Toyota Camry Cooling System Questions

greenmouse

I have a 2003 Camry that has recently begun having issues. While driving or idle, the RPM's start going up and the temp guage immediately goes down to past the Cool. If I put it in Neutral the RPM's go higher and my engine is revving. If I were to take my foot off the brake, the car would go by itself. Eventually, the temp guage goes back to normal and my RPM's subside. However, if the car is in Park and this happens and I try to put it in drive, then I'm unable to start my car for about 15-30 minutes. I've taken it to the mechanic twice, and both times, they claim to "fix it." Can someone PLEASE help me? thanks.

kiawah

When they claim they 'fixed it', what did they do and what parts did they use?

Is there water/antifreeze in the radiator and overflow tank to the right levels? Are you having to add water to keep the levels correct?

greenmouse

They got rid of some corrosion on the battery connecters and replaced the water pump. They said that the water pump was cracked and that was causing the temp. issues and the battery corrosion was the cause of my car not starting occassionally.

kiawah

So when the waterpump was cracked, did it leak all the cooling fluid out, resulting in your car overheating and stalling?

greenmouse

no, it leaked some not all, but it never overheated or stalled because of it.

kiawah

The symptoms sounded like either a bad waterpump, air in your cooling system, a defective thermostat, and/or a defective temperature sensor.

They've swapped out your waterpump, so you should have good coolant flow (assuming it isn't air locked, and the thermostat is opening at temperature).

If the car overheated and stalled out I would be very concerned about a blown headgasket....but I'm still slightly concerned about that ultimate possibility depending upon what else you find in trouble shooting this. You could see loss of coolant without seeing leaks, oilish film in the radiator, and or a lot of air that continually enters the coolant system.

If you had a simple air blockage (due to replacing the waterpump and refilling), those air bubbles should clear themselves after a number of heatup and cooldown cycles. As the engine heated up, the thermostat would open, air bubbles in the system would get flushed up the highest point in the radiator, and as the radiator cooled down it would draw in replacement coolant from the reservoir. After a couple of cycles, during heat up the air gets flushed out to the reservoir, and replacement coolant is sucked back in during cooling. Be sure to turn the heater on at least once so that the coolant flows thru the heater core clearing that line or air as well.

If the thermostat was stuck open, then the vehicle would come up to temperature slower. If the thermostat was stuck closed, then the vehicle would overheat. If it was sporadically sticking, then you'd see flukey symptoms.

The temperature sensor would feed the gauge, but also is an input to the engine computer which can adjust the fuel mixture, timings, rpm, etc. So a bad sensor can affect the smooth running of the engine.

So I'd personally be watching closely the air and coolant levels in the radiator and reservoir for a couple of heating/cooling cycles. Assuming you don't see air entering the coolant system from the cylinders, an oily and/or foamy substance, or loss of coolant ......then I'd replace the thermostat (cheap to do), and focus on the temperature sensor after that.

greenmouse

Thank you so much! I will replace the thermostat and then check out the sensor.

alh2

I was driving in the foothills at about 80 mph and looked at my temp gauge and it had gone past the hot. I pulled over and had no steam and could hold my hand on the radiator cap. The radiator was full. I let it cool down and drove 60 miles home with no problem. What do you think could of been the cause. Could the transmission fluid have gotten that hot and could of showed up on my temp gauge?

kiawah

Possibly the thermostat was stuck closed. Also could have been air locked, but that doesn't make a whole lot of sense on a 2006 which I'm assuming has had nothing done to the coolant since new. Have you had anything done, or any leaks? Have you had to add coolant since you got the car?

When you say it was 'full', what was full? The radiator overflow tank? or you opened the cap to look in the radiator and the radiator was full?

Assuming original coolant with nothing done to it, and it is still full......depending on your circumstances and how critical the availability of the car is, you can just watch it for a while to see if you have a problem again, or you could just swap out the thermostat since they are cheap.

