So one day I popped the hood with the car still running because I saw smoke, and I noticed antifreeze spilling out the top of the radiator. My resovoir tank was almost up the the MIN line so I started driving home. So I ordered a 100% aluminum radiator, new radiator hoses, and a new thermostat. I installed everything, and the car ran nicely and stayed nice and cool. Then I started noticing my tranny was slipping from 2nd to 3rd and even worse from 3rd to 4th.

Is my tranny always gonna be like this and eventually get worse? I checked the tranny fluid and it was pretty dark. Will changing my tranny fluid fix this? Anything I could do? I cant afford a transmission and labor right now.

Also I have a CEL code for my EGR valve, would that effect anything?

 

Is your MAX a auto?, If your MAX is an auto then have you checked the tranny cooler lines and did the fluid

leak out of the radiator when It busted? Did your MAX ever received an tranny flush or a tranny drain or refill.

If you have at least 100k miles on it and your doing the tranny flush for the first time let it go, because your

car is already starting to slip and If you decide to do the flush your car might not make it out of the

driveway. The EGR is has nothing to do with the slipping for the tranny, but It does have

to do with the emissions and your MPG. Get the EGR cleaned than figure out what your going to do with the tranny.

 

Well I did lose a little tranny fluid when I disconnected the tranny lines from the radiator when I changed the radiator, but not alot, maybe about an eighth of a pint. The fluid was a dark brownish color.

 

Ok, How many miles does your car have I need to know,so I can tell you If you can do the change or not.

 

It has 145k. I bought the car when it had 128k and Ive never changed the tranny fluid. I have no idea if it was changed in the past but the car was treated nicely from the previous owner.

 

manuals dont have fluid silly

 

The tranny fluid should be red pinkish not dark brownish. Do a simple drain and refill and keep your fingers across. (be careful not to under or over fill - patient is your friend.)

 

First off, are you a auto or manual. I am sure your auto but can you confirm this.

 

yes im auto

 

The I30'S only come in auto and If they are manual they had to swapped.

 

False, the I30 touring edition came in auto and manual. The base I30 only came auto. I have an auto touring edition

 

It is really risky at this point, because you don't know If the car has been serviced on or not, so try to get

some records on the car before you do anything, because if you just changed the fluid now all the particles

that are sticking to the tranny are going to get flused out and the fluid will be new and slick nothing for the tranny to grip on.

 

Ok well if I cant change the fluid then what else can I possibly do to make it not slip?

 

Why not, that's the least you (or your mechanic) can do?

 

The scenerio like yours is always risky and most people who took the chance there trannies either started slipping and worse they were not drivable. If you want to get the it changed, which what should have been done at 30k, but It's your call.

 

What is the color of your fluid, dark pink to dark pitched black or brown.

 

Its dark pitched brown. I did lose about an eighth of a pint or a quater pint when I changed the radiator. Would it be risky to just pour about a half a pint of new ATF in without draining the old fluid. I Know the tranny can slip if there isnt enough fluid.

 

If you can really find out how much you lost, than try to put that much back in. Than It should be ok.

 

Ok what is a good brand and thickness I should use?

 

You can change the fluid without worry. What I wouldn't suggest is a power flush.

Did you add any ATF after adding the new rad? Did you even check the level?

You do realize that you didn't just lose the little fluid that dribbled out of the lines, but also the capacity of the trans cooler, correct?

 

A regular drain and refill Is about 5qts, If you want to do that than that

still can be risky. I would probally do the drain and refill a 1qt or 2qts at a

time but that still can be risky, the time frame can be between every 10-12

months to minimize the risk, but It's the least risky than the 5qts change.

 

There is virtually no risk associated with a drain and fill.

 

Ok, so lets say I lost a quarter of a qrt from leaking when I changed the radiator. Now how much did I lose that was left in the OEM radiator?

Should I just add a qrt of fluid to my car?

 

What exactly is so hard about just checking the damn dipstick?

 

I read alot on the org and one of the things I was picking up was that you

should not change the fluid on a car that has not been serviced on before

and If it has high mileage. I know they said not to do the power flush or the

drain and refill. If you decide to change it be careful.

