6G Celicas Forums

Car:
1997 Toyota Celica GT

Location:
Central California(It's pretty hot nowadays since it's hitting summer)

When I started to notice the overheating problem:
My car ran with no over heating problem until AFTER I replaced both the ECT sensors because I had a P0115 CEL code. When I had the code my car would start then idle rough and then stall. So I bought an OBD2 CEL reader and I had the P0115 code. So I replaced both the ECT sensors and the CEL went away. The next day I was driving to Fresno(45 min drive). It drove ok(but I'm not sure because I didn't keep an eye on the gauge) until I started the car again about 6 hours later. At first it was at the correct temperature until about 15 min into the drive and I noticed it jumped up to 70% and back down. That was how and when I started the notice the over heating problem.

Problem:
Overheats once the car has been driven for about 30-40 min. My normal operating temperature is about 45%. When it starts to over heat. It'll jump up to about 65-70% then back down to about 50%. Then slowly to 45% again. Then like after another min it'll jump back up and repeat the process.

I noticed that when I was at a stop. The fan kicked in and the temp gauge jumped up to about 55% then slowly up to 70% then back down to 50% again.

EDIT: Just got back from testing my car and it seems to like to heat up to about 60% right until the fan kicks in. It'll drop to 45% then immediately and slowly climb back up to 60% and then stays there until the fan turns off. It'll slowly crawl back down to 45%. And it repeats itself. I'm thinking I might just have a faulty Coolant Temp Sensor, the one that goes to the ECU and not to the Dash. This was all done while the car was idling. Any ideas?

What I've done so far in order:
1st- Replaced both ECT sensors. 2nd- Replaced thermostat. 3rd- Replaced upper radiator hose. 4th- Flushed out the cooling system. 5th- Bled it out correctly. 6th- Replaced the radiator cap & bled it again. 7th- Checked for leaks, there were none. Coolant level stays the same.

EDIT #2: Ok. So here's an UPDATE. So. I let my car idle and heat up to about 70% and I just let it idle. It kept jumping when the fan turns on and off so I decided to unplug the sensor/switch so that the fan will always be on. When I did that trick. The gauge went down to about 45% and stayed there and never climbed or jump?

When it's connected. The fan will turn on for about 2-5 seconds max. I know that's too short. I think that's why I'm getting these problems. My fan is just not turning and staying on for the right amount of time. What I did was replaced the radiator and the fan switch. So I don't know why the fan isn't staying on for the right amount of time? Any ideas?

EDIT #3: Ok so I finally took it into a shop to test it out and they said my car is not overheating but the ECT unit isn't grounded properly because I had teflon tape on the threads. So I bought a new ECT sensor and installed it without the teflon tape. Results are NOTHING! The only relief is that it's not overheating at all. The gauge on the cluster is saying it's over heating but it really isn't. At least that's according to the mech I took it to. Any ideas about the ECT, PCM, and etc.???

This post has been edited by ILoveMySilly97: Jul 18, 2012 - 7:21 PM

Yea it's blowing out water to the overflow bottle. That should mean there's good pressure. Right?

Is your Intake Air Temperature sensor plugged into your air intake, after the filter?

No. That means the cap is seeing enough pressure that its valve is opening to allow water out. If the cap is an incorrect rating, isn't on properly, or is not functioning correctly, then the pressure in the system and subsequently the temperature will be incorrect as well.

There's some simple tests for the temperature gauge. Disconnect the sensor (on the water neck, single-wire sensor) and ensure that the gauge reads cool. Ground the connector through a 3.4W test bulb and turn the ignition to ON; the gauge needle should move towards HOT. The gauge may also be checked at the cluster, for resistance. Unfortunately, I don't have access to the sixth-gen's BGB so I can't tell you which terminals on the back of the cluster are involved in testing.

I'm going to have to keep that in mind. I just finished troubleshooting my car earlier. But I'll do this test tomorrow.



Which sensor is that? Is that the one that looks like a probe that's inserted into the intake piping?

