John writes:
I was given a 2001 Monte Carlo about 1 year ago. I have put on about 10,000 miles (186,000 miles now) and the transmission no longer goes into overdrive. I don’t believe the previous owner ever had the trans serviced. I am thinking I should replace the fluid and filter however I am afraid that could cause additional problems. Any advice?
Sajeev answers:
This question reminds us all that we must service our trannies on a regular basis. And to not be uncomfortable when someone asks for $100 to do the deed.
For an older car in this condition, cracking open the tranny equates to signing its death warrant. The ATF (automatic transmission fluid) is more varnish than lubricant by now, and replacing the fluid (even if you don’t flush it all out) will send the Monte Carlo’s clutches down a short, painful road. And the end of that road is a junkyard.
I’d drive the Monte Carlo until you lose third or second gear. If you love the beast, don’t cheap out and get rebuilt transaxle from a nobody: make sure the rebuilder is an expert on your model, or you’ll likely regret it after the usual 12-month warranty expires.
Bonus! A Piston Slap Nugget of Wisdom:
I shouldn’t make this a GM-only thing, although the hoopla about their “sealed for life” transaxle in the 1997 Chevy Malibu doesn’t inspire long term confidence. American cars are (were?) known for their honest serviceability, and some of us don’t care for marketing spin on a bean counter’s dipstick deletion. Some think it’s a good idea to examine tranny fluid on a regular basis: the penalty for neglect isn’t worth it. In the long run, of course.
[INSERT BEGGING FOR MORE QUESTIONS HERE. MEHTA@TTAC.COM]
Might be as simple as a solenoid.
If you can’t do it yourself, go to somebody that you trust.
Automatic transmission service is wrought with fraud due to the “black box” view of the mechanism by most folks.
indi500fan could be right. A modern electronically controlled tranny can exhibit problems caused by all kinds of things, some of them not even in the transmission.
I had a mid 90s Ford E4OD (160k miles or so) that would jump out of gear at random times. Turned out was not the trans unit at all, but a broken vehicle speed sensor in the differential that would periodically confuse the brainbox, causing the transmission to crawl into bed and pull the covers over its head for awhile.
Get it checked out. With the electronics, there should be some decent diagnostics without the need to tear the thing down. Then you will know.
Could be an electronic issue, I’d check that route first. If not, have it checked out by a good trans guy, but if it’s never been serviced don’t do it now. How long you intend to keep the car and where/how far you drive the car would be the factors to me as to where you get the repair done, if you intend to do anything at all.
A GM certified unit will come with a 3 year/100,000 mile warranty and usually will cost less than rebuilding the one you have if it’s done at the dealer.
If you do it with an indie, do your homework and make sure they’ll give you a decent warranty. Also keep in mind that most places are only going to warranty parts that are replaced, so if they only fix parts related to the problem and then you have a problem with 3rd gear, you may be screwed.
Might be as simple as a solenoid.
But it might not. It’s really, really hard to tell, and trying to figure it out only makes it worse. I spent a lot of time and money on this kind of fishing expedition. It might have been a valve or solenoid. It might have been a sensor. Whatever it was, my Saab was browning transmission fluid in 20,000km intervals because of it.
If you can find a good AT technician, see what they can do without getting armpit-deep into it. If they can’t do anything, Sajeev’s advice of driving until it drops another gear and then getting a known good transaxle is good wisdom.
Automatic transmissions are, in my opinion, evil incarnate. There’s so much that could go wrong so easily and subtley that they’re not worth the grief.
Might not be the same… but….
On my AOXD ford a c clip broke which prevented the overdrive from being engaged. It was a 1 hour repair and cost a dollar.
If the computer codes check out and there are no solenoid failures it could be loose connection or corrosion on the connectors.
Good luck finding an auto shop that can fix this without the usual “it has to come out” story.
If you can’t fix it cheap drive it until it dies.
Is there a factual basis for the fear of changinging transmission fluid a decade too late and unleashing the varnish?
I am aware it is part of the common wisdom but my indie mechanic for my PU (who checks the solenoids first), does not suscribe to it.
Ah yes – transmissions do need periodic service like most mechanical things.
Someone should have told VW this. Remember the MKIV “sealed for life” automatic transmissions? Usually by 80,000 miles the transmission is slipping, and by 130,000 miles the transmission needs replacement.
