98 Caravan Transmission

My van was not responding in traffic this morning. I made it home with the "overheated" light on and barely shifting. Actually it only moved after a rough shift and a wjile after pressing the gas pedal.

When I got home, I figured out that there is transmission oil in the coolant bottle or container (I don't know what to call it). I freaked out!

How did this oil find its way in there? In your opinion, whoever is reading this, will I need a new transmission?

Any input is appreciated.

Jorge

Thanks for the reply.

I actually rolled a piece of newspaper and stuck it inside the plastic coolant container and when I pulled it out it was oily. This after I had put some fresh coolant earlier because I thought it was low and perhaps that was the reason for overheating.

Not only it's obvious that it is oil but it is of a red color.

When you say "there is no way" do you mean that there is not connection between the coolant and the transmission?

I believe the radiator has a built in transmission oil cooler that is not seperately mounted. The two transmission oil lines are usually attached near the radiator base. The radiator may be what's gone.

I tried checking the trans oil to see if it is mixed with the coolant and the stick comes out clean. It looks as if there is no oil.

I have not moved it because I am terrified. I've placed calls to a couple of mobile mechanics and none has responded yet.

BTW is replacing a radiator a "do it yourself" type of job? I thought of renting one of those big jacks and get on it but I'd like your input.

Jorge

The pressure inside the transmission cooler is much higher than the pressure in the cooling system that is why you have the tranny fluid in the coolant. I would recommend that you have the coolant system flushed to remove the transmission fluid from the engine and radiator. The second thing that will result in longer tranny life and save you the aggrevation of a radiator change is to install an aftermarket transmission cooler. They only cost around $100 and can be installed in your driveway. The cooler in the radiator can be abandoned by plugging the the inlet and outlet holes with pipe plugs of the proper size. This will prevent coolant from leaking out through the transmission cooler.
Hope this helps!

GTP Dad if I interpret your suggestions correctly, the trans cooler stopped working? and also, is there some sort of manual that would walk me through the repairs?

Thank you again

Hi Jorge. Your van may already have a transmission cooler on it. It looks like a small radiator mounted on the drivers side in front of the coolant radiator. You can see it looking through the front of the grill. If it does, the lines may also be running through the coolant rad too. This is done fairly often. If you have a separate tranny cooler and the coolant rad is used also, you can reroute the tranny lines using the tranny cooler only. If you dont have the separate cooler, you can also go to your local junk yard and find a good used factory cooler that will bolt right up with no hassle. If your lucky, you can get the lines with it. It will be less costly.
In case you didnt know, they also make red antifreeze... just a thought for you. I didnt know this till a few months ago. It does sound like your antifreeze has contaminated the tranny. You likely wont see it on the dipstick, you will need to drop the pan off or.. pull of a tranny line( the pressure line ) and run it into a container. Start the engine, put it in neutral and let it pump some tranny fluid into the container. With a larger amount you should without fail see antifreeze in it. It will help to have someone to assist you with this.
In any case, hook up the tranny cooler, and replace the transmission fluid. Hopefully you didnt drive it too far when you got stuck in traffic. Dont use cheap tranny fluid and it wouldnt hurt to add a good additive to the oil. When you replace the fluid, dont forget that the torque convertor holds a lot of fluid and doesnt drain when you take the pan off. Replace the filter too. Ask around or maybe someone in here can tell you how to empty all the oil out. Good luck!

You could try a chiltons or Haynes manual but I doubt they will be very specific on these type of repairs. Actually the cooler didn't stop working it has a hole in it and allowing transmission fluid to leak into the antifreeze. This is a common problem.
As far as installing the aftermarket trans cooler the instructions come with the kit. Most of the vans used for towing have external coolers because they transfer more heat from the transmission than the coolant removes. If you don't feel comfortable doing the repair then you may want to take it to a garage. If you would prefer to stay with the radiator cooler then you will need to disconnect the trans coolant lines from the bottom of the radiator. Open the petcock on the lower right side of the radiator and drain the radiator. Once you disconnect them you will get tranny fluid so have something ready to catch it. Remove the hoses from the outlets on the radiator and then unbolt the radiator support on the top of the radiator and remove the radiator itself. You will also need to disconnect the overflow bottle hose but it should come out very easily. I don't believe on the Caravan the engine mounts are located overtop of the radiator. If they are you will need to support the engine and unbolt them first. After you remove the radiator, drain as much coolant out of the engine and back flush it. Usually most folks remove a radiator hose and the thermostat and reverse flush the entire system make sure to catch all the old coolant. Continue until you get clean water. You may also want to use a radiator flush kit that you can buy and most auto retailers, it will make the job easier.
Reinstall the thermostat, you might want to install a new one and make sure to use a new gasket, you may also want to replace the radiator hoses while you have it this far apart. Reinstall the radiator, connect the hoses, reinstall the trans coolant lines and then refill the radiator with antifreeze. The water already in the block will mix with the antifreeze and should give you a good mix. It will take around two gallons. Once you have it filled start the car with the radiator cap off and allow it to heat up until the thermostat opens.
Watch the coolant level. It should drop as the air comes out of the system. Refill as necessary. Then reinstall the radiator cap. Next refill the transmission with fluid. Use ATF+3 or 4 which ever your van calls for. Top it off and you should be good to go. Regardless of whether you do a new radiator or a cooler you will need to flush the cooling system. The cost will probably be around the same regardless of which way you go. At this point if you have high mileage then a new radiator will probably solve your cooling issue too. I hope this helps you out. Good Luck and let me know how it turns out!

