I've had this car for about 6 months, and I've been putting a lot of time and work into it, so I hope I can solve this latest problem with your assistance. This forum has been a great resource for my repairs up to this point, but this one is proving more elusive.

Today, while in stopped freeway traffic in the afternoon sun, my 1996 850 GLT Wagon started boiling over, with the temp needle pegged to the top of the red. I was able to get off the freeway and pull over within a couple of minutes of this happening. I then bought some more coolant to refill the reservoir, waited for it to cool down, and drove it home, stopping a few times to let it cool when the needle jumped back into the red. All told, it boiled over three times, and I was probably in the red or very near it for about 10 minutes, although not 10 consecutive minutes.

I haven't seen the needle climb above 3 o'clock until today.

The fan doesn't turn on when I start the car and turn on the A/C, and when I got the car up to speed on the freeway, it cooled right down. So I'm sure it's something with the fan, but I'm having a hard time getting more specific than that. I can't tell if it's the fan itself that is bad, or the thermostat, or the ECT sensor, or possibly something else. I used a wire to ground the little nubs in the middle connector of the fan relay, and I heard a click each time, but the fan didn't start. I can easily move the fan by hand, so it is not jammed.

So I have three questions:

1) Did I do the grounding thing on the fan relay properly?
2) How likely is it that I did serious damage during the 10 minutes that I drove it hot?
3) Based on what I've said, can you tell which component is faulty?

Right now I'm leaning toward the whole fan being broken, because of the clicking I heard when I did the grounding test. But I'd really appreciate some expert advice from anybody willing to give it.

Thanks,
Nick

 

Also, my check engine light is on, but my code reader doesn't see any codes.

 

Update: I connected the fan directly to the battery, and it runs just fine. Since the fan didn't run when I grounded the connectors on the relay (with the car running and the A/C on), I now suspect that the relay is the culprit. Am I right? Should I go ahead and order one?

 

I ordered a relay from FCP, and it should be here in 3 days or less with the rush shipping. I'll update this post when I get the new one hooked up.

 

Got the relay today, but that doesn't seem to have fixed the problem. Is there maybe a wire that could have shorted out, or a fuse I'm missing?

 

Hey man, I'm surprised that you have not gotten any replies.

Overheating a car and driving it for 30 seconds is to long. I would be shocked if you don't have a warped head. The car will likely overheat all the time from now on until it totally blows the motor which will be sooner than later.

You really need to stop driving it until you get it fixed. The more you drive it the, more damage you're doing. Soon you'll need a new cat from all the coolant blowing down the exhaust.

At a minimum you will need to pull the head and send it in to be rebuilt. You're looking at a $2,000 min bill at a shop and $800 bill if you do it yourself.

The way I see it you have 3 choices:
1. Get the motor rebuilt.
2. Get the motor replaced with a used one.
3. Replace the car with one with a good motor.

 

Some times to diagnose you just need to be able to get in there and poke around. The relay has power coming in, a control circuit and power to the fan. Have you researched the relay leads to know which is power in and power out of the fan relay ?? If so can you jump them and does the fan come on ?? If it does it's likely a bad relay or even a bad new relay. If not you need to check the power in to see if you do indeed have 12 volts getting to the relay. You could also try supplying 12 volts to the relays lead that goes to the fan to see if when jumped the fan comes on letting you know the wiring from the relay to the fan is good. I'd take a test light and just go through all the fuses and make sure there isn't a dead one in there no matter what it's labeled as. I'm getting lazy in my old age and replaced all my fuses with the "glow when they blow" style. They have a little LED in them and when the fuse blows the LED lights up to indicate the culprit. It is handy to just open the cover and glance at the panel and know they're good.

It wouldn't be a good way to fix it but for a temporary repair to keep you from doing any further damage by overheating it you could run a fused hot lead from the battery to a switch inside the vehicle and back out to the fan and just have an on off switch to turn it on each time you drive.

 

I haven't driven it since it overheated the other day, except to move it from one side of the street to the other to avoid street-sweeping tickets. Actually, last night I did drive it around the block with the new relay in to get it up to normal temperature to see if the fan would come on. It didn't.

I'm actually surprised at the sensitivity of this engine to heat. I hear the word "bulletproof" thrown around a lot with these engines--but I guess even a bullet can melt. But, given your certainty on the matter, I suppose that I'd also be shocked if I didn't do damage to it. But before I replace the car or rebuild the head for a bunch of money, I'd really like to try and get the fan working, take it for a drive, and see what happens.

Thanks very much for your responses on this thread and my other one on MVS (link: http://www.matthewsvolvosite.com/for...49526&p=245924). I added a few more posts to that thread. I'd really appreciate any more input you could give me.

