An alcohol based fluid that is miscible in water and used to remove heat from the engine. Also see [tag:cooling-system] for related components such as the radiator and water-pump.

learn more… | top users | synonyms

19
votes
7answers
111k 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 ...
15
votes
12answers
79k views

Is Prestone “All Makes/All Models” coolant *really* compatible with all models?

My car's manual says to use the blue Honda coolant: Always use Honda All Season Antifreeze/Coolant Type 2 [MSDS]. This coolant is pre-mixed with 50 percent antifreeze and 50 percent water. ...
14
votes
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 ...
13
votes
5answers
22k views

2000 VW Golf heater won't blow hot air

My 2000 2.0L Golf GLS won't blow hot air at operating temperature, the air is only lukewarm at best. This started a few months ago inexplicably. The car isn't overheating or underheating, it reaches ...
11
votes
4answers
136k 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 ...
10
votes
5answers
3k views

2005 Ford Taurus - Is it really harmful to use standard antifreeze?

My wife was speaking with a mechanic when she took the car in for a safety and emissions inspection this past week and the mechanic told her that we HAD to take our Ford Taurus to a Ford dealership or ...
9
votes
1answer
68 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
1answer
78 views

The purpose of covering the grill during cold weather

In some countries it is quite popular to cover up the front grill in winter (especially on diesel engined cars). As I understand the intention is to inhibit airflow to the radiator, but why would you ...
9
votes
5answers
115k 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
340 views

How to dispose of engine coolant?

This question is pretty straight forward... How to properly dispose of engine coolant? Should it be taken to a treatment facility like used engine oil or is it safe to pour down the drain?
8
votes
1answer
699 views

I'm stupid and added tranny fluid to my coolant tank. What can I expect?

Title pretty much says it all. I'm a computer guy, not a car guy. I saw a bunch of red fluid coming out of my vehcile, assumed it was tranny fluid. Turns out it was antifreeze. This means the bit of ...
8
votes
1answer
74 views

BMW M52 coolant refilling

I have a BMW 328 -98, or in other words, an E36 with the M52 engine. I cannot for the life of me understand how the coolant system works on this engine, and therefore not how to properly top it up ...
8
votes
3answers
215 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 ...
7
votes
4answers
129k 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
3answers
32k views

Oil in coolant - how much trouble am I in?

I have oil in my coolant reservoir. Could it just be the head gasket or is it almost certainly the entire engine or might it be something else entirely? Thanks in advance...
7
votes
2answers
3k views

How can you tell the difference between oil or transmission fluid in the antifreeze?

I am in the process of repairing my 1997 Toyota 4-runner with a v-6 engine. I have only had the vehicle for a couple of days. I was doing a routine maintenance check on all the fluids. What I found ...
6
votes
2answers
23k views

Accidentally poured engine oil into the coolant reservoir

My 1990 Mazda 626 leaks oil like a sieve, so I regularly top up the oil. In a moment of stupidity, I opened my radiator cap instead of my oil cap while topping up my engine oil, and poured about ...
6
votes
3answers
12k views

How do I find a vacuum leak? I'd highly prefer not to use a carb cleaner spray

The car is a 1998 Oldsmobile Intrigue with 3.8L V6 engine (3800 Series). I've been doing my research and due diligence, but please understand I'm very inexperienced with automobiles. I went to ...
5
votes
3answers
2k views

Why would a water pump be run off of the timing belt?

I drive a 1999 Chrysler 300M, V6 3.5L engine. I am about to start a water pump replacement repair. I've discovered that the water pump is driven off of the timing belt, rather than either of the two ...
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
181 views

How, and why, do you test coolant concentration?

In the owner's manual for my 2001 Ford F-150 (5.4L), in the section on "Adding engine coolant", it specifies the type of coolant to be used, and says it should be mixed 50/50 with distilled water. It ...
5
votes
3answers
1k views

How to do minor repairs to a radiator?

I have a radiator in my truck that has a slow leak which looks like it is oozing a little bit in between some of the fins. What are some of the ways to repair a radiator without replacing it? At ...
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
8k views

Bubbling sound from coolant and increase coolant liquid level

I drive an old Daihatsu Charade 1993. Just 2 days ago, I heard a bubbling sound from the coolant when I turned off the machine. I didn't really care much until yesterday when the car got hot ...
5
votes
3answers
106 views

What actually happens when there is not enough coolant in a car engine?