Why not just put in another radiator instead of messing around with a external tranny cooler. The van is 7 yrs old, you probably wont have it long enough to see the new radiator die.

I was just under my '97 caravan an hour ago. The front motor mount is located on the bottom. Swapping the radiator would not be to difficult.

By all means follow GTP DADs advise, use ATF-3. And if you take off the tranny pan. Use a Torque wrench to reinstall. Don't bother looking at the Hayes Manual. There is very little info on this part.

you should replace the rad chances are you have an A604 electronic trans and trans must warm with engine temp there is calculated oil temp program in computor and uses it to modify shift schedulling and this temp is calculated according to coolant temp and that is what keeps trans oil and components at this temperature if defeated trans controller does not know and will still perform certain shifts that could hurt trans if it is not at proper temp rad is very important to maintain proper
engine/trans heat relation and durability

Ok guys, it took me a few days to finally find a mechanic to do the job in my home but I had the radiator changed. It turned out to be a bear of a job and he even had to bring down the bumper.

I'm glad I decided not to do it myself. However when he had finished I had to hear the most feared words: "we got a problem" and he pointed at a leak of coolant which he tells me is the water pump.

He told me that it has to be replaced and while at it why not just replace the timing belt.

Now my questions: Could the overheating have caused the water pump to go bump? or was it the oil mixed with the coolant? I went ahead and purchased the parts but I would appreciate your input.

My 1997 did the same thing and it was the radiator busted inside where the tranny cooler leaked and mixed the antifreeze and tranny fluid had to replace radiator and flush tranny By the way dont drive it till you fix it i made that mistake and know i need a new tranny i did not flush tranny and drove it like that its going to cost me $1500 for tranny to get fixed. Good luck FrankC

Ok guys. I have a brand new radiator, a new water pump, new tranny filter, new timing belt and new various belts, fresh coolant...
Everything has been copasetioc for a couple of days. Bliss might be a better way to describe it.

All of a sudden, I started hearing this whistling sound that sounds like a if I had a small siren under the hood. And once or twice the van hesitated when I pushed the gas pedal.

Any ideas? I called the mechanic and he tells me that it could be the tranny "converter" (?) my first thought of course was: "wadda?" He also mentioned that his labor would be about $400 plus the parts another $200.

Any ideas of what else could be causing this noise?

Thanks again for all your previous responses.

EZFrank previous to having the radiator changed I was terrified to even seat at the wheel. Let alone drive the thing...

Check for a vacuum leak or possibly a water leak at the radiator cap. Does the noise start when you start the vehicle or does it occur when it is warm? Also, does the noise get louder when the car is moving or when you rev the engine? There are a number of things that could be the problem but it is doubtful that you would hear the torque converter as they usually do not whine. The front pump maybe but not the converter. Also how does the vehicle run?

Ok GTP Dad, the sound does get louder when I rev the engine. Earlier today again the gears were not reponding.
When it shifts though the sound goes low again.

I thought that perhaps there is too much trans oil. you see when the mechanic changed the trans filter, he ask me to put a couple more quarters. I heard that this could prevent the converter from cerating enough preasure (?)

That is true. If you overfilled the transmission then you need to remove the excess fluid immediately. The extra fluid will damage the transmission and is probably causing damage to the front pump that is why you hear the whining sound. If you remove the excess fluid and the trans gears fail to respond then you have probably already damaged the internal clutches of the transmission. Also what type of fluid did you use? For this model transmission only ATF+3 or +4 should be used. Some of the old time mechanics like Dexron for Chryslers but that only causes problems.

I used the ATF+3. What is the easiest way to remove the excess? DO I have to bring down the pan? I also have the feeling that when the mechanic "flush" it may not have done a great job because when I examined the dipstick I notice droplets of vapor towards the top.

Ok so I took about a quart and now the level is where it is supposed to be. Should this take a while so that the converter builds up presuure (?) again? or should I get results right away?

Any ideas? I went around the block a couple of times and the whistling noise is still there.

Any thoughts?

The converter should not be a problem since as long as it is full of fluid it will run silently. I hate to be the bearer of bad news but you may need to replace or rebuild the transmission. It is possible that water got into the tranny and damaged it internally. it really sounds like the front pump in the transmission is bad. That is the reason you are seeing moisture on the dipstick and you are hearing the noise. I would make sure that the noise is not coming from another area such as a misaligned belt, a vacuum leak or even bad tensioner on the engine.

Oh man! you are the bearer of bad news and I tell you why I think so...when I drive the gears don't engage properly, sometimes it takes longer than others, sometimes I accelarate and there is no response, as if I was in Neutral.

Really scary stuff uh?