Overheating Issues - Toyota Nation Forum : Toyota Car and Truck Forums

haux · 07-16-2009, 12:11 AM

Ok, so over the past few years I've posted various questions regarding my cars' overheating issues. I thought I had fixed all of the problems. I guess not...

My 2000 Camry is currently at just under 325,000 miles. In 2005 the radiator fans died and caused it to overheat. For several months after, I drove the car as-is with the a/c heat on max. I'm sure that caused some damage to something. Eventually I replaced the motors. I had also replaced the thermostat, on a couple of different occasions in fact. Last year I started experiencing random overheating that caused the coolant to boil into the reservoir tank. That was probably the engine spitting the coolant back out. I thought there was an issue with the water pump not circulating the coolant well, so I replaced it.

Everything seemed to be ok until recently, I started experiencing the same problems. Under stress, the coolant is being dumped back into the reservoir tank at boiling temperatures. Every other day I add water to the tank to make sure it never gets low.

Just tonight, it got worse. I noticed smoke/steam coming from under the hood. The temp gauge was at max. After some investigation I found that the radiator was bone dry. I refilled it and the reservoir tank, and everything is ok... for now.

What could be going on? Sometime within the last year and a half I've also replaced the coolant temp sensor and the engine temp sensor.

With all of this stuff being new, I can't figure out what else could be causing it. Any ideas would be greatly appreciated.

Mike Gerber · 07-16-2009, 07:49 AM

Sorry for the obvious answer, but refill the cooling system and drive the car until it's good and hot. Then lift the hood and try to see where the steam is coming from. It could be as simple as a cracked coolant hose. It could also be a cracked radiator or it could be a blown head gasket due to all the constant overheating the car has been subjected to. You are the best detective for this issue since there is now steam coming from the engine. You need to visually check the source of the steam.

Mike

haux · 07-16-2009, 02:27 PM

Quote:

Originally Posted by Mike Gerber

Sorry for the obvious answer, but refill the cooling system and drive the car until it's good and hot. Then lift the hood and try to see where the steam is coming from. It could be as simple as a cracked coolant hose. It could also be a cracked radiator or it could be a blown head gasket due to all the constant overheating the car has been subjected to. You are the best detective for this issue since there is now steam coming from the engine. You need to visually check the source of the steam.

Mike

Steam isn't constantly coming out. I know where it was coming from. The engine backed up all of the coolant into the reservoir and it overflowed. What I need to figure out is why it's doing that. What is causing the engine to overheat in the first place that it has to do that.

I also forgot to mention... the radiator was replaced in 2007. And when I got an oil change a couple of months ago, the guy at Pep Boy's said there was an oil leak in the head gasket and valve cover. But, I don't see how either of those can cause the engine to overheat. I always monitor the oil level, so it's not that either.

A few weeks ago I drove up to Mount Washington. I'm not sure if you're familiar with it... but the road is eight miles of steep driving. It was a pretty good test of my engine. After driving for a bit running the engine nice and hard, I'd stop to let it rest. Shortly after stopping, coolant would back up into the reservoir and it would be boiling. Then as the engine cooled, I believe it would suck it back up.

Is that normal? If not, I think that's what the problem is. The coolant is *not* leaking out. Something is causing the engine to overheat... which causes it to spit coolant back into the tank, often overflowing it.

Mike Gerber · 07-16-2009, 02:50 PM

"And when I got an oil change a couple of months ago, the guy at Pep Boy's said there was an oil leak in the head gasket and valve cover."

If oil is leaking out of the head gasket, chances are coolant is also leaking in and out too and from one cylinder into another. There are several cheap and easy things you can do here yourself. The first is to simply get a new radiator cap for a few dollars. There are many cases of the cap no longer holding the proper pressure and causing overheating, so eliminate that first and cross your fingers. The next step would be a simple test for a blown head gasket. You would need to go to any auto parts store and ask for a kit to check for a blown head gasket and how to use it. They should be able to explain how to use it. The kit should run about $25. If it determines you have a bad head gasket then report back here and well will discuss your options. I'm leaning toward a blown head gasket here since you said "For several months after, I drove the car as-is with the a/c heat on max. I'm sure that caused some damage to something." and the radiator and thermostat have already been replaced and you don't see any obvious external leaks. Do these tests first to varify.

Mike

haux · 07-16-2009, 02:56 PM

Thank you. I will do that.

haux · 07-16-2009, 10:53 PM

And the verdict is... radiator cap.

I replaced it, started the car, and immediately noticed pressure in the two big left and right hoses. Previously, I could squeeze both of those hoses easily. Now they're nice and stiff and it takes some effort to squeeze them. Looks like I may not have even needed to replace the water pump before.

I asked about the head gasket kit at Pep Boy's and only one guy knew anything about it, but they didn't have it. However, I will still look into that.

Thank you for your help.

RandySolara · 07-17-2009, 01:12 AM

haux did u get ur issue fix ? lol drove u crazy eh

u suprised it was the radiator cap hahah, Toyota is sensitive, if the gas cap and air intake losen or improperly close, u get CHECK ENGINE too

haux · 07-17-2009, 01:25 AM

Yes, I replaced the cap today and noticed immediate improvement.

Occasionally, the check engine light comes on for some emission codes. So when it came on recently, I didn't bother getting it checked yet. So there may very well be a new code regarding the cap. However, now that I think about it, the cooling system pressure has been poor for a long time. Those tubes have been very easy so squeeze until now, with the new cap. So that tells me that the pressure has been bad for a while.

RandySolara · 07-17-2009, 08:56 AM

Camry hardly get CEL emission codes since ur car is year 2000 with well care except this

i still have my oldie Camry 1994 i scan for the code everytimes if i get CEL, its not good to drive with check engine light on. I get CEL for Gas Cap before.

Mike Gerber · 07-17-2009, 09:02 AM

Glad it was only the radiator cap. You just saved a lot of money.

lf you have Autozone in your area they will read the codes for you for free. Just go in and ask. Get the code numbers. Don't just let them tell you what they think is wrong. There job is to sell you parts, right or wrong. They will try and do that. Post the codes back here and someone will be able to give you some direction.

Mike

haux · 07-17-2009, 11:58 AM

I've done it before. The codes were: P0401 P0440 P0441 P0446 P0770, and then "P0440 P0441 P0446" repeated again at the end. I think the P0770 was a fluke or something.

And I've already gotten some instruction before on what to look into. I remember that it was going to take a bit of work, so I never got around to it. Hopefully this time when I get back home from my work trip I will do it.

I will definitely have the codes checked again to make sure nothing new has come up.

(By the way, I don't think it is the gas cap, because I still hear the release of pressure when I untwist it. And, my exhaust can smell a bit funky, so it probably has something slightly more.)