I posted this before but it did not show up.

My 1996 960 is overheating. Recent work:

1. Replacement of radiator cooling fan. The fan had burned up or failed because of electrical problems. At the time, they did not change out a relay that allows the fan to keep running after engine shuts down. Went this way for several weeks before I noticed the problem. The car was not overheating at that point.

2. Two weeks ago, the AC compressor and other components had to be replaced. This occurred before I realized that the fan relay was not working. So cooling did not continue after engine was shut off. Overheating began right after this point.

3. Fan relay changed out last Friday. Overheating continues.

After the AC changeout, the mechanic told me that there was some weeping from the radiator and I was losing some fluid. The amount was so light that there is no drip on the driveway. Could this small leak cause the overheating problem? The fluid level in the reservoir has not decreased enough to notice.

My questions:
1. Any thoughts on why it's overheating?

2. Is it possible that the fan not continuing to cool the engine and components after engine shut-off could be responsible for the failure of the AC compressor and/or the small radiator crack? I had noticed the fan running after the engine was shut off before any of this work, so I know it did it under hot or high load conditions.

Thanks for your help and your time.

Oscar

You didn't mention any thermostat change. For some reason they seem to have a short life! I've changed mine about every two years but they usually stuck open and were overcooling the engine. (gauge never got to mid-scale)

The first thing I would do is change that thermostat. Drain about 1 liter of coolant and then take out the two bolts holding the housing and replace. Only takes 1/2 hour start to finish. Be sure to note the "up" marking and place the new "O" ring in the same place as the old one.

Since 90% of the present cooling system is aluminum and plastic I believe you will have fewer corrosion issues if you stick with the aluminum radiator. Flush the system good and use Volvo coolant to fill up. Should be good for several years then.
--
'96 965 with 16' wheels at 101K. Had '85 745 Turbo Diesel for 200K.

Oscar:
The exact same symptoms of overheating on my 960 was caused by a bad thermostat. A couple of people mentioned this below, but be sure to change out your thermostat. Cheap and easy to do.

I think you do need to change out the radiator. Importec has a two row metal Nissens for about 220 bucks: http://www.importeccatalog.com/

I also think you should use the volvo coolant, too.

Good luck with this.

Mike Brown
Greenville, NC
1996 965 94K
1986 244 136K

I haven't bought a Nissens rad, only learned about them after my disaster. Most here suggest they are good. Might be a goog idea to post that query. Sorry i can't help more.

I'd find it hard to believe that the fan was responsible for all that, unless it has failed altogether. My cooling fan has never run more than a few/several seconds after shut-off, regardless of the ambient temperature outside.
--
John Shatzer, '97 V90 @ 94K

Are you sure the fan should run after engine shuts down? Mine never did since new.
--
'96 960 74K

Get a new radiator and install it. Use Volvo coolant. Get ALL new coolant hoses and replace them. Two larger hoses, two heater hoses, two oil cooler hoses and the two which go to the overflow tank. Consider getting a new heater valve as well. Check some of the vendors displayed atop these pages. Cheap insurance for a great car.

Most around these parts figure the plastic/AL radiator lasts 10 years or 100K miles. I recently replaced mine due to aging considerations.
--
Warren Bain - '99 V70GLT G-Valve > 70K mi, '96 965 >110Kmi Wifemobile near Manassas Va.. Check the 700/900 FAQ via the 'features' pull down menu.

Oscar:

I have a 95 960 but I've never had this type of problem with it. I have seen this on my Toyota Landcruiser and the problem was a small coolant leak. The leak never produced a drip on the ground but I was able to pinpoint it by stopping engine when hot and lifting the hood and poking around with a piece of tubing held to my ear(poor man's stethoscope). My problem was solved by a little tightening of a screw-clamp on one of the coolant hoses. I hope your problem is as simple(read minor), although it may difficult to diagnose.

Ed
89 245
95 960 85K - for sale

Ed,

Thanks for your answer.

Did you say that stopping the minor leak corrected the overheating? In other words, this lends credence to the mechanic who is saying that the decrease, or release of cooling system pressure causes the overheating.

