Nyhm

Hello guys/gals, brand new to this forum and hoping to find an answer to my problem because it is seriously starting to irritate me a lot. Occasionally when I take drives that last about an hour or so my coolant in the tank will literally overflow out of the cap which is tightened securely causing a pool of antifreeze to form under my car. I replaced the thermostat about a month ago thinking that might be the problem but it happened to me again yesterday afternoon. Some people have told me I have a blown head gasket but there is no sign of that and the engine runs fine and never overheats. I'm trying to solve this as soon as I can mainly because of the pets in my neighborhood, I don't want any of them to drink this under my car and die. Any advice?

JimC

A blown head gasket will cause exactly what you describe. It was the only sign I had of the problem. The car never overheated according to the gauge, but would blow coolant out of the cap.

It was under warranty (so a long time ago) - and since Ford was paying for the replacement I'm sure that is what the problem was. Never came back after they replaced the head gasket and I now have 202,500 on the car.

Nyhm

I thought you could hear something extremely coming from the engine plus it doesn't do it every time. If that is the case do you have a rough cost and getting it replaced?

JimC

When mine went there was no sound or anything. Just the coolant blowing out of the reservoir.

Can't help you on a price. Mine went while the car was under warranty so I never really saw the bill.

If you can get a look from underneath though you might see some coolant leaking down one of the heads. When it happened on a friends car we had his on a lift, looked up and noticed the coolant at the back of the head on the passenger side. That was the first clue he had an issue. He fixed it himself though so again, can't help you with a cost.

Nyhm

So I guess my next question what would've caused it? I don't run it super hard or anything. I was also told that if the head gasket was blown your oil would be contaminated with antifreeze or vise versa

bigblue95z

Most of the time you will see oil in coolant or coolant in the oil, but that's not every time.

You should start with a cold start and let the engine get fully up to temp. Then check both sides (before and after the water pump) to be sure it is pushing coolant around. Could be a bad water pump. You can use an infered temp gun to find out. If it drops more than about 10*, you prob have a bad water pump. That way you can rule it out.

Nyhm

Have you seen a bad water pump cause this problem before? I just find it weird because it doesn't happen every time and the temperature gauge is never goes above the normal (middle) and it boils out of the cap, nowhere else.

Art161

I don't think the stock water temperature gauge is particularly accurate. Mine works its way from full cold to the center of the scale and doesn't go any higher--cold weather on the highway or hot weather in the city makes no difference in the position of the needle. Somehow, I don't think the temperature is really staying the same; it's just that the gauge doesn't show the temperature increase. It makes most drivers happy to see the needle point straight up all the time while driving. The gauge acts pretty much as an "idiot light" from the center on up. By the time the needle would move up, you'd be boiling over big time, not just a little.

bigblue95z

Yes. You have to think about where the temp sensor is compared to the coolant flow. (and not all cars use the same sensor for the gauge and ECM) It can be boiling in the block pushing coolant/air back to the resevoir, but since the coolant isn't flowing, there is an unequal distribution of coolant temp. Your hot water never feels hot as soon as you turn it on, right? Even though at the other end, it is scalding hot. And I wouldn't put much stock in the OEM temp gauge. Your oil pressure fluctuates all the time with throttle, but do you ever see the gauge move? Get your car up to temp and when it starts to happen, kill it and check the temps throughout the coolant paths you can get to with a temp gun. They shouldn't change more than about 10 degrees. If they do, you have a coolant flow problem. Whether it's a clogged radiator, bad water pump, etc.

Nyhm

Maybe I should go get the radiator flushed to see if that will fix my problem for cheaper huh? I'm a college kid so im fairly broke haha, here's a picture of my car too, gotta get the stripes re-done though