Engine overheat?, Diagnose this for me! Options

[gts4]

Hey. I drive a 94 gts. Basically, there appears to be a small oil leak, and I had rad blow on me. I replaced it, but my temp gauge tends to redline after 45 min of driving. Sometimes, it stays high, then dips down to 40%. It goes up and down.

It seems to go up when I downshift and hold it at 4-5k rpm.


Other times, it just moves by itself. Any ideas? Thanks!

Update. Found an oil leak on the valve cover gasket. Will fix it this week. Will check the thermostat after the leak is fixed.

Edit: I'm having another issue. The celica won't turn over. After shampooing and pressure washing the engine yesterday, my celica would stall at a red light. I barely got it going again, but made it home. It was turning over and started after 3 tries. This morning, it turns over and chugs without starting. What's the issue? Did I flood anything? Should I check the distributor?
Solved the starting issue! Distributor was fine. Switched to iridium spark plugs. Starts better than a new car
Thanks everyone!

This post has been edited by gts4: Feb 9, 2012 - 12:35 PM

[mkernz22]

I'm thinking it could be a blocked thermostat, but don't quote me on it.

[bsamps4]

You have a blown headgasket sir

[mkernz22]

if the oil and coolant are mixing, then he'd have a blown head gasket and/or if there was coolant getting into any of the cylinders.

[PolliS_5S-FE]

You're in for a world of fun

[gts4]

I'm thinking it could be a blocked thermostat, but don't quote me on it.

Too late.



Thanks everyone, I engine shampooed my car today. I'll be looking at it tomorrow.

The coolant levels seem to be okay. How do I diagnose the mixing of oil and coolant? How do I know if it's a head gasket?
I'll look at the thermostat too.

Is it safe to drive this way?

[Smaay]

do a compression test, look at the oil. it would be milky.

[Galcobar]

Thermostat's fairly easy to test, it's just that it means you drain half the coolant out to get at it. Given a thermostat is US$15 even from Toyota (via 1sttoyotaparts.com or Lithia Toyota; I would not buy any aftermarket thermostat, except perhaps for a Stant) and involves only a couple of nuts (or five if you have to remove the AC compressor) it's an easy fix. That said, it's even easier to check the condition of the coolant first.

Milky = oil and water mixing, blown HG. If it's clear, check that the radiator cap is working -- the reservoir bottle should fill as the temperature and pressure in the cooling system increases. After that, you're probably looking at a replacement thermostat; test that by feeling the coolant hoses. A cold hose indicates a lack of circulation, which points back to your thermostat or your water pump. If you have a circulation issue, hope that it's your thermostat.

[Hanyo]

Thermostat's fairly easy to test, it's just that it means you drain half the coolant out to get at it. Given a thermostat is US$15 even from Toyota (via 1sttoyotaparts.com or Lithia Toyota; I would not buy any aftermarket thermostat, except perhaps for a Stant) and involves only a couple of nuts (or five if you have to remove the AC compressor) it's an easy fix. That said, it's even easier to check the condition of the coolant first.

Milky = oil and water mixing, blown HG. If it's clear, check that the radiator cap is working -- the reservoir bottle should fill as the temperature and pressure in the cooling system increases. After that, you're probably looking at a replacement thermostat; test that by feeling the coolant hoses. A cold hose indicates a lack of circulation, which points back to your thermostat or your water pump. If you have a circulation issue, hope that it's your thermostat.

this has been the best response for far in this entire thread.


I would like to add.

Before you do anything with your car. Check to see if your temperature sensor is malfunctioning. Your gauge can be going wild because the sensor is faulty causing your needle to fluctuate and your radiator fans from turning on.

There is no way we can tell you whats wrong with your car unless you do some diagnostics first.

Does your engine get hot?

Does your engine boil out all the coolant?

Do you hear any water sloshing sound driving and during start up?

Does your heater work?

Do you have excessive white smoke coming out of the exhaust?


How you answer those question determine what the repairs will be.

Good luck

[gts4]

Thermostat's fairly easy to test, it's just that it means you drain half the coolant out to get at it. Given a thermostat is US$15 even from Toyota (via 1sttoyotaparts.com or Lithia Toyota; I would not buy any aftermarket thermostat, except perhaps for a Stant) and involves only a couple of nuts (or five if you have to remove the AC compressor) it's an easy fix. That said, it's even easier to check the condition of the coolant first.

Milky = oil and water mixing, blown HG. If it's clear, check that the radiator cap is working -- the reservoir bottle should fill as the temperature and pressure in the cooling system increases. After that, you're probably looking at a replacement thermostat; test that by feeling the coolant hoses. A cold hose indicates a lack of circulation, which points back to your thermostat or your water pump. If you have a circulation issue, hope that it's your thermostat.

this has been the best response for far in this entire thread.


