Overheating Topic is solved

Mn10 · Post by **Mn10** » 20 Apr 2019, 22:28

Hi everyone, long time reader, first time poster (I think).

Basically my problem is that my 1994 Volvo 940 overheated last night. My mechanic is closed for the week since we have a few public holidays coming up in succession.

In the day time the fan would keep spinning after engine shut down, but due to lack of time I didn't really check. I loaned the car to someone and at night as he was returning home, he had trouble. Going about 60km/h (over 2000rpm) on a hill the temp needle went right to the red, on downhills and as he was coasting it back, the needle started dropping back again but it stayed on the hot side. He mostly coasted it back, and the drive was about 15 minutes. (Time in the hot zone I would estimate would be around 10 minutes, and on red it would have been maybe a minute or two). There was no smoke or burning smell.

Looks like a ripped hose or broken water pump as I'm seeing coolant stains on the water pump. I'm also seeing a drenched thin black hose that runs to the radiator. The coolant resoviour is basically empty, there is a little but basically empty.

I'm not too worried about that though, I can get that diagnosed and fixed by my mechanic. I am worried about the effects of the heat on my engine. What would be the effects on my engine, and am I looking at a costly gasket fix in the future? Also I hope things didn't crack or warp :/

I'd appreciate any advice and if anyone has a similar experience which they'd like to share and the outcome of it please do.

Post by **DeadEric** » 21 Apr 2019, 08:18

I like to tell people not to let the gauge go over 3/4 to red to prevent damage.

I could tell you horror and miracle stories about over heating... but the truth is you won't know what to expect till someone looks at it. No sense worrying about "what ifs" more than you have to for the next week till the shop opens.

However, some easy things you can do in the meantime, is fill the coolant. Fill it to the top and leave the cap off. If it goes down right away, check for drips under the car. If none keep filling till it holds steady or starts to drip.

If it drips, follow the drips till you find the leak. If it holds steady, check it from time to time to see if it's gone down.

With head gasket failure, the coolant usually goes into the oil and/or the cylinders. You can note the oil level and see if it rises. Remove the spark plugs and check for pooling of coolant down the holes. Leave the plugs out and the oil cap off (so the air has somewhere easy to go) and check it after a day. You can also crack the oil drain plug and see what comes out. The oil and coolant will separate, the coolant will go to the bottom and come out first. These checks don't rule out head gasket damage if nothing is found but catastrophic damage should be obvious.

Hope this helps, if nothing else, gives you something to do to take your mind off the "what ifs."

tardcart · Post by **tardcart** » 21 Apr 2019, 08:48

since you only have friends observation there is no way to tell duration severity. Most people know to turn the car off if they are lucky enough to glance down and see the gauge in time. This is not a time to limp home. Usually if its in the red, its really way past the red but that's as far as the gauge goes. dont lend old Volvos out I always advise. or any other car. also dont ignore symptoms of water level problems like the fan running.

Mn10 · Post by **Mn10** » 22 Apr 2019, 20:52

DeadEric, Haha yeah, 6 days till it opens. I've parked the car since then, but today I will top up the coolant and do those checks. I have checked the oil levels and the oil, it seems all clean. (The car had just been serviced 2 months ago). I was wondering if it would be ok to refill the coolant drive the car to the mechanic if the coolant does not leak out quickly. Or should I get it towed and let the mechanic get a look? Thanks.

Tardcart, yes I had gotten negligent lately with self maintenance of my car. Now I am in this situation. I will really be kicking myself if there is damage. Unfortunately I had to learn my lesson the hard way :/.

Thank you both for your help and thoughts.

tardcart · Post by **tardcart** » 22 Apr 2019, 20:58

if water is only leaking slowly and the gauge stays cool you can drive it there. skip coolant and use water. take extra with you and use it if necessary.

Mn10 · Post by **Mn10** » 22 Apr 2019, 22:38

Wouldn't only water promote rust? And wouldn't only water heat up quicker? I know more damage may have been already done but haha still.

tardcart · Post by **tardcart** » 23 Apr 2019, 04:22

you dont want to dump a bunch of expensive and toxic glycol on the roadway for no reason. Have you verified it will start?
It can run for a minute with out heating up the engine or hurting anything with no coolant/water.

Mn10 · Post by **Mn10** » 23 Apr 2019, 07:23

Yeah that is a good point about the dumping. It is pretty toxic. I guess I'll fill it with water, give it a start and see if it runs.

Mn10 · Post by **Mn10** » 27 Apr 2019, 04:00

Update: So I went ahead and filled the coolant tank, after 2 bottles, I noticed water gushing out the side of the radiator. I noticed that the plug just under the top hose popped off. Luckily, it had fallen into the engine day and after I fit it back in, the water tank filled up fine. I filled the remainder with actual coolant and started the car. No leaks, car started up fine and seems to run fine. After about 10 minutes I stopped, checked the coolant levels, it was fine. Checked the oil, it seems clean and from what I can see the water and oil aren't mixing.
But even so, I have parked it, I will take it to my mechanic next week and have him inspect it and service the cooling system. See how it goes.

lummert · Post by **lummert** » 27 Apr 2019, 09:38

Maybe drive the car on short errands to determine if there is any permanent damage. I've also had one of those AC fan switches pop out, but I checked to see what was causing the high temp before doing any damage.