A water-based fluid used to remove heat from the engine. Also see cooling-system for related components such as the radiator and water-pump.

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13
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7answers
70k 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 ...
13
votes
8answers
17k 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 ...
10
votes
8answers
61k 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. ...
10
votes
5answers
16k 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 ...
9
votes
5answers
2k 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
4answers
95k 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 ...
8
votes
5answers
77k 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 ...
7
votes
4answers
90k 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
1answer
526 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 ...
6
votes
2answers
2k 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 ...
5
votes
3answers
815 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
23k 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...
5
votes
2answers
16k 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 ...
5
votes
3answers
843 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
274 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
5k 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
6k 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
765 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
78 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
2answers
2k 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
1k 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 ...
4
votes
2answers
68 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
18k 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
1answer
107 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
413 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
4answers
9k 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
951 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
1answer
913 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 ...
3
votes
2answers
2k views

accidentally placed oil in the coolant reservoir in a BMW 325i. How do I fix it and what is the cost?

I accidentally added oil to my coolant reservoir. I have a BMW 325i. The oil light came on and I figured my oil may be low. When the oil was added the oil light warning went off. However, the ...
3
votes
4answers
3k 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 ...
3
votes
1answer
94 views

In Columbus, Ohio. 28 degrees out for last 9 hrs. Only water in radiator.Can I start and drive safely?

99 Ford Windstar. I kept water in all summer or else it ran hot. Been trying to get antifreeze in through the top because I had no money to pay to find and fix problem, now since cooler outside, water ...
3
votes
2answers
7k views

My car won't start. Is it that I ran it without coolant or is it my battery?

Sunday I didn't use my car. At 9pm I moved it across the street because the street sweeper was passing on Monday. Monday morning at 8:30am my car doesn't start. I remembered that I haven't checked ...
3
votes
2answers
2k views

Mixing antifreeze?

My dealer has not been good about topping off fluids lately. I bought some antifreeze (http://amzn.com/B0089LSFJ0) to get the level to just above minimum, but I'm concerned that I don't know what the ...
3
votes
1answer
7k 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 ...
3
votes
1answer
1k views

1994 Ford Escort won't start

I have a 1994 Ford Escort that was bought used 2 years ago. When we bought it, it would barely run, and we had to replace the engine head. As a result of that and other repairs, it has been losing ...
3
votes
1answer
180 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 ...
3
votes
3answers
1k 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 ...
3
votes
1answer
42 views

1994 LT1 350 in a Caprice wagon. Oil getting pumped into the coolant and flowing past the coolant reservoir cap

The engine runs well and the transmission shifts well. The only indication was the oil gauge dropping at a stop light. I immediately put 3 quarts in. There was nothing visible at this time. When I ...
3
votes
1answer
28 views

radiator stop leak

I woke to find antifreeze all over the driveway. My reservoir was empty. I took it to the radiator shop and they said I had to leaks. Then I remembered I had the warranty so I took it to the ...
3
votes
1answer
851 views

Mechanic Troubles And A Small Watery Oil Leak

My car is a 2005 BMW 525i E60 with about 180,000km on the clock. It has been well looked after and serviced. I don't get dealer services, but go to a mechanic who has always been good and uses the ...
3
votes
1answer
53 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 ...
3
votes
1answer
317 views

1995 Chevy s-10 4 cylinder running hot but not overheating

I am having an issue with my s-10. It runs hot but is not overheating. It started when I replaced the temperature sending unit and thermostat. I put in an additional thermostat to make sure the first ...
2
votes
2answers
672 views

Why did GM change the pressure rating of their coolant tank cap for existing vehicles?

GM has changed the part number for the radiator surge tank cap on vehicles that came from the factory with Dex-Cool. The new cap is 18 PSI (RC87 - part number 25713160), the old one for many vehicles ...
2
votes
3answers
874 views

Clear water in coolant reservoir

Over the weekend I took my 2000 Toyota 4Runner to a local shop to get the oil changed. While there they told me I needed to flush the coolant, pulling clear water out of the coolant reservoir. They ...
2
votes
2answers
22k views

Using only coolant or mix of water for radiator?

Do I have to use only coolant for radiator or mix coolant with water, if so what percentage of coolant and water should be mixed?
2
votes
2answers
58 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?
2
votes
2answers
6k views

How long does coolant last in storage?

I recently needed to top-off the coolant on my car, but only used a part of the gallon-sized 100% antifreeze container that it came in - how long is it worth keeping the rest in my garage for future ...
2
votes
2answers
428 views

Can I use an intercooler as a charge cooler radiator

I'm looking at creating an advanced charger cooler setup for my car, can I use an intercooler as a charge cooler radiator? Or do radiators need some special coating on the inside of them? It's a ...
2
votes
1answer
29 views

95 Corolla overheats, probable coolant leak or maybe thermostat, need more advice.

Vehicle is a '95 Toyota Corolla. Was driving yesterday for about 5 minutes and glanced at the temperature gauge which I noticed was running pretty high (weather has been around 90 degrees f ...
2
votes
1answer
23 views

How to test for radiator leaks?

There is coolant leaking from my 2007 Tacoma's radiator SOMEWHERE because there is leakage dripping from the lower right corner. I saw it when I took the skid plate off to replace the serpentine ...