I would like to add.

Before you do anything with your car. Check to see if your temperature sensor is malfunctioning. Your gauge can be going wild because the sensor is faulty causing your needle to fluctuate and your radiator fans from turning on.

There is no way we can tell you whats wrong with your car unless you do some diagnostics first.

Does your engine get hot?

Yes.

Does your engine boil out all the coolant?

Quite possibly. I had to top up my coolant this morning.

Do you hear any water sloshing sound driving and during start up?

No.

Does your heater work?

Yes.

Do you have excessive white smoke coming out of the exhaust?

No smoke.

How you answer those question determine what the repairs will be.

Good luck

Here's the thing. After my shampoo yesterday, I cannot get the celica to turn over. I can't start it. It cranks over, but doesn't start. I hear the fuel pump when I'm in the on position. Someone told me it may be the distributor. This used to happen once a month, but would eventually start. The last owner said there was a short not worth fixing. I changed the battery 4 months ago. This may help: On the way home from the engine shampoo, my celica would stall when I stopped at a light. I would barely get it started, it would chug like it does now, but still worked. Now, it just chugs / cranks over with no startup. Could I have flooded something?

Help with this?

[PolliS_5S-FE]

you need to check for spark. its most likely to be electrical fault after a shampoo

[bnr32celica]

That water sloshing sound...I have that even after all my repairs, I think it's fairly normal.

My car was doing what yours was doing (I had a rupture between the 2-3 exhaust ports, causing my car to look like Old Faithful after a hard run), I ended up doing the head gasket, thermostat, coolant FLUSH, and water pump. For good measure, I replaced the sensor as well.

For the record, I started small with the thermo and fresh coolant. Drove it particularly hard, and ended up watching coolant shoot 6 feet out of my apparently busted radiator cap in my driveway. Looked like the Diet Coke bomb, and that was after a commercially available flush product and fresh coolant were installed.

At that point, my dad and I decided to go ahead, drain whatever was left, flush again, let everything cool, and yank the head. My gasket literally had a rip in it between 2 and 3 exhaust ports. I also found coolant galleys completely blocked in the head and block. Did the best I could with the block using air, a garden hose, and pipe cleaners. We did not remove the block and trans, however, we did send the head out for machining (my head took 18thou to get true), and I paid an extra $200 for new valve seals, an adjustment, and a nice hot bath.

While I waited the morning for my head to be completed, we installed the new water pump, timing belt, pulleys, and everything else we could. I also cleaned the mating surface on the block with my air grinder and wire brush. One thing I also did (and you should too, Toyota coolant is the worst I've seen for forming deposits, I switched to DexCool) was send my radiator to get boiled out porfessionally. Cost me $50, totally worth it though. It's basically a nice hot bath at 100psi plus for your radiator. Some of the stuff they removed was some of the worst they have seen.

Total time and cost for everything was somewhere in the $600 range and 8 hours (I spent just as much on services as parts), but now I have a happy 5s that doesn't burn or leak coolant anymore (and also has WAY more power).

You're probably doing what I did last Saturday. If you have to pay to get it done, it might not be worth keeping the car. I got quotes, and they were all over $1200 for just the head gasket and machining. I'm a busy guy (I work 90 hours a week), but I had to budget 8 hours over 2 days to get it done. We did 2 hours day 1 (teardown), and then day 2 we just knocked it out. It's not a hard job at all, just time-consuming with a good amount of downtime waiting for services (we got lucky and know the owner of a machine shop who took my head right in). I could have done this in my sleep (and for the first couple hours of day 2, I was), and it would have come out fine.

My car would only smoke when it got hot btw.

I also wouldn't have shampooed the engine, I use simple green and a rag. Yes, it takes longer, but also doesn't cause my car to not start.

[bsamps4]

if the oil and coolant are mixing, then he'd have a blown head gasket and/or if there was coolant getting into any of the cylinders.

Oil and coolant do NOT always mix when a head gasket is blown. It depends where the breach in the head gasket lies. Premature breakages can cause these type of issues where driving the vehicle cools the engine, and sitting at stop lights burns it up. If you are revving your engine to make the temp gauge go down, then your headgasket is likely the culprit. There are SEVERAL symptoms that a bad head gasket can present.

[celicomx]

if do you need to rev your car to get it cool down they are only 2 reasons that are causing this:

1-. Thermostat dont opening
2-. Bad Water pump

Start with the cheapest