Camry head gasket issue brewing?

[Fifth87]

So, this is either a cooling system issue, or something that I am way overthinking- so I am submitting it for any and all thoughts. 02 Camry, 2AZ-FE, 237k. I have noticed the following after any prolonged operation: Rigid upper radiator hose, radiator cap that you can touch without being burned. Overflow bottle at hot mark, with no bubbles. There is a minor wander of the temperature gauge, between two hash marks- within what has been the operating range since I got it. I replaced the sending unit with an OE part which helped a little bit. No smoke/steam is visible from exhaust. When shut down, the coolant level rises approximately ¼ in in the bottle over the full mark. I have owned the car for 4 years with 93k of driving, exclusively all highway. There is no coolant loss or oil/coolant mixing. I replaced the radiator approximately 12k miles ago due to seepage at tanks with a Denso aftermarket unit and an OE cap. Car hasn’t been overheated during my ownership. Coolant has been changed after 50k interval, as were the radiator hoses and clamps with OE parts. Water pump appears to be original, nothing coming from the weep hole. Car runs and drives fine- asking as I am budgeting to overhaul the front end and don’t want any surprises. Next thought was to pressure test the cooling system and to test for combustion gasses in the cooling system.

Apologies to all for the wall of text.

 

[MrBubba]

After prolonged operation the radiator hoses and radiator cap isn't going to be cool it is going to be hot, my 1MZ-FE radiator and hoses were very hot after a 600 mile drive as was the oil dipstick.

If it is not overheating and there is no leaks, signs of air bubbles and you test it for combustion gasses, no indication of oil coolant mixing then unfortunately there is no other way to know if a head gasket is failing until it becomes symptomatic.

 

[charbaby]

IDK, remove the radiator cap and burb the system by squeezing & letting go of the lower radiator hose several times and see if you get any air bubbles or spitting coming from the radiator. You may have trapped air in your system. These Camrys don’t have many issues but, it is 24 years old w/237K on it so anything could be going on right now.

 

[GSCJR]

I replaced the sending unit with an OE part which helped a little bit.

Now it's time for a genuine Toyota thermostat; keep us posted.

 

[Hirev]

It could be you have air in your system. On my scion with the 2.4L I have to jack the front end very high to get all the air out of the system.

 

[mk378]

First, with it completely cold remove the radiator cap and check that the radiator is full. Checking in the bottle doesn't tell much. Once the radiator is full cold, start the engine cold with the cap off and rev it. If you don't see any bubbling head gasket is likely OK.

Second you should read live data and confirm actually overheating and not just the gauge. In older cars, the PCM uses a different sensor than the gauge and that's probably the case with yours.

Third yes the thermostat is suspect.

 

[Fifth87]

Thanks to all who have replied so far!
I have a new Toyota thermostat ready to go. I did burp it of air, but it never did occur to me that I didn't get it all, nor did I elevate the front end at that time. I can plug in my scan tool for the drive to work tomorrow. Finally, I won't leave you all hanging, I'll share the end results.

 

[The_Jeff]

You're overthinking, IMO, and going at it with all the old wive's tales except for putting pepper in as stop leak.

The radiator and cap can be cool-ish if the ambient air is cool. A properly working thermostat will keep 95% of the coolant within the engine and heater circuits, just letting a little to the rad where it's instantly cooled. The cap has a rubber seal and seals to a plastic neck that doesn't conduct heat; it won't be as hot as if it were on an older brass radiator. The coolant surge tank behavior after parking (heat soak) is normal.

I had one of these cars from 197k to 247k miles and the temp gauge was rock solid. They're dampened, too, so I expect your scan tool data to be significantly all over the place. But that can be fixed with the OE thermostat you're hinting at replacing.

As far as getting bubbles out, I like do an initial fill and 30 second run, then disconnect the top radiator hose at the radiator and stretch it into the air. I back-fill the engine through that hose until a dribble comes out the radiator nipple.

 

[71Chevyguy]

I would change the thermostat, been in there way too long.

 

[skyactiv]

Google Toyota TSB-0015-11

 

[Fifth87]

Google Toyota TSB-0015-11

I was aware of that TSB vaguely, but wasn't able to locate it, I appreciate you sharing the number. My car is a very early '02 model, built in July of '01 so definitely fits. If purging the air again and swapping the thermostat doesn't change anything- that may be next on my list. At that point I will be at the mercy of a shop as I don't have the time to do that work.

 

[Fifth87]

Ok, drove home from work live streaming the data from my scan tool. Temp was 167-176f, speed was a consistent 65mph for 40 minutes, outside air temp approximately 58f. The high was observed following pulling away from a toll plaza, the low while coasting downhill, cruise engaged the whole drive. Brief acceleration didn't change much, non mathematical average was 172.

 

[Nac Mac Feegle]

It might actually be running cool. Anecdotal data point: I have a 2006 Camry w/a 2AZ-FE engine and 285k on it. Ours runs 182-184F in normal operation as measured by a scan tool (Linear Logic Scan Gauge II) that is permanently plugged in. It will occasionally drift higher when driving and of course when sitting in traffic, I think the fans start at 202ish. If the A/C is on it rarely wavers from the normal 183+/-1F. It's remarkably consistent.

 

[The Critic]

I was aware of that TSB vaguely, but wasn't able to locate it, I appreciate you sharing the number. My car is a very early '02 model, built in July of '01 so definitely fits. If purging the air again and swapping the thermostat doesn't change anything- that may be next on my list. At that point I will be at the mercy of a shop as I don't have the time to do that work.

I'm surprised yours has lasted this long; maybe you got one of the good ones? I don't think any shop will want to go that deep into a motor of this age, so you're probably on your own if you want to repair this.

 

[6.7 CTD]

I just picked up a 2002 Camry with the 2azfe, and it had a head gasket issue I wasn’t aware of. Check to see if you’re cooling fans are working. Turn on AC and see if they’re on. Unplug coolant temp sensor (pic and part number below) and see if fans kick on high. Sensor may be bad. I wasn’t sure if you replaced the coolant temp sensor or not. Mine had no coolant in oil or vice versa. The intermittent bubbling in the coolant overflow improved slightly after replacing with an OEM rad cap. Fans only kicked on when AC was on or coolant temp sensor was unplugged. Block tester showed head gasket was failing. In the process of engine swapping it now. I hope for your sake it’s not the head gasket. That job is a pita, so I decided to put a used motor in it. Pick up a block tester, it’s the easiest way to know for sure. I used the BT-500.

 

[Fifth87]

So, I swapped out the original thermostat for a Toyota replacement. There was no obvious mechanical defect to the old one. However, the rubber seal around it was worse for wear, with some aluminum corrosion at the sealing surface on the cylinder head. The water neck itself looked ok. Before I refilled the radiator, I noticed what appeared to be little bits of rubber in the drain pan, so I strained the coolant through a clean shop rag into the radiator. All I could think of was the hoses, but I am not going to give that much more thought at the moment, as the radiator hoses are recent within the past 3 years. Refilled the system with the car on ramps and purged what I thought was quite a bit of air out. It is running hotter for sure, firmly in the middle of the gauge, without wandering. Coming home from work I’ll hook up the scan tool so I have some data points to compare.