More than one VW tech told me that changing the fluid late in the life of these sealed transmissions is expensive, and will actually kill the transmission. No tech I talked to was willing to do the job, so I traded the car.
Funny how all current VW automatic transmissions now require regular service intervals…
-ted
First, check the computer for codes even if the check engine light is off. There are quite a few transmission related codes that will be registered in that vintage GM car that will not trip the light. If there’s any codes note them down and look them up. That will probably point you to a bad solenoid. Since at least the late 90’s most auto trannies are electronically controlled using solenoids to control the fluid flow and pressure. Not shifting into overdrive is probably 9 out of 10 a failed solenoid.
Second, after you have the code in hand do some more research on how the problem is fixed. If it is a solenoid you’ll probably find that it’s a matter of removing the pan or a panel and replacing the bad part. The trans most likely won’t have to be pulled, but some suspension or subframe bits might have the be moved.
Now you have enough information to find someone who can fix the problem. I recommend approaching the problem like this because indi500fan says, too many shops take the “black box” approach to automatic trannies and try to scare you into a replacement or full rebuild.
I’ve had two recent experiences like yours.
The first was with a 2004 Buick Century with around 110k miles. It had a hestitation at launch, but never lit the check engine light. I had several conversations over the phone about it with a guy at a tranny shop who waxed eloquently about internal clutch problems or fluid delivery issues. I checked for codes and found P1811 stored, which points to a problem with the pressure control solenoid. My regular mechanic fixed the problem for around $350.
The second was with a 2002 Ford Focus with around 100k miles on it. The transmission would fall out of overdrive. This time the check engine light came on, and the code stored refernced the exact solenoid that failed. It was fixed by the same mechanic for around $250.
Research your problem and go in informed.
Related transmission question. I own a 1999 Honda Accord EX V6 Coupe with 103k miles. Purchased new with 9 miles on the odometer. Drained and replaced transmission fluid at 90k miles per manual instructions (wish I had replaced earlier) and old fluid was still red and didn’t smell burnt. What are the signs of transmission problems with the failure prone automatic used on the 6th generation Accord?
That was one reason why I ditched my Hyundai Elantra. The tranny kept slipping on the 2-3 shift and sometimes it wouldn’t engage drive (at 125k miles). Tried to get it serviced and my mechanic told me the same thing: opening the case at that point would do more harm than good. Best solution, keep the fluid topped off and go easy on it for as long as you can. In my case, I was already in the market for a new car so rather than be stuck with a $1200 job I just got a newer car.
Crawl under the critter and whack the tranny with a hammer or heavy iron bar a few times.
Just do not tell anyone you are doing that since, if misinterpreted, a “hate crime” charge will surely follow.
This is the “PC era,” you know.
Crawl under the critter and whack the tranny with a hammer or heavy iron bar a few times.
I think this is known as temporary catharsis.
We’ve got a slippy tranny in our 2001 Lumina, too. When it starts slipping (I also hear a whine as the tranny speeds up when it gets slippy), I turn off the car for about 10+ seconds (usually at a red light or I pull in to a gas station), turn it back on, and the tranny falls right back into line. It’s the weirdest thing, but it works every time.
On another note, what’s the real repair/maintenance savings of a manual tranny vs. an auto? Does anybody know? Like, if there are 2 of the same cars, one with a manual and one with an auto, which will cost less in maintenance over the lifetime of the car, assuming a conservative driving style? Does it differ if you hammer it? I’ve always been curious as to which choice yielded lowest lifetime maintenance costs.
My understanding is that autobox oil either needs to be regularly changed or left alone.
My reliable indy mechanic won’t change tranny oil for an older autobox. He did so once, and the customer returned two weeks later with a dead autobox. The car was a seven series BMW. Since this guy is honest, it was not a good day at the shop.
could be an electrical issue. the overdrive is a different switch usually (i don’t know the car).
if the tranny fluid has never been changed, I hear it’s a really bad idea to do it now. but I would have a tech go over the overdrive switch wire with a multimeter.
Hey everyone,
Thank you for the replies!
I’m gonna check for codes and if clear then drive it tell it dies.
If my wife ever gets a new job then I’ll replace the Monte sooner.
My understanding is that autobox oil either needs to be regularly changed or left alone.
