge build-up, I've ran a quart of ATF through for about 5 minutes and then changed the oil.
 
J said:
On cars with sludge build-up, I've ran a quart of ATF through for about 5 minutes and then changed the oil.
Click to expand...


actually you can run ATF in the motor.. it just doesnt have the longetivity or the anti corrosion properties that motor oil does.
BUT... its a very high detegent high quality lubricant.

friend of mine has a numbers matching 427 corvette, he runs only ATF in the engine and changes it very frequently.
he owns a transmission shop, so he gets ATF very cheap.

you "could" drain all the oil, put in 6qts of ATF and drive the car for a couple of days then drain and change the oil and filter.

when you look in the valve cover of that 427 it looks like a brand new engine that's never been run.

I wouldn't suggest leaving ATF in the engine for more than 100 miles in a "daily driver".
In a garage queen it'd probably be fine.
For cleaning a motor, it's hands down the "high detergent solution" to use.
 
atf is a good idea. but, those flush detergents sometimes are harsh and for a high mileage motor with little to no upkeep, i would b hesitant ab it.... either way, try whatever you think is best.... i guess it has alot to do with the individual car and the way is was/is used.....
 
I would find a place that does a "Fluid Exhange". We had a machine that would swap out 99% of the fluid WITHOUT intermixing it. Find someone that does that and have them use Mercon 5 trans fluid. This will be your best investment!

If you can find a shop that does that, then have them do a transmission service (pan drop and new filter) AND a torque converter drain. This will change out about 75% of the fluid. Again, use Mercon 5. Oh....if you're mechanically inclined, you can definitally do this at home.
 
You must log in or register to reply here.
Back
Top