Questions tagged [cooling-system]

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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2answers
7k views

Why are the blades of car radiator fans unevenly spaced?

Fans that look like this: Is it to somehow help the balance of the engine?
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8answers
329k views

Running with straight water as coolant in the summer. Is it fine?

I grew up flushing the coolant twice yearly. In the Spring, you drain the antifreeze and fill with straight water for the summer. In the Fall, you drain the water and put in a 50/50 antifreeze/water ...
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6answers
109k views

Is it Safe to Drive With Low Engine Coolant?

I have a 2001 Chevy Malibu and have replaced the engine coolant in it twice in the last six months after the low coolant warning light came on, and the light has recently come on again. The climate ...
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9answers
72k 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 ...
14
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8answers
421k 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 ...
14
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2answers
2k views

How do I troubleshoot the source of oil in my coolant?

I would like to know the step by step troubleshooting procedure for discovering the source of oil appearing in coolant. There are several different points of failure that can be the root cause for ...
13
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8answers
17k 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 ...
12
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5answers
2k views

Should Multiple Coolant Hose Leaks in a Short Time Worry Me?

Right after fixing another problem with one of my cars ( 98 Mazda 626 GF 2L ), I revved the engine and all of a sudden heard the tell tale hiss of a coolant leak: As you can see, this hose just ...
12
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7answers
139k views

Pros and cons of using straight antifreeze?

I've heard from some people that they use straight antifreeze in their cooling systems, not 50/50. What are the pros and cons of doing that? E.g., does it reduce exposure to corrosion?
11
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5answers
84k 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 ...
11
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5answers
139k views

Why would there be transmission fluid in the water overflow reservoir?

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 ...
10
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3answers
6k views

50/50 Coolant Dilution after distilled water flush?

I have a new (to me) car that it appears hasn't had a coolant fluid change ever, now with 120k miles. It is an 04 Corolla. I am planning on flushing the system with distilled water a few times. But ...
10
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6answers
314k 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 ...
10
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4answers
170k 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 ...
10
votes
1answer
678 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 ...
10
votes
1answer
380 views

Coolant expansion tank issue

My coolant tank is filled up to the correct level before driving off but I've taken a half an hour drive and it is very low and warning light comes on. Once stopped it cools down and the level rises. ...
9
votes
5answers
96k views

How to test if head gaskets are blown?

Is there a definitive way to test whether head gaskets in most engines are blown, without actually reaching for the gaskets themselves (at which point you might as well go ahead and replace them) ...
9
votes
3answers
495 views

Should I get 2nd Opinion on head gasket issue?

My daughter's car had a check engine light on and was overheating. We had it towed to a mechanic and he did the block test with the vapors. The mechanic said the blue stuff turned yellow immediately ...
8
votes
9answers
114k 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 ...
8
votes
3answers
17k views

How long should I wait for engine to cool down before I can check coolant?

I know engine temperature should go down to "C" mark before opening radiator cap. However I'm finding that the temp just stays on normal for a long time. I think I've read people say you need to give ...
8
votes
2answers
34k 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 ...
8
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2answers
16k views

How does the thermostat work?

What happens when the thermostat is stuck open or closed? How does it work?
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4answers
16k views

Should I use the heater while warming up my car?

I know that you should drive off immediately to warm up your car as your entire car will warm up faster this way. However, the common practice to defrost the inside of your windshield is to blast the ...
8
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1answer
601 views

Evans Waterless Coolant

I've seen advertisements for Evans Waterless Coolant and have seen Jay Leno tout it on his YouTube channel. My question deals with the operation of the cooling system after you have properly ...
8
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1answer
985 views

Electric water pump control

Electric fans are now common on cars, both aftermarket and stock. The advantages in horsepower, faster warmup, and hence emissions are well documented elsewhere. The same reasoning can be applied to ...
8
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2answers
2k 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 ...
8
votes
2answers
154 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 ...
8
votes
2answers
805 views

No heat in my 2008 Pontiac Vibe

I changed my thermostat twice in a week on my 2008 Pontiac vibe. My car was blowing cold air and running hot but the thermostat would open up and it would go back down to normal. I would have heat for ...
7
votes
3answers
13k views

Why does my 2006 Chevy Equinox have no heat when all repairs for the heat has been made?