 

I did inspect all the fuses visually, and they all look good. Is it worth buying a test light? Those light up fuses sound pretty rad, but from what RSPI says above, it looks like I'll likely be buying fancy fuses for the next car instead of this one. But don't write me off yet, please!

I have tried jumping the fan directly, and it spins freely. I also tried grounding the middle connectors of the relay (which connect to the yellow and yellow/white wires) and I hear a clicking, but the fan does not engage. The new relay behaves the same. So maybe the new relay is broken, too, but I'd like to be sure before I order a replacement.

That leaves the single red wire, which from the diagram I saw appears to pass through a fusible link before becoming a green wire that is connected to the starter motor. It looks like I'm getting 12v through the red wire, so I don't think that's the problem, either.

Thanks for your help.

 

If the fan works and the relay is clicking the problem is in the heavy gauge wire that carries 12V from the relay to the fan. Can you dismount the fuse box and take a look at the bottom of it? You'll probably find a corroded/melted/something like that wire crimp at the fan relay socket. If not, follow that wire from the fan relay to the fan, see what you find.

Also, I wouldn't be so sure about the warped head yet. Get the car running again and see what happens.

 

I think it's amazing that the car still starts and runs. Aluminum heads warp pretty easy. Coolant boils at about 275° in a well sealed system. My guess is that the red on the temperature gauge starts at 250° and maxes out at 275°. If you don't have head damage you are one blessed dude.

The question I have is what made it overheat in the first place? The fan? I guess that's possible but my fan rarely comes on. I'm not stuck in LA traffic either.

If I were you I would take the car for a drive when traffic is hopefully not a problem. See if it tries to overheat. Have someone on standby that can come get you in case you break down. If the car runs fine, doesn't try to overheat, no smoke out of the tailpipe, and the coolant reservoir doesn't try to overflow, you likely have a chance. Get the fan situation fixed and drive on. But if the car tries to overheat or the coolant tank tries to overflow, expect to have some work done after you get the fan working.

You can also drain the oil to see if there is any coolant in it. Pull the dipstick, if looks like good oil you have a 60% chance that you are good. Coolant in the oil makes the oil look like light chocolate milk. I'm surprised Kiss didn't post his favorite pic yet.

 

I think I need to do something like this tomorrow, so that I don't have to borrow a car again to go to work on Friday (LA is not a good place to have a broken car). I'm worried about burning something up, though. Can you be any more specific about the gauge of wire, the amps of the switch, or the amps of the fuse? I don't want to guess wrong.

I actually did buy some wire and a little switch the other day in case I needed to do that, but without a fuse of some kind, I'm afraid of it melting.

Thanks.

 

When you say the "heavy gauge wire that carries 12v from the relay to the fan," are you talking about the wire from the starter to the relay, or the wire from the relay to the fan? I think both of those are okay, since I read 12v on the wire between the starter and the relay, and since the wire from the relay to the fan is what I jumpered to make the fan run. Am I missing something?

So that clicking noise in the relay means the relay is good?

Thanks.

 

It was almost definitely the fan stopping that caused it to overheat. Since I had been in traffic for about 20 minutes at around 2pm in direct sunlight in a black car, it was primed to overheat just as soon as the fan died. Once I made my way out of the stopped lanes and onto the offramp (which was unusually long owing to construction), I was able to get it going fast enough that the air cooled it so that the needle was almost back to it's normal 3 o'clock spot. But of course it heated up again when I had to stop at the end of the offramp. When I got back onto a different, fast-moving freeway after letting it cool down for an hour or so with the hood open, it stayed cool thanks to the airflow.

Right now the oil still looks clear and golden (I changed it about three weeks ago), no chocolate milk yet. So I guess that gives me a 60% chance I'll take it on the freeway late tonight when there's no traffic and it's cold out to see how it drives. If it doesn't smoke, doesn't overheat, doesn't overflow, and drives okay, I'll consider myself lucky. I guess I'll check for chocolate oil again afterward, too.

Thanks for the good advice.

 

As for the fan, it usually runs full time when the ac is on, which is ALL THE TIME here in 90°+ heat every day. So, I would just jump the fan and drive the car until I could figure out why the fan is not coming on.

 

I agree, but I'm afraid of it melting something. What do I need to do to make sure that doesn't happen, wire-wise, fuse-wise, and switch-wise? I bought some wire and a switch last week, but I could feel the wire getting hot, so I got uneasy and stopped.

 

IDK, I would just run some 16 gage.

 

That's good enough for me. 16 gauge it is. I should run the positive to the battery, and ground the negative, right? Or since it already has a ground, should I run both to the battery? Sorry if this is unbelievably ignorant.

 

IDK, whatever makes it come on.

 

Haha, okay. Thanks for all the help.