I know that a lack of engine oil can destroy an engine, so I was curious as to whether it is just as bad to drive a car with a very low engine coolant. What is engine coolant? What exactly are all ...
5
votes
5answers
15k views

What's making my coolant overflow?

I got home to find a trail of coolant down the driveway and puddles forming under the car (1991 Toyota MR2 - 5SFE). Concerned that I blew a hose, I checked them all. Nothing. Finally decided to see ...
5
votes
3answers
11k views

Air trapped inside radiator after adding coolant

It has now happened twice to me that after adding coolant to the radiator, when I turn the car on the RPM's will bounce up and down and the engine is reving (between 1k and 1.5k RPM's). Normal idle is ...
5
votes
1answer
72 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
3answers
1k views

Does a small amount of dried coolant warrant replacing block heater, radiator and hose Or can I use K-Seal?

My garage found a small amount of dried coolant on my radiator and block heater and tell me that I needed to replace my radiator, block heater, and hose urgently, as it could leak at any moment. I ...
5
votes
1answer
499 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
1answer
139 views

2003 Toyota Rav4 ECT Too Low for Readiness Monitor Drive Pattern

I recently failed an emissions test because my CAT and EVAP readiness monitors were "Not Ready" following a reset check engine light a few weeks back, which told me that the engine coolant wasn't ...
5
votes
1answer
29 views

How to flush coolant with only access to expansion tank?

OPEL CORSA B Sedan 1.6 IE 1999. I would like to flush the coolant and bleed my brakes. For the coolant, I have bought German HEPU antifreeze, Anyways, I only have a reservoir bottle and I do not ...
5
votes
3answers
4k views

Chronic ignition problems with 1996 Suburban, replacing distributor cap makes it go away

I'm trying to diagnose an ongoing ignition problem with a 1996 Chevy Suburban. Sometimes it won't start, and the previous owner said this happens regularly, and every time the problem occurred, ...
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
4answers
850 views

How can I fix my cracked radiator temporary for a trip? Is there any way to do it?

My car is a Chevrolet Lumina 2001. About 2 months ago I changed the radiator of my car because it was leaking, the guy that changed the radiator got the radiator in a junk yard place for cheap price. ...
4
votes
2answers
108 views

What is this (cooling-system related) part?

A while back I stopped my 2000 Ford Ranger (V6 4WD) and all of a sudden there was white smoke pouring out from under the hood, indicating that something was leaking radiator fluid. When I opened the ...
4
votes
4answers
27k views

My car has the wrong coolant in it. Now what?

Hello I realized today after beating my head about my car's overheating problems that I have the wrong coolant in it. About a year ago, my car ran dry. At the bottom of the expansion tank was an ...
4
votes
3answers
359 views

1996 Rav4 not warming up properly when driving and heat not hot

I have a weird problem. I recently changed the radiator and flushed the whole coolant system during replacing the radiator. I also flushed the heating core by itself. The thermostat was recently ...
4
votes
3answers
3k views

Coolant spills out of the overflow tank at high pressure

My '98 Subaru Forester spills all its coolant with very high pressure and overheats. I changed the radiator cap and did a flush, but still have the same problem. I added stop leak, but that did ...
4
votes
1answer
181 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
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
1answer
72 views

Is coolant testing necessary on modern vehicles?

My father in law continually reminds me to check my antifreeze when it starts getting cold. I get the squeeze tester out and it always shows everything is fine. We drive cars that are always less than ...
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
1answer
466 views

Coolant below minimum every 6 weeks - Mk4 VW Polo

This is about my VW Polo (mk4). It's been a cat C in the past after taking a knock to the front bumper. It needs the coolant topping up every six weeks (ish). I've been carrying a bottle of water in ...
4
votes
1answer
134 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
1answer
22 views

Coolant type for 1977 Diesel

I have a marine 1977 Perkins T6.354 6 cyl, 6 liter turbo diesel. There are different types of coolant available and I've done significant research into this question and have not found a clear ...
4
votes
1answer
1k views

Engine coolant gets to very low levels, but doesn't completely empty

2008 Toyota Tundra with a 5.7L V engine I noticed last month that my coolant reservoir was well below the 'low' mark. I filled her up, only to find out last week that it was back to the same spot ...
4
votes
2answers
25 views

1997 1.8t Audi Quattro - using coolant

I have an issue with my 97 1.8T Quattro using coolant. I've checked for external leaks and can't find any. The engine oil is still clean. Has anybody had this issue before? Is it possible for it ...