 

Why are you always mad? Anyway, should I check the dipstick when the engine is hot/cold/running/off?

 

So if the engine oil's never been changed, you shouldn't touch it? Or the brake fluid, or power steering fluid?

Power flushing is (IMO) a bad idea regardless of mileage, but again, there's very little risk associated with a simple drain and fill.

 

If you're having a trans issue, why is checking the fluid level not the first thing you did?

Actually, if you saw trans fluid leaking, or had any sort of loss of fluid, checking the fluid is the first thing you should've done prior to driving the car.

Your owners manual will have the correct instructions on how to check the fluid level.

Failing that:

 

ok,now I never said that you should not change the engine oil or the powersteering fluid and the brake fluid, It's all about the chemicals and the heat that kills the tranny and the fluid plus the metal shavings,It's like grinding all the particles away and flushing them.

 

Not specifically, no. However the catch-all statement you used could easily cover those as well. It's all about preventing misinformation for anyone who might read the thread.

Old, overheated, worn out ATF is, essentially, useless. It doesn't lubricate nearly as well, poor oxidation resistance, etc. Not to mention the varnish it can form inside the trans from driving with it for long periods.

It's far better to have at least a drain and fill with new fluid (preferably several, to filter out all of the old fluid) than it is to leave (in this case, clearly) broken down ATF in there.

 

I am with pmohr on this - just don't see what the fuss about the drain/refill. I know some having trouble with flush, so don't do that - but draining? Should be safe! Based on the color you described, the fluid is due for change. You will never get all the old fluid out at once - but it will get better over time. I simply get ATF from Nissan dealer. It costs about $5/qt. Follow the fill and check steps above, you do want to get the level correct. (Over fill is as bad as under!)

 

Okay but if the transmission is already slipping a few hundred RPMs when shifting 2nd to 3rd and 3rd to 4th, and I have a slight under fill and brown fluid, will a drain and fill solve the problem? Or just adding some fluid until its full solve the problem?

 

Have you checked the fluid yet? How 'slight' is it?

Check the levels, if you know that the fluid is low, but you haven't checked for how low it is, there's no point in attempting other diagnoses. If it's the fluid level, good. If not, then start elsewhere.

Though I would drop the pan and take a look at the magnets, I'm guessing that they're going to be completely covered in debris.

 

Ok well lets just say a slight under fill is the problem. Is my transmission damaged forever from driving with the underfill or will it drive normally once I fill it to its normal level?

 

It's impossible to say for sure. Assuming it's 'slightly' underfilled (which could very extensively from person to person), you likely did little damage by continuing to drive it and completely neglecting to check the fluid level.

How long have you been driving it with old, worn out ATF though? It should not be a dark color. You should drain and fill purely because of that, if you want to avoid permanent (or additional) trans damage.

 

I drove it about 80 miles, all easy to moderate driving. The slipping is really scaring me

 

Let's put this way. If your tranny needs a rebuild, neither drain/fill nor adding more will actually solve the problem. But on the other hand, insufficient fluid, over fill or dirty/burnt fluid will cause the slip. Just go check the level with the dipstick (for time you were typing on the thread, you could be done already), then you can decide to add some, drain/fill or even drop the pan for a complete cleanup, or whatever...

 

Reading this thread =

 

Like pmohr said just check your fluid level and top it off. OR drain and fill. Do that before anything else.

 

Dark brown fluid means it is burnt. I would make sure that the new radiator you purchased has internal transmission cooler lines, because it is very likely that you purchased one that does not have said cooler lines and that is why you are suddenly overheating the transmission.

1) Buy an external auxiliary automatic transmission cooler.
2) Drain and refill the transmission fluid, using only OEM fluid, none of that "racing" or "generic" stuff, and install the new cooler at that time. MAKE SURE THE LEVEL IS CORRECT. If you are unsure, get it done at a dealership so that they can assume liability.
3) Consider purchasing a shift kit (upgraded valve body) to reduce internal fluid temperature and correct your slipping condition.

There is a possibility that you will need a new, new radiator and a new, used transmission, but if it is not too far gone you will be able to get by with the procedure I just recommended. Good luck!