When my Saab first started slipping on the 1-2, my mechanic was recommending a slow, gradual replacement of the transmission fluid (which was browning by that point) and it did, sort of, make things better…
…until the day it went into limp mode on my wife. She took it to a different mechanic (because she was a long ways away) who flushed it. Then the real fun started. The source of the problem might have been the neutral position switch (known issue), the throttle body (badly fouled) or some other sensor. God knows, but changing the fluid completely did not help.
The transmission in the Monte is pretty much a commodity unit (shared with the Impala, Regal, Century and Grand Prix at least), and should be commonly available. I’d imagine that, if the problem isn’t quick to find, a replacement part should be.
jackc10 : Is there a factual basis for the fear of changinging transmission fluid a decade too late and unleashing the varnish?
Petroleum engineers can go on for hours on this subject, but the top-of-my-head Cliff’s notes goes something like this: over time fresh ATF gets contaminated by sludge/varnish from heat, oxidization, contamination. ATF then loses its slippery factor, and strips the friction bits in the tranny of their material. More to the point: old fluid becomes the glue that holds an old tranny together. Take it out and the tranny goes south in a hurry. This happens over the course of 80-120k, so changing ATF on a regular basis is a good idea.
Might be an oversimplification, but I know the B&B will correct me.
Mr. Monte Carlo, you owe me. I just did you a big favor right now. I checked car-parts.com and sure enough, there are hundreds of lightly used transmissions available for your car. I didn’t know which engine you have, but there are many low-mile trannies for $350 at various junkyards across the country. Assume another 5-6 hours labor to install the trans, and you’re at less than a grand for the whole repair.
But, knowing that, why not drive the car as is until the tranny actually dies?
Two more comments:
1. I am running out of Piston Slap queries, so email me (mehta@TTAC.COM) stuff now! There are no stupid questions…probably!
2. Invest in an external automatic transmission cooler if you plan on keeping your car for 10+ years. Its even more important for severe duty drivers and people who live in hot climates.
Thanks again for your support of Piston Slap.
Contrary to other opinions I would change the oil, filter and clean out the transmission pan.
If you do it yourself that is. Use a synthetic ATF.
You probably have nothing to lose and I don’t believe the old fluid is keeping the whole thing together.
If you take it to a shop then fitting a second hand transmission may be more economical in the long run.
Man, am I glad that I only drive/own manuals. This whole automatic deal seems like an expensive pain in the ass.
Um, its probably cheaper than changing clutches every 70-100k.
Invest in an external automatic transmission cooler if you plan on keeping your car for 10+ years.
Seconded, especially on heavier vehicles that will be pulling sizeable loads. Eg, any minivan or modern crossover. If you tow—ever—don’t even think once about it: get the cooler.
This car may be almost ideal for the cash for clunkers scam.
I don’t have a slipping tranny on my 1992 LS400, but the fluid is a rather nasty looking brown color. Right now, it’s giving me some noticably hard shifts, but those shifts are still a lot softer than most transmissions on other cars. Go figure.
I took it to the Lexus dealer a few months or so back and they absolutely refused to change the fluid for the reasons Sajeev outlined. Express Oil Change wouldn’t do it, either, adding that Toyota Type T-IV isn’t something they usually stock and they’d have to use an “additive” to make the fluid they had in stock up to Type T snuff.
Needless to say, this $1500 auction score will continue riding on the same tranny fluid until either all 400,000 of its miles finally catch up to it or I dump it for a slightly newer model. I was kinda hoping the Cash for Clunkers thing would be offered in cold hard cash :D
I remember looking at the fluid requirements for my (sorely missed) Volvo 760 Turbo and thinking “WTF Type F?? What is that??”
Ah yes – transmissions do need periodic service like most mechanical things.
Someone should have told VW this. Remember the MKIV “sealed for life” automatic transmissions? Usually by 80,000 miles the transmission is slipping, and by 130,000 miles the transmission needs replacement.
More than one VW tech told me that changing the fluid late in the life of these sealed transmissions is expensive, and will actually kill the transmission. No tech I talked to was willing to do the job, so I traded the car.
Funny how all current VW automatic transmissions now require regular service intervals…
People don’t realize “life” isn’t forever, just better than saying “for, well, about 75-100k miles or so.”
John
SFL transmissions = Planned Obsolescence
Dan R : Contrary to other opinions I would change the oil, filter and clean out the transmission pan.
If you do it yourself that is. Use a synthetic ATF.
You probably have nothing to lose and I don’t believe the old fluid is keeping the whole thing together.
