2000 XC coolant in trans - radiator replacement - P0743 P1618

[DrJammer]

Hi all,

The beloved battle wagon is showing it's age and may be doomed for hospice care. A month back, I tapped the brakes at 70mph and next thing I know, I have flashing arrow and CEL. Codes thrown are P0743, torque converter electrical, and P1618.

I checked trans fluid and not exactly chocolate milk, but tell tale signs of coolant in system are present. slow coolant level drop as well.

My wife wants me spending absolutely no more $/time on this car. I am willing to give a radiator replacement a whirl with the nissen on FCP.

Main question (aside from a guess as to the actual problem). How do I drain and fill the transmission with accurate volumes since there is additional coolant in there? I was fooled originally to thinking my level was fine, but it now looks like the trans fluid level is getting higher.

Do I need to do any hose flushing of coolant system? Am I way off and not even try the radiator replacement?

Thanks in advance.

[abscate]

Once you decide to go for the radiator....

Very little oil probably got into the cooling system - its much higher pressure than the AT. Just idle it with clean water overflowing for 15-30 minutes (YOU MUST WATCH IT THE WHOLE TIME) with the lower hose cracked to flow water out and filling the reservoir with a hose that overflows a bit out top,

For the trans - I would run clean ATF through he cooler hoses (research which is in/out) until it looks fresh - maybe plan on an extra gallon.

If you save that old Nissans, Ill come pick it up and do a post-mortem on it for you..coming through eastern PA next week.

[EstVolvo]

Your wife may be right, depending on how many usable cars you have and what else needs to be fixed on this car.
Before you do anything check out transmission flush write-up:
viewtopic.php?f=1&t=8767&hilit=transmission+flush
You may have to do it couple of times in order to clean it up good. Make sure you get the appropriate fluid in there.

[DrJammer]

I really hope I get to it by next week, but I doubt it. I don't drive all that much, but don't have much other than the family van. I will save it if timing works out. car will end up being donated by July if this fix doesn't work. then I'll ask for key parts takers on this site.

I left some stuff out in my original post. I did a drain and fill at about 165K. I am assuming 1 drain and fill will not resolve completely but all I will need to get back driving after new rad. but if I drain 3.5 quarts of ATF, isn't that high since there is coolant in there?

Could the coolant be getting in another way, like a simple hose fix?

[FLXC90]

Radiator is the key component for these two fluids. A transmission shop can do a glycol test to see if there are still traces of coolant in your trans. (usually for free) Do a drain and fill, take to shop "A" get results. If necessary, repeat and go to shop "B" if you need to not overwhelm their goodwill.

Coolant will degrade friction materials in the transmission, so get it cleaned quickly as you can.

Luck

[DrJammer]

thanks for the tips folks. I'm going to put the wagon on ramps today and order the radiator. When I originally did the ATF drain and fill, I remember reading the forums at length until I scared myself out of the flush method. Should I attempt the flush knowing there is coolant in there?

Is there a proper order? I planned on draining rad, driving up on ramps, draining ATF, replacing rad, replacing ATF, rad flush?

trying to plan it out, since I work 2 jobs during winter and may have to let the car sit on ramps for days at a time.

Abscate, if I get the rad out, I will PM you.

[FlyingVolvo]

No particular order necessary, as long as you don't forget to fill it! It would probably be good to do the flush method with the ATF using the cooler hoses as abscate said, but drain & fills could help initially. Even if it's overfilled with extra coolant, the excess should come out of the pan. I would drain it once, refill (~3.5 quarts), then with the car still on ramps run the car until warm and slowly cycle through the gear selector. Drain and fill again, and it should start looking a lot more like bright red ATF.

For your initial cleaning, you could probably use a cheaper ATF to run through. Make sure to disconnect the battery for a little bit after doing this to try and reset the transmission's computer. If it recovers and seems to be normal, I highly recommend using Mobil 1 Synthetic ATF. It's expensive, but it's kept my 2000 XC in good shape during some pretty severe driving conditions.

[DrJammer]

Hi all, so the radiator came quicker than I expected, so I decided to see how far I could get before the big game tonite. I am as far of the fan removal, and I just don't see how to get it up past the tube/hose in the pic. am I missing a trick? Also, the upper intercooler hose, looks trashed on the end. can I trim down and re-use? are there generics at the box stores I can grab, or is this a special part order? I appreciate any kicks in the butt to get through today. sorry pics are out of order, getting them in the forum at all is about my technical capabilities

[FlyingVolvo]

You definitely should get a new hose, it's done. Looks original!

I can't remember what i did to get the fan out, but I think I removed the charged air hose going to the electronic throttle. That way the fan should come straight up with no interference. There's a single hose clamp holding it onto the throttle. A little hard to get to, but it's possible. Also take care removing the connectors to the couple of sensors on the pipe.

[FLXC90]

as always, he's got a video for that.

here's one that may be more applicable

2nd edit-- after looking through, ETM cars the rad comes out the bottom easier than up and out. and just having the fan loose, I believe it can stay and the rad slides out of the stack.