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.

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23
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8answers
150k 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 ...
18
votes
12answers
92k 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. ...
17
votes
6answers
1k 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 ...
15
votes
8answers
30k 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
votes
5answers
24k 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 ...
13
votes
5answers
172k 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 ...
13
votes
2answers
201 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 ...
11
votes
5answers
126k 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
votes
5answers
4k 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 ...
10
votes
2answers
81 views

Losing coolant fast after just fixing radiator

I have just got my coolant tank and radiator replaced after a leak in the radiator and a cracked coolant tank. I filled the coolant tank last month and now it is nearly empty. I am just wondering if ...
10
votes
1answer
147 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
134 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
3answers
341 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 ...
9
votes
3answers
2k 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
3answers
54k 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...
8
votes
3answers
4k 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
2answers
4k 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 ...
8
votes
4answers
34k 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 ...
8
votes
1answer
806 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
185 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 ...
7
votes
4answers
156k 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
2k 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 ...
7
votes
2answers
49 views

How to flush engine coolant system after oil intrusion

My 02 Buick LeSabre has oil coming from the radiator into the coolant reservoir. Just recently I had a new motor put in to fix the issue. What would be the best/proper way to flush the radiator? It ...
7
votes
1answer
139 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
181 views

Coolant pouring out from under 1998 GMC Yukon as fast as i put in

I filled my radiator with water and it is pouring right back out of the rear of engine as fast as i fill. It seems to be near or behind the transmission. https://youtu.be/27qV-ufMsQc How can I find ...
6
votes
2answers
28k 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 50-...
6
votes
2answers
155 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 ...
6
votes
3answers
17k 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 ...
6
votes
6answers
26k 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 ...
6
votes
1answer
91 views

Why do modern vehicles omit a temperature gauge?

I'm more specifically interested in performance vehicles. My current car has gauges for coolant temperature, oil temperature and oil pressure. The coolant temperature gauge is there so you can tell ...
6
votes
2answers
76 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 ...
6
votes
3answers
6k 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
3answers
3k 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
66 views

Will an engine overheat if it has no coolant recovery tank?

My wife's Mini has a leak in the coolant recovery tank, and she has been told by the dealer that her car is at risk of overheating without the coolant recovery tank.Frankly, I don't believe it. Cars ...
5
votes
2answers
116 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
483 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
4answers
15k 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
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
128 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
295 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
9k 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
1answer
82 views

I have engine oil in my coolant. What might be the reason?

I have purchased a pre-owned car. After the purchase I saw there was engine oil in the coolant reservoir and also the coolant level is going down slightly. Engine is not heating up. What do I do? ...
5
votes
1answer
97 views

Min/max fill for coolant reserve/overflow tank in abscence of markings

I have a 2001 Honda Prelude SH. I am looking at the coolant reserve tank. There are no min / max fill lines visible, although the manual says there should be. I am just re-adding coolant after fixing ...
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
98 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
1answer
3k 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
37 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 ...
5
votes
1answer
192 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
2k views

Is it necessary to run the engine after adding radiator coolant or only when draining?

I recently did a timing belt/water pump change on my own. When I changed the water pump i drained the coolant, and according to my mechanic, I blew my radiator by not running the engine with the cap ...
5
votes
2answers
609 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 ...