'95 Camry Overheating

[Camry1999]

Hey Everybody,

I apologize ahead of time if this is a re-post but I thought I would make a new thread to explain the situation in detail. So, we took my mom's '95 Camry to a picnic about 35 miles away. we had the A/C on (on the Low position) & 6 adults. For the first 20 miles, everything was great, the engine temperature gauge was about right in the middle. But then I started noticing that the needle would raise up slightly when the RPM's went passed about 3,500-4,000 RPM's. We made a couple trips to some stores w/the A/C on full & it was fine then. But, on the way back, we had the A/C on Low w/the same 6 people. After about 7-8 miles, the needle went up about a little higher than 2/3 of the way up & stayed there. So, I turned the A/C off, & even the air off all together, no difference. I had to roll the windows down & put the air on full blast to bring it a little below 1/2 way. I flushed the anti-freeze and it looks just fine. Does anyone have any ideas? I was thinking either the thermostat or the water pump. The fan does go on & off normally, if anyone has any ideas, please let me know.

[71Corolla]

I would start by replacing the thermostat, it's really easy on your car. I highly recommend you use only a Toyota part, not aftermarket. Does the coolant level drop over time?

[JohnGD]

At what speeds was the car overheating. Highway, street stop-and-go, both?

If it's doing that on the highway I'd check the radiator and coolant circulation. If local I'd first check the radiator/AC fans.

[dc_98_cam]

+ 1 on replacing thermostat .... just routine maintenance.

How many miles on your vehicle?

[Camry1999]

Thanks for the replies. The coolant level is just just fine, it does not drop, also, is has about 96k miles on it

[TOYOPARTSMAN]

First process of elimination is to replace the thermostat and gasket, next is to make sure your radiator isn't clogged and gets good circulation. But I'd definetly start with the T/Stat.

[fenixus]

I agree with thermostat+gasket as a first suspect and cheap replacement (not counting coolant refill).

However since you recently flushed the coolant, then make sure that you have no air in system. open the rad cap, does it make this "pssst" sound? is the coolant up to neck under the cap?

If first answer was yes and second no, then you have air in system, top it off, let the engine run and squeeze the upper rad hose a few times and make sure it's hard to touch and not soft and empty inside. when system is properly pressurized when warm, it will suck the coolant from overflow tank when cooling down. if the coolant level in overflow tank does not change between hot and cold then there is something wrong.

faulty rad cap can also leak and cause the whole system to be unable to build pressure. in result the boiling point of coolant mixture shift closer to water boiling temperature (only 212F which is VERY close to normally operating engines like 5s-fe at idle after some highway driving).

[Stillrunning]

How old's the radiator and how often have you serviced the coolant since 1995?

[Camry1999]

fenixus: I am going to check all these things out tomorrow. it had a lot of rust in the antifreeze which I finally flushed it all out & refilled it w/the pink antifreeze I got from the Toyota dealer after I was completely sure there was no rust left. I am going to get the thermostat tomorrow from the dealer, I hope it's not a special order.

Stillrunning: I want to say that the radiator was the stock one judging from all the rust inside of it. I will start w/the thermostat & see what I am going to do from that point. Also, I just remembered that we did change the water pump last year w/the timing belt.

[fenixus]

you using Toyota PINK premixed coolant (Super Long Life) ? this one was NOT designed for mixed metals in system and has absolutely no protection against brass/copper corrosion if I remember correctly, new systems are fully aluminum.
Old systems are mixed metals (iron, aluminum, brass, copper, etc.) and call for Toyota RED coolant (Long Life) which comes concentrated and needs to be mixed with distilled water (around 50/50 is good).

just saying, since you will be draining it soon, might be a good time to fill it up with correct Toyota coolant while doing the thermostat and its gasket.

[Camry1999]

Okay, so I have been playing around w/some stuff. If it's pushed hard (A/C on or off), say about above like 3.5k RPM's, the needle start going up, use the heater for like 5-10 secs & it drops until you push it hard again. IMO, the fan does not come on as strong as it should. It stays on way too long& shuts off for like 5-10 secs & then just stats in a again. Usually of the fan is on @ full force, you can hear from inside the cabin, but I can barely hear it when I am next to it. I am going to change the the thermostat & possibly the antifreeze. It was little low, but even after I filled it, it is still overheating

[fenixus]

if the level dropped in a fairly short time (e.g. less than 6 months) then you may have a slow leak somewhere, which could be affecting coolant pressure and what's worse sucking air into system too ...

try new thermo and fresh coolant first (and remove all air afterwards) and I would also get a new radiator cap from dealer, old one might be leaky.

If that does not solve the problem, I would pressure test the cooling system at some local shop and see if there are leaks anywhere, look at hose ends and see under car fi anything drips to ground.

[Camry1999]

Okay, so I changed the thermostat and the engine temp sensor which is located right below the left fan, no change @ all. There is still I significant amount of rust in the radiator. So, tomorrow morning, I am going to take the radiator out of the car, take it apart, & put some CLR in it to see if it will take the rust out. If not, I am just going to buy a new radiator which is like $90 @ AutoZone for an aluminum one.

[dc_98_cam]

+1

[JohnGD]

Don't use Toyota pink or coolants with 2EHA. The pink is meant for all-aluminum engines. The 2EHA is a plasticizer that can cause leaks with Nylon 6,6 and silicon rubber seals.

Notice the "PA66-GF30" molded into the top tank of the radiator and thermostat housing? That's Polyamides 6,6 (Nylon), 30% glass fiber reinforced. I wouldn't use Death-cool or All-Makes with 2EHA in there.

The rust came from the block, so you should flush the block too. Try Valvoline aluminum safe flush chemical:
http://www.valvoline.com/products/co...-treatments/45

And refill with Toyota Red, or after flushing with distilled water, Valvoline G-05, with 50% mix of distilled water.