I have: replaced the thermostat about 10 times, back flushed heater core and flushed cooling system out about 10 times, replaced water pump, intake gasket, blend door, mode door, actuators, HVAC ...
7
votes
3answers
978 views

Why does my overheating car cool off on declines?

Thanks for your never-ending support! The quick and precise answers and suggestions that you all provide is priceless in its worth. After the timing belt change ( I skipped the water pump, it looked ...
7
votes
2answers
1k views

1996 Chevy K1500 Silverado ZZ4 5.7L - Rough Idle, Plug Damage, Overheating, EGR

I'm having some serious problems with my truck. It started out as rough idling and then it got worse. I have replaced all 4 O2 sensors, temperature sensor, knock sensor, distributor wires, ...
7
votes
2answers
1k 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 ...
7
votes
1answer
29k 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. ...
7
votes
3answers
612 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 ...
7
votes
1answer
295 views

Excessive Coolant Expansion: Part 3

Part 3 in the ongoing saga of my 98 Mazda 626 2L ATX's cooling system. Here are links to Part 1 and Part 2. A quick recap. My coolant tends to overflow my expansion reservoir. I've flushed the ...
7
votes
2answers
252 views

Coolant in engine… Head gasket going

I have an 05 Equinox, and while idling it sometimes overheats. We have to continously add coolant every week. If this was the only problem, I'd fix it, but, there's other issues as well, and combined ...
7
votes
2answers
825 views

Thermostat behavior and failure modes

If Zaid's excellent How can I test my thermostat? is "Thermostats 101" then this might be the beginning of "Thermostats 201"… My VW Jetta TDI (diesel) has been running cold (about one or two marks on ...
7
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1answer
2k views

How to test the function of a water pump?

Is it possible to test a water pump for proper function (ability to move a certain volume of coolant) without disconnecting it from the engine? If so, how would one do that?
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2answers
18k 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
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3answers
249 views

Engine overheating for short period of time

I recently replaced radiator fan, thermostat and CTS (green one) and my engine is still overheating. The primary suspect is the water pump, but I could use a confirmation so I don't replace a good ...
6
votes
2answers
23k views

Oil Cooled vs Water Cooled

These both are cooling mechanisms. One uses oil to cool whereas other uses some kind of water-based coolant. What are advantages and disadvantages of both in both technical and ownership point of view?...
6
votes
3answers
25k views

Overheating at idle - mechanic says head gasket

My car has been overheating at idle after a long period of time - perhaps 20-30 minutes in traffic. If I drive, it immediately starts to cool down again. I don't drive often so it hasn't been an issue ...
6
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3answers
9k views

Should you change a thermostat when changing your water pump

Just got my water pump changed. Now my thermostat is trying to edge up. Should you change your thermostat when you change your water pump?
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2answers
22k 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?
6
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2answers
20k views

Coolant boiling and smoke coming out of engine bay

I have a 1995 Toyota Camry SE that has 195,000+ miles that has started to develop some serious problems. Aside from what I believe to be an issue with the transmission, the car had been running ...
6
votes
2answers
25k views

How long to wait for radiator to cool down before working on it?

I need to drive my Integra to a friend's place to work on replacing the radiator. It's been 70 degrees lately, is waiting 1 hour long enough to allow the system to cool down? Any rules of thumb for ...
6
votes
3answers
3k 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
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3answers
71k 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
1answer
2k views

Mazda 2 engine fan starts after turning engine off

Apologies for some unclear terms, I have no idea how some of the components are correctly called in english. I have a 2003 Mazda 2 DY gasoline with about 77k KM driven. Since a couple of months, the ...
6
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2answers
17k views

Bent radiator fins — how many is too many?

Hi I thought I fixed some previous overheating problems but I only helped them. My car was running fine when it was 95F or so over the weekend but now it's 110F outside and my cars cooling system isn'...