J30 Overdrive Problem

[joe_j30]

Hi,

I just purchased a 1993 J30. The car run very smooth, and it has 129k miles. The problem that I'm having is that the car has high rpm on the highway. For example, when i was driving 60 mph, the tach was showing ab little above 3000 rpm. Seems like it wont go to the overdrive. Do you think I have transmission problem? Any cheap fix? Change trans oil & filter? Anything would be appreciated. Thanks.

[VimyJ]

There is no overdrive per se on the J. It definitely sounds like your transmission isn't shifting into 4th gear. You could try a transmission filter change. I might help.

[Eswift]

pretty sure trans wont go into overdrive, or 4th, whatever you want to call it, when the trans temp is still cool. so either, you need to wait until the trans warms up (which it should, rapidly at 3k rpm), or possibly check trans temp sensor for a malfunction.

there is a self diagnostic for all the electrical bits of the trans system, check out your manual.

[joe_j30]

Thank for the help guys!

The problem of my transmission become clearer.1. When I drive on the freeway this morning (the engine and transmission were cold), it was fine. I drove about 65mph, and the rpm is about 2400.2. On the way back from my client to my office (the engine and transmission were hot), the problem started again.

Any ideas? Maybe something to do with oil level because when it was cold, the oil is all the way to the bottom (oil pan)?

Thanks.

[VimyJ]

If your J has never had the filter changed, it could cause a blockage and fluid won't circulate properly.

[joe_j30]

VimyJ,

I think you're right about the car not going to the 4th. I did a gear count, and it only went to 3rd gear. But again, it will go to 4th and od in the morning when the car is cold. I already dropped the car to the dealership, and the will do trans diagnose/service and change the trans fluid. On other thing though. I consult w/ 2 different dealers already, and both of them didn't recommend changing the filter due to the mileage of the car. They said the filter was designed to last a lifetime. They also said that changing the filter would actually exposed the trans to dirt and etc. Flushing the fluid twice might be a good idea though.

Anyway, thanks for the input. I really appreciate it.

[autotech43]

I have had several of the J-30's do some weird intermittent transmission shifting concerns. The most difficult one to duplicate is the transmission temperature sensor that mounts inside the pan to the valve body. You can perform all the ohm test you want and still may not duplicate the sensor when it is at fault.(very intermittent in most cases). In most cases we have found the sensor to malfunction during the first few miles of driving(during warmup). When this occurs the transmission will not upshift correctly(have a mind of its own). The transmission control unit has no clue when to shift, not to shift, repeated downshifts and etc. The only way to perform an accurate diagnose is to have the Consult scan tool attached to the vehicle and perform a test drive and monitor the shift solenoids, trans temp sensor etc. The sensor WILL NOT store a trouble code, so you have to catch it in realtime mode with consult. You may have to leave the vehicle at the dealership as they may have to make numerous test drives under different conditions. The sensor voltage will decrease as the transmission temperature of the fluid rises!

[Eswift]

well, in this case, if i were you

i would:1) get a "complete" fluid exchange. etiher get it done at a fast lub place, or do it yourself.2) if the problem isnt corrected,drop the pan and change the filter.

even if they claim that the filter is "designed to work a lifetime," remember that these transmissions often dont last a lifetime, even when following the reccommended service intervals.

there is always a certain amount of shock to the transmission when fluid/filter is changed after never having been before, but I call BS on the "expose to dirt" claim.

[VimyJ]

The new filter is an improved design. J30s are heavy cars for their transmissions and you need to have the crud scrapped out of the pan, off the magnet and the new filter installed.

"Life of the car" to a dealership is until it comes off the factory warranty. We had a guy come in here with questions about a sun roof. The dealer told him that he should get a new car because of the sticking roof! Beware of dealers. They want to sell cars first and fix them second.

Do a search on this site. There is so much incredible info here that it will change your life.

BTW, Welcome to the one of the best damn sites on the web.

[joe_j30]

Thanks guys. It is by far the best forum I've ever joined. Very quick responses from you guys. Amazing! Thank you for the warm welcome.

Anyway, I didn't really took it to a dealership. I had a mechanic (referred from the previous owner) that has work for infiniti dealers since 1990. He is currently working for a volvo dealership, so I had to drop off the car over there. He ran the diagnostic and found out the problem. Temperature sensor. It's showing that the transmission is cold all the time. He's also gonna flush all 14 quarts and see if the filter need to be replaced. In the meantime, I would have to wait till tommorow morning cuz he hasn't bring down the pan yet.

