Me and my girl took her 05 ex 1800 miles from the SF bay area to arizona and back and the car was pushing coolant out the overflow/catch can. The cars temp would remain fine at freeway speeds, but as soon as speed dropped the temp would rise, and I would have to stop and put about a 1/2 gallon of water in it. Took it to a shop, and they did a block test, as well as other things and determined that it was a block in the radiator. replaced the radiator/cap/hoses/thermostat, and all gaskets.... Still has the same issue. Around town its fine but still looses coolant at a VERY slow rate and how I noticed it was the heater stopped working about every 6-7months. Theres no signs its the head gasket(no smoke/sweet smell from exhaust, no traces in the coolant or oil either). The water pump seems to be fine as it flows water when its full and when its getting low bringing up the revs will bring the temp back down. The car has 84k on the clock and has never had a issue or overheated before. Highest temp its seen is about 3/4 to 7/8 up the gauge.

 

You have an over heated motor. "Blown" head gasket and/or a warped head. Exhaust gases are being crammed (through the warped head/blown gasket) into your cooling system, forcing the coolant to overflow out of your resevoir. This is the most likely reason.

 

Check your Engine Coolant Temp sensor and Fan Relay. If you run the engine and it begins to overheat and the fan does not engage, but you can hit the A/C button and both fans come on, then this is your problem. Blown head gasket will usually cause a rapid overheat even in idle. Fill your cooling system and look for bubbles in the coolant reservoir. The fact that you can drive at highway speeds without over heating tells me that you have coolant in your radiator, its able to circulate, and that its the motion of air thru the rad that is cooling, aka fan does not engage when you come to slower speed. I would strongly suspect the fan relay or 'switch' (ECT sensor).

 

^^ Slim, but possible I guess. However, the symptoms he's describing fit rather well with those of people who have had a blown head gasket.

 

fans work fine and car can idle all day and drive around tow with zer issues.. only reason why it will heat up is cause there isnt enough water in the system.

 

There are two reasons your coolant would be disappearing.

1. As you have described, it's being pushed out of the reservoir. Typical symptom of a blown head gasket.

2. It's being drawn into the cylinders and vaporized. Although it may not be enough to cause your exhaust to "smoke" .. it could very-well be happening. Again this would be caused by a blown head gasket. (or cracked head, if you're really unlucky)


Based on your descriptions of the symptoms that you're experiencing, I'm leaning towards a blown head gasket.

 

Ya my suggestion was banking on the coolant loss arising from overflowing the reservoir. Pretty odd tho, the only car i've ever had with a blown head gasket went from perfectly fine one day... to no coolant, terrible idle, over heat and seized within like 50 km's. Once the gasket went it was a quick destructive down hill from there.

 

how do i test for it then? Already had a block and coolant test done that came up fine.

 

Go get yourself a compression gauge and run a compression test. Instructions should come in the box with gauge. You are looking for low compression numbers, typically you will see consistency in all cylinders except one, the one with the gasket breach. You can also use a vacuum gauge (not my preference, see google for details on use) or do a "leak-down" where compressed air in added to each cylinder (usually more accurate in diagnosing valve problems). Compression test is you best bet for an absolute affirmative DIY diagnosis.

 

actually, have a leak down test done AND get your coolant tested to see if there is any monoxide in it. you might also be able to tell if it has exhaust fumes in it being that (in my experience with these issues) it will me a darker flourescent green as opposed to the flourescent greenish-yellow color.

 

It's your headgasket. Ask me how I know...

By the way, I believe there was a recall for blocked radiators in that model year. You might be able to get reimbursed for that.

 

A quick and easy test is to; remove radiator cap, fill to the top with coolant, and rev the engine a little to see if there are bubbles. Which would indicated cylinder pressure entering the cooling system.

If you get bubbles, you can get one of these devices to see if they are indeed bubbles from combustion.

http://www.autozone.com/autozone/acc...er=391378_0_0_

Good luck. I just went through the same thing.

 

Compression and monoxide tests came back fine, as well as no bubbles.

I commute about 10 miles to work and the car hasn't lost a drop of water in the last few days. Only thing different from when we were on our trip is that I'm only traveling at 50-60mph compared to 75-85mph for extended periods... And I also removed the overflow cap as well... This is getting rather frustrating.

 

getting the are out with that isn't a bad idea if you knew that the air wouldn't go back in. its like using a household water hose to put out a forest fire... the effort is only valid you're 100% sure the air wont re-enter the system.


>if i were you, i would take the head off and see if it is warped... sounds like that's all you have left to do, my friend... big job, sort of... but it might give you answers..

 

I'm not sure why you mean. You just put the tool above the rad opening, and draw air through it. If it has carbon dioxide in it, it changes from blue to yellow/green.

I tested it in the open air, and it stayed blue. I also did it just by breathing into it, and it changed to yellow/green.

 

Have you replaced the rad cap yet? 94

 

 

I had a similar problem...and after changing my rad/cap/hose/therm and head gasket...it ended up being my water pump...lol waste of labour and money

 

Back from the dead.... I know.
But any solution to this?

 

Yeah, I'm now having pretty much the exact same problem.

Two days before i had my timing belt/water pump changed I started having this problem. We thought it was the radiator cap, so I changed it too. Went on vacation for a week, no problems, but never drove over about 55. Now it's happening every day on my drive to and from work, 49 miles, mostly interstate, mostly 78mph. It literally dumps nearly all my coolant into the reservoir with enough force to blow it out of the tightened cap. There's no negative pressure in the system, I opened it hot and air blew out.

The local mechanic (next to my office) did a sniffer test, negative, pressure test to 25psi, good, rode it about 6 miles up the road and back at 80mph, no problem. Puts another radiator cap on it, gets the reservoir fluid to the right level, fills the coolant system, and off I go, 49 miles home. I get home, coolant coming out the reservoir cap, overheating when stopped.

I don't think it's the water pump. It was changed after the problem started, and no change. Thermostat is about a month old.

My uncle, who's also a mechanic, phone diagnosed this as a head gasket, but the local mechanic is almost adamant it's not, though he doesn't know what it is. It's like he doesn't believe that because there's no coolant in the head/on the plugs/in the oil/etc, the sniffer test was inconclusive (not the gas analyzer), and the pressure test on the coolant system was good, that the head gasket could be bad.

Could the gasket be worn and acting like a 1-way valve, pushing air through the gasket only when running high rpm, lots of pressure, and during the exhaust stroke, the negative pressure pulls everything tight and seals it up again?

 

It's the head gasket. don't waste anymore time trying to figure it out or do tests. For some reason this motor won't show the typical signs of a blown head gasket.

Have the head gasket replaced, check the head to ensure it's not warped or cracked and call it done.