System which removes excess heat from liquid cooled internal combustion engine. It also helps maintain the engine temperature at a consistent level. The cooling system encompasses the radiator, water pump, thermostat, hoses, heater core, overflow reservoir, and anti-freeze (or coolant).

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14
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8answers
25k views

My car's coolant temperature reaches almost 100 C / 212 F in a fast pace

Today, after a very hot day, I saw that my coolant was almost reaching 100C/212, I pulled over, stopped and took a look over the hood. The very little water that remained in the coolant tank was all ...
11
votes
7answers
8k views

Can radiator cool down a car too much?

Recently they replaced my stock radiator with aftermarket one (at dealership, so I hope they knew what they were doing), and since then I feel that a car is not warming up enough. Even if I warm it ...
11
votes
4answers
137k views

Can I drive a car with only water and no coolant if it has a leak?

Recently, I was informed that a car I share ('02 Nissan Sentra) was close to overheating. I was told it gets close to the upper limit very quickly upon running the car. When I inspected the vehicle, I ...
9
votes
1answer
79 views

Coolant Reservoir

Two questions, One, is there any reason why some coolant bottles are shaped in this way? Two, if this coolant bottle was placed on its side such as in the image below for example would coolant ...
9
votes
5answers
116k views

Oil in the radiator, but no coolant in the oil

The car is a '98 Buick Lesabre with the 3800 engine and about 170k miles. It appears as though some oil was in the radiator, but I haven't seen any signs of coolant in the oil. The water pump recently ...
8
votes
3answers
249 views

Car won't reach operating temperature

Here's a seemingly simple problem - I noticed that the temperature gauge of my mother's 2004 Opel Meriva 1.7CDTI won't ever climb above minimum. I checked the OBD readings to see if it was a defective ...
8
votes
2answers
59 views

Ford Expedition Eddie Bauer 4.6 V8 2003 automatic rpm goes high

When driving, sometimes when I want stop the vehicle, I go to press the brakes, but that time engine rpm goes high, keeping brakes pressed hard, after 5 second engine becomes normal. It goes high when ...
7
votes
4answers
130k views

What happens if I drive without antifreeze in my car?

What happens if I drive without antifreeze in my car (no water / no antifreeze)? This is my main question. I've added some follow up questions that are specific to my situation but for the main ...
7
votes
2answers
10k views

Why would my engine temperature raise from normal to high and drop back down again?

I have a Nissan Micra (UK, 51-plate, 2001 model) that I have been using to drive to work on a daily basis - 10 miles each way a day on a variety of roads - streets, main roads, main roads in traffic, ...
7
votes
3answers
480 views

Blocked water flow in engine?

My dad has a 1993 Subaru Legacy L 2.2L (no turbo) with a perplexing cooling problem. It overheats, and there doesn't appear to be flow through the cooling system. The upper radiator hose is extremely ...
6
votes
3answers
885 views

Golf mk3 TDI has pressure in the cooling system

I have an interesting problem on my VW Golf MK3 TDI. Basically, sometimes the pressure cap on the coolant reservoir lets out some coolant. Here's what I know: It happens when the car is under ...
6
votes
2answers
23k views

Why does my car sometimes blow cold air while the heater is on?

This started about a week ago. I put the heat on and about after driving a couple of miles with the heat on it would randomly blow out cold air. Sometimes if I turned the heat off or switched it from ...
6
votes
3answers
478 views

94' Honda Civic Cooling issues

Here's what's going on: The temperature remains constant on the highway. The temperature remains constant for short trips. The temperature generally remains constant when the car is not moving. (It ...
5
votes
2answers
70 views

Why is antifreeze mixture not as stated?