Anyway, here's my story. This is my first infiniti. I had a LS400 w/ 240,000 miles, and I just sold my SC300 5spd with 168,000 miles. I bought my brother a nissan maxima 2 years ago, and it has approx 140,000 miles. I haven't seen any problem yet, so my guess nissan/infiniti is also built to last. I had 2 hondas before, one of them needed a valve job, and the other one gave up right after i turboed the car.

Again, thanks a lot guys. I will post the follow up in the morning.

[PalmerWMD]

Replace the filter regardless.If it is original it <needs> replacing.I want to reiterate: to drop and clean pan and replace filter.Must be done.

Fred...

[VimyJ]

transmission fluid capacity for the J is 9 quarts. Do you have the mini boxed service manual located in the trunk? It is the J30 bible.

[Q451990]

I'm going to echo several others here and recommend that he go ahead and replace the filter. I don't know how he'd check the filter without doing the pan drop, and I think it has to be dropped to replace the sensor, so just tell him to go ahead and replace it and the o-ring. I can't imagine a reason not to replace it...

Heath

[joe_j30]

I finally got my car back after 3 days.

The transmission is good and smooth now. This is what happened.The diagnostic returned 2 trouble codes:1. Temperature sensor2. Turbine sensor

When the mechanic replaced both parts, they found out that the oil presessure solenoid is broken (they said it could be originated from burnt temperature sensor, and never been replaced for a long time.) Unfortunately, they dont sell the solenoid seperately, so I had to get the solenoid pack (there are 4 solenoid total -> solenoid a, b, c, and the oil pressure solenoid).

The transmission oil is flushed twice (not intentionally), and the filter is very clean, so no need to be replaced. I called infiniti, but they dont have the filter. Instead they have the filter cleaning kit. Any idea?

Anyway, if you guys have similar problems, this could probably help. Actually, the one original problem originated from the solenoid. So in away, I learned a lesson. Fixing trouble codes will not necessarily fix the problem.

If you guys live in Houston area, I can recommend you this mechanic. He's very honest and pretty cheap . He used to work for southwest infiniti since 1990, but he moved to volvo dealership now. Talking about knowledege about infiniti, this guy's been there well over 10 years fixing infiniti.

[PalmerWMD]

Post the # and name of business.

Fred..

[joe_j30]

Sorry, forgot to give his name and number

His name is Curtis and his number (cell) is 713 409 3474.

He is currently working for volvo of houston on I-10 between kirkwood and dairy ashford. I'm sorry, I dont know the exact street address. Anyway, he's on vacation starting today till tuesday (labor day weekend).

[suren]

I have a 95 J30 which will not shift into overdrive. It has 82000 miles.

My question is the locations of:temperature sensor, solenoid, turbine sensor; and are they in the pan or they are under the hood.

I thought there is no filter in the pan. But if it is where can you buy.

I have opened the drain plug and drained for 4 times but have not removed the pan, May be I need to remove the pan.

I am here in Austin, Tx. If you know a good mechanic, please le me know.

Thanks a lot.

[Q45tech]

Even Lexus requires a pan drain [3.5 quarts] and replacement with $8/quart Toyota Synthetic ATF every 30k [2 years] at dealers.......unlike Infiniti which keeps on with the the life time fill.

Dealers [Association] help Infiniti write the US owners manual.......talk about a conflict of interest.

[VimyJ]

Get a replacement filter kit from one of our advertizers. Good prices.

[maxnix]

I am here in Austin, Tx. If you know a good mechanic, please le me know.

Open up your email permission and I will send you to who I use.

[suren]

I have enable email address.

Please give me a shop suggestion.

But first I like to fix it myself such aschanging fileter. Where can I by the transmission filter.

[VimyJ]

I suggested before that you contact one of our advertizers. Everythng Infiniti. Look to the left for their ad.

[suren]

Finally not shifting into overdrive problem fixed. A new filter/gasket and 3 gallons of oil fixed it.

Also, found loose bolt at the magnet. Found the hole and installed the bolt.

The fluid was dark. Can't believe a simple pan drop and filter change made all the difference.

You suggestions very good. Thanks a lot

[Q45tech]

Automatic transmissions are the same basic designs the world over. The fluids and filters have to be changed at frequent intervals, if the design life of 100,000 shift cycles is to be exceeded.

Remember dealers are just a giant parts store who happen to install all the proprietary parts they sell.

They really don't have the engineering depth or inclination or expertise to develop proceedures to maximize component life.