Engine overheating, radiator fluid keeps dropping, no leaks on ground

[moocow]

So I was driving my 99' Camry 4cyl (126,000 miles) to work in the morning, on a cold start, it started fine, no white smoke out of the back. However the temp gauge goes over the top after a minute or so, also the check engine light turned on. I have noticed that over the past couple of months the radiator fluid needs to be added all the time. I don't see any leaks on the ground, and some people told me that I may need a new head gasket. I feel no power loss to the engine either. Also changed the radiator out back at 90k miles so a crack may be unlikely but still possible. Any other input? What common problems does the 5sfe engine have at this many miles?

[renmike]

Your easiest indicator of a blown head gasket would be to check to see if your oil has a milky look to it. If you're losing coolant but it's not leaking to where you can notice it, there's a chance that it's seeping through the blown head gasket and mixing with the oil.

[moocow]

I gotcha. I've asked a few people around to see what they say and they also mention blown head gasket. I'll have to check w/ the car later today to see whats up with the oil colors. If it is a blown head gasket, is this easy to replace? DIY over the weekend or just take it to a shop? I replaced the engine starter last week myself, it was easy but I'm not sure whether or not to take the next step into the engine. I heard you need to take out a lot of stuff, the belts at least and a lot of other things involved, which is probably an understatement.

[renmike]

Unless you're proficient and have done work such a head gasket, then it could be a weekend job. If not and you're up to the challenge, then make sure you have a backup vehicle, because things such as setting the timing and torquing down the head bolts correctly come into play.

In most cases, I would recommend taking it to a good shop and having them do the work, then you have it warrantied and they can check the head and block for any warpage which would indicate other things that might need to be done.

[Preacher1]

I don't know what all you've looked at and tried, but please get a new radiator cap and watch it a couple of days before doing anything drastic. I had a matrix which did the same thing and the mech's couldn't find anything wrong. Finally I got a new cap - problem solved several hundred $$ later

[ShawnM]

Before digging into the head gasket make sure the coolant isnt leaking out anywhere else. If its a small enough leak it will cook off on the engine block before it drips onto the floor. I would also scan the computer to get the trouble code before disconnecting anything. It coulb be a catalysit effiency or oxygen sensor code if coolant is getting into the combustion chamber.

[dc_98_cam]

Most shops and mechanics have a test tool called a coolant pressure gage tester. You attach it to the radiator fill neck, pressurize it to the appropriate level, and watch the needle for so many minutes. If the leak is external, you can probably see where it is located. If it is internal, such as within the engine block and headgasket, you won't be able to directly see the leak, but you should realize that something is wrong.

[Eye8Pussies]

also check the fins on your radiator for crystalized coolant- you can lose coolant through your rad fins from small leaks that will never reach the ground

[moocow]

Thanks for the input guys. I've talked to several people today while at work to answer some questions. I'll also have to add that the engine does not idle well on a cold start. Sometimes I have to hold the gas pedal down a bit to hold it at 1800rpm's to idle. Then after a couple minutes it will hold its own. I have also downloaded a .pdf for servicing the engine, and other manuals of interest. But of course before I go on any further I will check other things before getting to the head gasket. Yes I have a backup vehicle

[toyomoho]

Did you ever find the reason the engine overheated?

One other test is a coolant test for exhausts gases, a radiator or auto shop should be able to do this or you can buy a kit at an auto parts stores. Pull the plugs and look for one or two that may have a much lighter color electrode (white) and appear to be very clean compared to the other.

As suggest by TN posters before digging into the engine use a very strong shop light (and you fingers) to check for coolant or signs of a leak (evaporated coolant dye). This includes radiator core plus top and bottom, on top of the plastic air skirt that is at the bottom of the radiator, coolant overflow tank, heater control valve (you should be able see and feel this unit for coolant), all heater hoses including bypass hoses and top of transmission where leaking coolant my accumulate. Also feel the carpet under the heater core for moisture.

Have had pinhole leaks on radiators (even a new one) resulting in no liquid being present when checking due to evaporation plus hoses with very minor leaks that could only be found by feeling for coolant. Use your nose; often you can smell coolant evaporating on a hot engine or coolant system.

If you do go the head gasket route as suggested by TN posters plan on a long weekend if this the first time. Make sure you have access to all tools required. Might think about having the head pressure tested, perhaps a valve job or new valve stem seals. These can and do wear out as the miles add up and are much easier to replace with the head off.

Cold start issues could be something else such as cold start injector, IAC valve, etc.

[-=]KaiN[=-]

your coolant doesn't have to leak into the oil it could be leaking into one of the cylinders, pull all the spark plugs and look down the holes with a boroscope. If you find a piston that is clean and shiny thats the cylinder the head gasket has blown into. The coolant leaks into the cylinder steam cleans the top of the piston then is burnt in the combustion chamber and shot out the exhaust. Sounds to me like that is the case here.

[Xzbit702]

Moocow I had the same trouble as you take a look at my thread http://www.toyotanation.com/forum/t207212.html .I would go to a shop have them test it to see if you do have a blown head gasket they will tell in like 5 minutes.If you want you can replace the thermastats and also check you hoses.My expirence with the head the last 2 weeks have been tuff.Im pretty good with cars but this was definently the hardest thing i have done to my car.The problem is if you do have a blown gasket you might have your heads cracked so you might have to get them welded and stuff like that.THen again it could just be the gasket.ALso you would have to calibrate them correctetly to make sure everythin is running smooth.Its alot of work but it can be done if you have knowledge about cars.If you do get into this project i would highly recomend you have a back up car or at least secure your rides to school or work or whatever you never know what little glitches you might come across but be ready.Ill post some pics up soon.

[Xzbit702]

I just put some pics up too so you can get an idea of all the mess.

[moocow]

Got the engine check light code P0115 for Cooling temp sensor...

I drained the oil too. Its looking pretty dark, but nothing "milky" like how I was supposed to find if the coolant was mixing in it. So what now?

[tonycc]

I hate to ask such an obvious question, but I didn't see you mention it yet.

Have you checked/replaced the thermostat? If so, did you place it in the correct orientation?