Like you, I would also do a fluid drain-and-replace, change the filter, and clean out the pan. But I would use a cheap ATF, as I would likely be doing a couple more short interval drain-and-replace fluid changes soon anyway!
I don’t believe new fluid causes problems, but flushing might. I’d never flush a transmission. It’s drain-and-replace every 30k to 60k miles for me.
While I like to have a dipstick to visually inspect the fluid, I like that the non-dipstick transmissions use a check plug to determine fluid level. Dipsticks can be off, but it’s almost impossible for a check plug to be in the wrong place.
My lifetime bmw transmission fluid only lasted 85K then the transmission failed. Guess the fluid did last a lifetime. Instead of changing the fluid, you change the tranny. It is always better to change the fluid. You might gain overdrive back and get another 15K out of it. Gives you time to save fore a new one. Do not believe the myth that changing it will kill the tranny. It may give you some extra time.
I had an old 79 Monte Carlo back in college. The tranny started to slip so bad, sometimes I couldn’t get it to engage in Drive. I wasn’t aware of the old wives tale of never changing old fluid, so I went ahead and had a shop do it.
drum roll please…
It worked great! Put many more miles on it before eventually trading it in on my first and last Chrysler product. It honestly never gave a lick of trouble again.
I say change the fluid and report back what happens. It’s on its last legs anyway.
Full disclosure: I am neither a Best nor a Brightest, just my one experience.
I would definitely drain and refill the transmission fluid and change out the filters like some others have said. Since replacement transmissions for your car can be found on the cheap, why not at least attempt to fix it?
Drain the transmission but do not flush it. Notwithstanding what a dealer will sell you, flushing is specifically NOT recommended by GM.
You should have the transmission refilled with Dexron VI – the current state of the art in ATF.
If you really want to, you can do a complete ATF change. This is a bit messy, but it is done by running the engine in Park, carefully pouring new ATF through through the dip tube, while draining fluid through the supply side of the in-radiator cooler.
It looks similar to a flush, but is not. It is simply using the transmission pump to blow all of the old out, while the fresh ATF is coming in from above.
Of course, all of this would include a new filter and a cleaning of the in-pan magnet.
I agree with changing fluid yourself. cheap as dirt. Even if you get solenoid to work again
My Mom’s old Sentra started not shifting at all, about 100k, and there was 1/2 of sludge in the pan. Changed it twice in two weeks to get higher % out. Ran fine for rest of life- another 30k.
Toyota Type T-IV isn’t something they usually stock and they’d have to use an “additive” to make the fluid they had in stock up to Type T snuff…
Don’t do that!! The best way to ruin a transmission is to use the wrong fluid. Remember the Chrysler A604 “Ultradrive” disaster? While the early iterations of this transmission left a lot to be desired, much of the problems stemmed from incorrect fluid and service techniques. As an aside, the method of electronic control that the A604 pioneered is still used in many transmissions today. I guess a case of a good idea hampered by insufficient R&D.
I’m fairly sure that trans fluid is not the problem – if it were, it would be acting up everywhere, not just failing to shift into OD. You need to get a scan tool and see what’s inhibiting the upshift. On some cars, a “noisy” throttle position sensor (TPS) signal will prevent shifting into OD (the trans computer thinks you’re goosing the throttle, when it’s just a jumpy electrical signal).
As far as changing the trans fluid goes, I would do it only if the fluid is brown-looking and smells scorched. Also, when you flush out the old stuff (you’ll need to remove the top trans cooler line on the radiator side tank, connect a hose to it, and run it into a bucket … then start the car, put it in N, and pour about 10-12 qts. of new fluid into the trans while the old junk pumps into the bucket) I always add a quart of Trans-Medic, Trans-X, or some other trans “healer” fluid. This will help swell the rubber seals inside the box and keep them flexible. Have done this on several 100K+ automatics and have put 10s of 1000s of miles on them afterward. I think the key has been adding the Trans-Medic to the new fluid.
But, you shouldn’t do a thing to this transmission – leave it as is. Since it’s a Monte Carlo, with the engine revving away in 3rd gear on the freeway, you can pretend you’re Dale Jr on the back straight at Talledaga (and be honest, that’s really why you “bought” this car in the first place, isn’t it?)
Mother’s Day, I had the codes read or tried. AutoZone gave me error message and said to take it to a transmission shop. The code was Cooling Fan 2 failure. I haven’t researched that one yet.
So I’ll take it to a trans shop where I think the owner will check it for free.