So today I decided to replace my lower radiator hose because I noticed it was leaking a bit at the water outlet. When I went to remove the hose the water outlet actually broke off. It was worn out and old. Since it was plastic, it was reasonable to why it would be like that. I went to AutoZone and replaced it with a cast iron water outlet.

What I did today was replaced the lower radiator hose, replaced the water outlet, flushed the cooling system AGAIN, and bled it AGAIN. Took it for a run and it had no progress. It was still jumping. -_-'


^This picture. You can actually see a piece of the water outlet stuck inside the hose^







This post has been edited by ILoveMySilly97: May 29, 2012 - 10:52 PM

same problem no fix

Well. I just installed a new radiator fan switch and no progress. I already ordered a Spectrum Premium radiator off of Amazon. Should be coming in sometime in 3-5 days. If this doesn't fix it.....then I'll just hope it's not a blown head gasket. I have no obvious signs of a bad head gasket YET at least. No milky oil or coolant.

yea same here n i just put in a new rad.

Damn. Now that I think about it. I could've spent all that money I spent to replace working parts to a shop that could've done a diagnostic check on it. -_-'

^^^This single post above should have its own sticky

This is why components should be tested prior to replacement.

A pice of that old platic tube is probably blocking youtr thermostat openings mabey recheck the thermostat.

In your other thread on this issue -- you really should keep it to one thread -- you mention you installed a 170 thermostat. If you mean you installed a thermostat calibrated for 170 Farenheit, you put in the wrong thermostat. The 5SFE is designed to work with an 82C/180F thermostat. That you're not using a Toyota thermostat makes me also wonder if what you installed includes a jiggle valve and a proper gasket.

Isn't it the lower the better? The degrees is only determines when the thermostat opens correct? So it wouldn't hurt to open a just a lil bit earlier. I mean it keeps the engine cooler. Or am I wrong?

I've just been through the same thing as you, No milky coffee oil/coolant etc. first the pipes corroded, then it overheated, tried flushes, trd stats, trd caps,... yep turns out block & head surfaces were way warped, gasket was leaking inbetween layers, it was just combustion pushing water out, there was no oil to coolant leak.

sorry pal, the more u drive it the worse its gonna get. rebuild it or get another motor now.

No, the engine is designed to work at a certain temperature range. If colder were better, Toyota could have skipped using a thermostat entirely to keep the engine near freezing when driving. Air-fuel ratios are adjusted based upon engine temperature. It's the same reason those chips which fool the ECU into thinking the air is colder are a bad idea.

Yea. I'm going to get my car diagnosed if replacing the radiator doesn't fix it.



So I should just go back and buy the 180 one instead. Might try to return the one I just bought since I still have the receipt.

Ok. So here's an UPDATE. So. I let my car idle and heat up to about 70% and I just let it idle. It kept jumping when the fan turns on and off so I decided to unplug the sensor/switch so that the fan will always be on. When I did that trick. The gauge went down to about 45% and stayed there and never climbed or jump?

When it's connected. The fan will turn on for about 2-5 seconds max. I know that's too short. I think that's why I'm getting these problems. My fan is just not turning and staying on for the right amount of time. What I did was replaced the radiator and the fan switch. So I don't know why the fan isn't staying on for the right amount of time? Any ideas?

This post has been edited by ILoveMySilly97: Jun 11, 2012 - 12:05 AM

Same idea as has been advanced before -- test the fan temperature switch. Also, test the fan itself.

4. INSPECT COOLING FAN
(a) Connect battery and ammeter to the cooling fan connector.
(b) Check that the cooling fan rotates smoothly, and check the reading on the ammeter.
Standard amperage:
4A–FE and 5S–FE 5.8 – 7.4 A

A $10 multimeter saves a lot of money by preventing the needless replacement of working parts.

You haven't mentioned getting your timing corrected. If that's the cause of overheating, all this other work won't fix the problem.

This post has been edited by Galcobar: Jun 11, 2012 - 5:13 AM

Cooler is not necessarily better. This thread is getting clogged with garbage (including this one). If the fan stops running, give it a spin and see if it runs on its own for another 3sec. If it stops, its fan time. Also that nonuniform thermostat could be throwing a wrench into the system. If that fails, check back in. We'll get this thing worked out!