To keep things short I poured 200ml of concentrated genuine ford super plus premium antifreeze (Ethylene glycol based) within a bowl. Then added 200ml of water to dilute the solution to a 50/50 ...
5
votes
2answers
42 views

Water underneath floor carpet - Mazda Protégé 2002

I just bought a Mazda Protégé 2002 and a few weeks later I noticed a damp spot on the back passenger side floor. Very wet and soaked. Later I noticed the smell grew larger and the vapor on the glass ...
5
votes
2answers
290 views

Ditch water in radiator

I lost a coolant hose going down the road and all my antifreeze was gone. I found a puddle along the road and filled my radiator back up after I fixed the hose. Will this cause electrolysis in my ...
5
votes
1answer
421 views

Blazer overheating in cold temperatures

Sorry, this is going to be a bit wordy. I have lots of details... A few weeks ago, the temperature was in the single digits with a negative wind chill. I started up my 96 Blazer and let it run for 10 ...
5
votes
2answers
653 views

Strange cooling circuit problems in a 1997 vw golf mk3 tdi

Driving across Europe, i noticed the car was using water. I drove slowly and got to the destination. Since then, the symptoms have been getting stranger. The water loss is caused by excess pressure ...
5
votes
1answer
74 views

What exactly is meant by “engine coolant”?

I know that engine coolant is a fluid in the engine used to dissipate heat spots and keep the engine cool in general as the moving parts generate heat. In this context, I would call the oil an "engine ...
5
votes
1answer
527 views

Should overflow tank be filled when replacing coolant?

I have recently fully rebuilt my engine, minus the block and pistons. All the gaskets were replaced, valves lapped, valve lashes tuned etc. I did it because I had an overheating problem and a head ...
5
votes
2answers
6k views

Overheating & coolant loss in 1998 Subaru Outback

I'm having trouble with this vehicle overheating, presumably from losing coolant. The problem is very similar to what's described here: ...
5
votes
2answers
2k views

Changed radiator, now have misfiring?

I have a 1996 Nissan Altima. I had to change my radiator recently because it developed some cracks on the top of the tank and I would have to refill the tank every few days. When I changed the ...
5
votes
1answer
1k views

2005 Subaru Forester XS overheating

While on a roadtrip, the car started overheating with coolant boiling out. We refilled the radiator with coolant, but it kept occurring. We managed to make it back home by having the heater on high ...
4
votes
2answers
8k views

Engine never warms up (actually: it cools down) at highway speeds

I have a 1997 Caravan (base model) and normally on my drive to work and my highway drives in rush-hour, the engine warms up just fine. I took a road trip for work, about an hour and fifteen minutes ...
4
votes
1answer
114 views

How can I test my thermostat?

How can I tell whether a mechanical thermostat works as it should? Is there a test that can definitively tell me if a thermostat is good or bad?
4
votes
1answer
661 views

Washing coolant system with dish soap to remove oil residue

Someone mentioned it is a good idea to wash the coolant system with dish soap to remove residue oil. I was wondering if that is true or can it have any side effects?
4
votes
2answers
83 views

Is it necessary to maintain antifreeze to water ratio?

I had my radiator cleaned and flushed yesterday. The mechanic who did the work advised that pure distilled water is better than using mixture of water and coolant. I checked the manual and it just ...
4
votes
1answer
183 views

Flushing coolant after driving only with water in

If I drive my truck for 30 min with just water in my system, would it be equivalent to just flushing it stationary (the proper way to flush it)? IOW, if I just drive around with a clean water refill ...
4
votes
1answer
632 views

2015 STI White smoke

My 2015 Subaru WRX Sti is emitting white smoke from the exhaust. The smoke smells like burning electronics. When I pull over and open up the hood, I also see white smoke in the engine bay. The smoke ...
4
votes
1answer
40k views

Getting the best results sealing head gasket leak with Blue Devil

The 1998 Subaru Outback I've been having cooling system problems with turns out to have a combustion gas leak into the coolant. I suspected this but couldn't get a test to turn up anything; taking it ...
4
votes
2answers
49 views

Replace Yamaha FZ6 radiator for two smaller ones

I bought the engine of a Yamaha FZ6. I want to use it to run a competition single seater car we are builiding in the university. The engine didn't bring the radiator with it. I would like to ...
4
votes
1answer
6k views

Engine's Normal Operating Temperature

I read in the Motor Oil University article on Bob the Oil Guy's websites that: The automotive designers usually call for their engines to run at 212°F ( 100°C ) oil and water temperature with an ...
4
votes
5answers
14k views

F-150, heater will blow hot, then cold

F-150, heater will blow hot, then cold and then heat gauge will rise to extreme high, will boil over then gauge will drop to normal. Just had it flushed and no change. After driving for about 10-15 ...
4
votes
2answers
413 views

Bad Dashboard Coolant Temp Sensor?

