Update: haven't had time to check things out too much,I do today. Thanks again for all the input. Just some things I I noticed today when driving:

AC is running fine now,I checked the fuses and they were OK and when I put them back it ran fine. So that's that for now. Also within first 5 min the temp gauge is fine but after that it goes up to 3/4 mark. I noticed that when driving at highway speed it stays at 3/4 but when going to more urban driving it moves up almost to the red mark,then it goes back down to 3/4 when I pick up speed on a highway. Not sure why this happens.

Also seems to be a leak,there was fresh fluid under front of car,I think it's oil,need to investigate further. I'm letting car cool down now so will have more updates after I do the checks and testing we discussed. Thanks update soon

 

At hwy speeds, more air and coolant (via the water pump now turning faster) flows through the radiator. This lowers the coolant temp.

The thermostat's job is to regulate coolant flow to maintain a constant temp (steady temp gauge indication).

Make sure the thermostat is working properly.

Air in the cooling system can also cause major temp variation. Make sure all the air is out of the system.

A low coolant level can also cause problems.

Place cardboard under the car to catch the oil. Then use the location on the cardboard to narrow down the area of the engine from where it drips.

 

Ok so everything inside the ending seems fine,pretty dirty so I've been cleaning valves and connections etc. I'm in the process of burping the engine right now on my day off. I'm also going to look at the fuel tank wiring.

Do you think it's worth testing the fuel pressure? The car seems to he running a little smoother now,I was being hesitant to drive normally but when I do it seems to over come some of the rough driving but it's still there. Maybe just some of it is the old age and high mileage? There's still def something going on . I have a full day today to inspect so I will. Thanks

 

What is the knocking you referred to when driving?

Have you checked the ign system? The spark should be able to easily gap ½in of air and be white.

153K miles is not that much unless the engine was abused.

What is the engines idle speed hot and cold? Should be around 1200 when cold and first start up then around 800+/-50 hot. If too low the engine will vibrate.

Have you cleaned the IAC valve (not the throttle body)? The IAC valve controls idle speed.

The can type fuel filter under the hood seldom causes problems. The symptoms of plugged filter are constant low engine power.

Does the engine have power when going up hills, accelerating, etc? Lack of fuel causes lack of power.

The coolant temp sensor for the computer signals controls the idle, fuel, etc based on coolant temp.

 

Ok engine idle speeds are pretty much right on the numbers you described. I burped the coolant system 3 times to no avail,the temp gauge still rises. I played with the sender switch,,its on as good as it can be. The cables all seem fine when manually moving them. I cleaned the IAC valve very well,the car starts smother now . I think the vibrating is back to normal amount for a Camry. It's not as aggressive as before when idling.

The main concern for me now is the temp and the rough driving. I'm going to take a coolant temperature today I'll inform you on that. I shouldn't have used the term knocking when describing what happens. It's more a rumble under my feet at high speeds or when I let off the gas. The car gets uphill but it could be faster,it doesn't take off at any time how it should when accelerating. So it's the rumbling,the rpms not flowing or dropping smoothly,bad accelerating and the temp gauge. I'm going to take the temperature and possibly look at the thermostat? Is there any tips on what to look for and the beat way to access the thermostat?

Also the AC is blinking again. All fuses Ok. Could it be compressor?

Lastly the leak under the car is oil,not major leakage but a leak none the less. It seems to be far left on engine from the middle/back area away from the front of engine. Not sure specifics on that yet,have to investigate. Thanks as always for the input.

 

Update: leaning towards thermostat being the culprit to the overheating issue. Nothing else is a problem unless he sender switch is faulty I. The lower rad hose is leaking but only started when I started playing with the housing itnconnects to. It's not ripped but coolant is seeping out of the top where it connects to the housing. It wasn't before but I cleaned the area and it seems the corrosion was acting as a seal. The hose isn't working properly. I'm going to change the hose and then check out the thermostat.

Any tips on what to look for when looking at the thermostat? What should I be looking for in terms of problems?

Still attempting to narrow down the oil leak and the AC problem.

The rpms are still rough and at high speeds the car seems to rattle and when letting off gas pedal after speeding up,there is a rumble(don't know how else to describe it,under my feet and I can feel it rattling/rumbling.

So certain things get better and some worse or stay he same lol. I can't catch a break. Thanks for all he input.

 

To test T-stat operation. Note the temp stamped on its body such as 180F.

Place T-stat in heating water with thermometer. Note temp when valve on stat starts to open and temp when valve is fully open.

If 180F stat valve should start opening between 176-183F. Then open be 0.335 inch at 203F.

When removing the T-stat note were the location of an air bleed hole is on the outer ring of the stat with the stat installed. This hole should be oriented up.

The hole needs to be at the top.

For oil leak check area around lower circumference of the timing belt cover for signs of oil. This including the bulged area in the cover located midway on the side closest the firewall. Also check for a slow drip with engine running from these areas.

Other areas of engine oil leakage are back of valve cover and down back of engine. Distributor, oil pressure sensor, gasket between engine oil cooler mount and block (if installed), oil cooler lines.

Try to determine if the oil is transmission or power steering (same) or engine oil.

Rumble can also be do a problem torque converter if having auto trans.

For AC issues suggest obtaining some type of service info. Haynes has a pretty decent low cost ($20) shop manual.

 

I replaced the thermostat,the old one started opening around 190. I replaced it with new o ring and gasket as well. I am driving soon so I will know if that's the problem or not.

Also changed the pcv valve because the grommet was basically gone on old one and thought it may help overall performance. However now the cold idle is 800 not 1200. I put the new valve on correctly and well,I have to double check cuz that must be why that happened right?

I also just found a long skinny rubber piece of something hanging,but still attacked near the belts to the left of engine. The one thing I don't know well are the belts. I can take a pic for you to help you see it. It's hard to describe,something must have torn or ripped off. No problems running that I've noticed yet,about to go check everything out.

 

Ok so it wasn't the thermostat even though it was a little slow to open. With the new one in the temp gauge still rises. I think it has to be the sender switch,can it be the wiring? Not the part that goes into the plumbing? I'm also going to replace the ect switch next to it for good measure/overall performance.

The idle numbers seem better now,I think the car was adjusting to the new valve. The rpms are dropping on their own and the car is accelerating better. Will drive on highway soon with it.

The piece of rubber seems to be ripped off the edge of the smaller belt in the back,it operates fine but I'm still concerned,something must have ripped it.

 

Alright so I checked the plugs they most certainly needed to be changed and my moms BF had a new set of plug wires/boots so I used them as well. The cars performance is definitely better,I replied earlier to the spark plug thread I made,there are details and questions there if anyone can help.

A quick explanation of what I wrote: the car accels better,better pick up,drives smoother etc. The only thing I'm noticing is the rpms going down too slow? It only happens when I'll get up to highway speeds(65) and 2000 rpms. They move fine and smooth every other time but I'll get up to 65 and the rpms seem to not want to go down from 2000 quick enough when I let off pedal. It may just be the car running for all I know,just something I noticed.

Aside from that,the car seems to be giving off an emissions smell more regularly than before. Not sure if it could be exhaust system,02 sensor,maybe cat converter? Any suggestions would be great. I've cleaned the throttle body,iac,manifold and some of egr valve lol. Thanks