I'd at a minimum make sure that the radiator is indeed full, and in a pinch if you overheat again you can run the inside heater full hot blast to help cool whatever coolant is in the engine.

alh2

My overflow was full and the radiator was full. I ran the heater and it didn't cool down, also when I checked it the electric radiator fans only turned on for about 20 seconds and then turned off, even though the gauge said over hot. If the thermstat stuck would it allow it to be cool enough to not steam and not spit out fluid?

igr

I've bought 2004 Camry LE 4 Cyl. 7 months ago and has been driving it since. Coolant level in overflow tank was stable when I have been checking it for the first couple months. Then I stopped paying attention, but recently noticed that my overflow tank coolant level is below LOW mark. I can see coolant when I open radiator cap with the engine cold. Is it normal for this car to loose certain amount of coolant or I should start looking for the leak? :confuse: Parking space is dry, but again, leak might be tiny, because, I don't see rapid decrease in the coolant level in the overflow tank.
I bought concentrated long-life coolant from the Toyota dealership just to top off the coolant and now not sure which water I should use to dilute coolant: distilled or tap water will do. If anybody has such experience, I would appreciate to hear your opinion.

210delray

I have 2 Camrys, an '04 and an '05. Both are 4-cylinders and both use a little coolant over time. I just top up every so often (once a year or so). Use distilled water with the concentrated coolant (50-50 mixture).

igr

Thank you, 210delray. I don't have distilled water, so I'll top with concentrate for now and watch the level for a month. I'll post my findings, if any.

matt15

210 delray, how much coolant do you need to add yearly? I have a 2005 and 2007 Camry, both 4 cylinder, and on both I need to add almost the full overflow tank once a year. I had the dealer do a pressure test on the 2005 and found no leaks and I also had an oil analysis done with no coolant in the oil. I'm at a loss as to why the coolant level goes down with no signs of a leak. Is it evaporation?

210delray

I add much less than that; the level may drop only slightly below the "cold fill" line. But my Camrys only go about 8000 miles per year, so that could be part of the reason. Also, do you live in a very hot climate (like Phoenix or Las Vegas)?

I doubt evaporation would occur, as the system is closed. I'd recommend checking the level when the engine is cold, such as first thing in the morning.

igr

I've topped my overflow tank well above FULL mark on Nov 21, 07 and now 2 months later coolant level is below LOW mark again. I still don't see any obvious signs of leaks. :confuse: I'm in Toronto, Canada, so no high temperatures here this time of year.

matt15

I'm in Maryland, so not the heat all year like in Phoenix. I do check the coolant when the engine is cold. The 2005 is driven more, around 9000 per year. The coolant level will get close to the low mark on the overflow tank and that is when I refill to the full mark.

I check the level weekly. The '07 has dropped about to just above midway on the overflow tank and the car has 7,800 miles, purchased in April 2006, so this car is less used and the coolant loss from the tank is less than the '05. I'm beginning to believe this is just normal for these vehicles as the coolant loss is not dramatic and happens over an extended period of time.

igr

I've been driving with an empty overflow tank for a week now (I have ready coolant in my trunk just in case). Every morning when engine is cold, I check under the radiator cap and see that coolant is there, engine doesn't overheat during driving, so radiator seems not to be leaking. There are no leaks under the overflow tank either. So, it seems, that I'm loosing full overflow tank in 2 months due to evaporation only :confuse: :confuse:
I've checked the cap of the overflow tank for resin insert and it looks good to me (no crack, no deformations).

igr

I finally found signs of a coolant leak, besides slow level drop in the overflow coolant tank. Lot's of pink crystals in the area of a water pump, on the left side of engine, right under the belt. After visual inspection at Toyota dealership, service adviser told me that water pump has to be replaced. But when mechanic got to the the leak, it was found that some plastic plug on the left side of the engine block was leaking and not the water pump. Adviser told me that plastic plug can't be ordered as a part(not supplied by Toyota) and he has to order the "short block" assembly. I asked for more details and it appears that the whole engine block has to be ordered and replaced, because of the leaking plastic plug :confuse: :confuse:
It's hard to believe, but I can't blame dealership for blowing repair volume, because warranty covers all the costs. Apparently, that plastic plug was so reliable leakwise, that there was never a need to supply it as a part, therefore the only way to get it is together with the engine block.
I'm worried about such significant change. I asked adviser if I have to go through break-in period, because of new engine block and he said, that engine doesn't need break-in even if new, transmission does. Sounds weird to me :confuse: :confuse:
Anybody went through engine block replacement?

210delray

I've never had an engine replaced, but you will have to repeat the break-in process with the new engine per your owner's manual.

igr

Engine short block has been replaced sometime at the end of June 2008 and coolant level has been stable since then. So, if your coolant slowly "evaporates", start looking for the leak. If you need to top it off more than once a year, it's leaking somewhere for sure. :sick:
By the way, I couldn't find any break-in instructions in my Camry 2004 manual. So, I was just taking it easy for 2,000 kilometers.