In addition to the coolant temp sensor hooked up to the ECU, I have a second, single wire coolant temp sensor which is hooked up to the dashboard display. When the coolant temp is around 85C, right ...
4
votes
1answer
135 views

Car is heating while Coolant Temp Sensor is normal

I bought a BMW 318i and the car heated twice so far while the coolant temperature sensor is normal. If we exclude the possibility that the sensor is malfunctioning, what problem would cause the ...
4
votes
3answers
2k views

Replaced water pump two days ago…today antifreeze filling up parking space

I have a 1998 Jeep Wrangler. A few days ago, I noticed the engine temp getting higher than usual. I'd checked fluids about a week prior. When I got home and checked fluids, the coolant reservoir was ...
4
votes
2answers
989 views

OVERHEATING 07 grand prix

My car has been overheating bad I took it to auto zone and hooked it up to the check engine thing and they said it was getting to 207 withing 10 secounds. It get hot fast and my heat doesnt work ...
4
votes
0answers
43 views

2006 VW Jetta Diesel won't warm up

A couple of years ago the VW (2006 Jetta) quit warming up. No heat, no defrost, temperature gauge reads cold! I changed thermostat and tested both 'stats at the same time. Both opened right at 195 ...
4
votes
0answers
112 views

2002 Dodge Ram 1500 overheating

I have a 2002 Dodge Ram 1500 two wheel drive with a 4.7 liter engine. It's been overheating so I replaced the whole cooling system: I replaced the condenser cooling fan because its not coming on ...
3
votes
6answers
47k views

What can cause a vehicle to run hot, but not overheat?

Anyway, I have a Grand Am 2003 V6. It only has 80k miles. My car ran great when I got it(used), but at some point it began to have minor temperature problems. It would always run a little bit hotter ...
3
votes
2answers
1k views

How does the heater core work?

How does the heater core work? What are the inputs to the system? What are the outputs of the system? What are some common ways that it can fail?
3
votes
5answers
42k views

Cooling fans not running

Update This question seems to be attracting a lot of views, so I guess a lot of people are having the same problem. Just to be clear, the problem with MY fans specifically seemed to be caused by my ...
3
votes
3answers
327 views

Do cowl hoods actually help with engine cooling?

I've read that cowl hoods used to be the method for air induction for older vehicles with carburetors and that the only purpose they serve for vehicles with fuel injection is for looks. However, I ...
3
votes
2answers
469 views

Should I try radweld on this pipe or just replace it? Mk3 VW Golf

I have a leaking pipe in the cooling system of my Mk Golf. It leaks about a litre in 5 miles. I'm not sure if it's worth trying Radweld with this rate of flow or if I should just try to find a ...
3
votes
1answer
5k views

Coolant spillover tank boiling but engine not overheating

After driving some time, is it normal that the plastic spillover coolant tank, usually attached to the fan housing, that takes boiling overflow, get so hot that you get bubbles boiling out of it even ...
3
votes
3answers
3k views

Pros and cons of using straight antifreeze

I've heard from some people that they use straight antifreeze in their cooling systems and not 50/50. What are the pros and cons of doing that? E.g. does it reduce exposure to corrosion?
3
votes
7answers
45k views

The mysterious overheating honda civic

This is a tale that goes back about a year when I found my very first car. I needed it to commute back and forth to school. When I bought the car it worked great, everything I could have wanted. ...
3
votes
3answers
8k views

Are there any disadvantages to using a “Radiator Stop Leak” product?

I have had a slow leak form the coolant system for a few months, if I drive the car every day I have to top up every few weeks. The car has 200K on the clock and is a VW Passat TDI, I only drive ...
3
votes
3answers
1k views

Coolant still in expansion tank after draining from engine and radiator — BMW E46 (2003 330i)

I attempted to do a cooling system flush today (along with replacement of radiator hoses, water pump and thermostat). After removing the blue drain plug (my car only had one, apparently some cars ...
3
votes
1answer
4k views

Can a blown head gasket cause overheating, without losing coolant?

My 2006 Subaru Outback overheated when my wife was driving. I got to the car that evening and its radiator was pretty low. I refilled it, and the car ran fine for a week. Then it overheated again. ...