The leak is a small hairline crack on the top of the plastic portion of the radiator. Don't know whether they can use a bonding agent to seal or whether I will need a new radiator (cost of installation: About $350.) I'm hoping that a cheap fix is possible.

Thanks for your interest, buddy.

Oscar

If the plastic portion is cracking it is time for a new rad. I would not suggest trying to repair the plastic. You will probably find that if you remove the upper rad hose that the plastic there will be ready to let go.

$250 for labor is too high, it takes less than a hour to install. Rad should cost around $200 if you shop around.

A leak by itself will not cause overheating unless the coolant level drops dramatically. That would mean it is not even visible in the reservoir. If you have sufficient coolant remaining in the reservoir that is not the cause.

First stop for any overheat problem is to change the thermostat.

You do not mention when it overheats. Your post implies that it is overheating after shut down. Does it overheat while driving, at speed, at idle?
--
David Hunter

David,

Thanks for your post.

Yes, it overheats during driving with the AC on. If I shut the AC off while driving, the gauge comes back part way. Once the car is stopped and idling, the gauge comes back, but not completely to normal. After that, colling continues. Starting it again shows the gauge is back to normal. If I drive it again, the overheating comes back.

The small hairline crack weeps. There is not enogh leakage for drips on the driveway or for the reservoir to show much lowering of level. There is a bit of pressure build up on the reservoir. If I loosen the cap, there is a slight pressure release and some leakage then. After cooling, not much coolant has been lost.

I have noticed that the small hose at the reservoir is also leaking slightly, but again, the level in the resrvois does not change much even after the car cools.


Thanks.
Oscar

It is normal for the apparent coolant level to go and down a bit, higher when hot lower when cool. Make sure the fan is running when the AC is on. It comes with the compressor after a short delay. You should observe this while at idle. Do not forget to change the thermostat.
--
David Hunter

I have a 95 960, and experienced the exact same problem. In my instance, there was a hairline crack in the upper plastic rad neck. When hot, the pressure forced coolant out in vapour form, so there was no visible glycol. When the engine cooled, there was no pressure and as a result no glycol on the ground or in the engine compartment. The mechanics could locate no leak, until a hot summer day when the upper rad neck blew off! Thank God it was in the city, as I stpped immediately and avoided engine damage. In this example I replaced the rad with new Volvo. I considered plastic welding or high heat epoxy to reattach the neck, but given the approximately $6,000 cost of an engine and valve rebuild if the system blows, $280. for a rad is peanuts. Since then I have learned that a Nissens rad is a better choice, and does not have the weak plastic ends. Hope this helps.

960 Guy,

Did you say a Nissan radiator is available that will fir the 960?

Is it cheaper? Better? than a Volvo OEM replacement?

Thanks,

Oscar

oh yea, be sure to replace the thermostat and top up transmission fluid after the rad change. The transmission cooling lines need to be disconnected to do the rad.

The transmission cooling lines must be filled with coolant and not with transmission fluid like you said. Right?

There are four connections. A small hose at the top left. A larger hose at the top right (all this as I look from the front towards the back) and two hard tubing connections. I assume these hard tube connections go to the transmission.

O.

No, only tranny fluid flows in the transmission lines to the radiator.

There should be two metal lines going from the transmission to the radiator. Inside the radiator there is a small tank that is used as a heat exchanger. It helps warm a cold transmission and cool a hot transmission. When you disconnect these two lines (threaded fittings) usually a few drops of tranny fluid comes out. BTW, a leak in the heat exchanger internal to the radiator is a nasty failure mode, rare but it has happened.

Just check the tranny fluid level after your done.
--
Tom F

960 Guy,

Where do I get Nissan radiator for my 960?

Oscar

Hi, I did not learn about them until after my disaster, so I have the volvo plastic ended rad in now. Many here think highly of them. The Nissens web site is : http://www.nissens.com/. I would e-mail them and ask for a local distributor and receive confirmation that they have one for your car. I have also used modine Gold rads, which come with a lifetime warranty, on my Honda. Not sure if they are available for Volvo's. Might be a good idea to post a query re Nissens, and call Nissens 8700 Horsens - Denmark Phone:+45 7626 2626 - Fax:+45 7564 2205 nissens@nissens.dk. Hope this helps!