OK. Well my name is Matt and I'm new to this forum but I'm really hoping that you camry specialists can help me here. Well here it goes. Specs. 1993 Toyota camry le 2.2. I bought this car 12 months ago and its a great car. Bought from orig. Owner old lady that had all scheduling maintenance done on time. 114,000 miles currently. About a mnth ago the thing would start to overheat. So I flushed the system, put a new water pump and thermostat in it. Still overheated and I noticed bubbles in the radiator and overflow so I determined it was the head Gasket. I Am a certified mechanic so I put a new hg on her with all bolts torqued down to spec including new head bolts. Gasket only goes on one way. Now it currently does not overheat however when I look under the hood after driving under heavy load like the interstate I can feel a small amount of bubbles moving around in the upper radiator hose. It's driving me crazy. I didn't think there were supposed to be any bubbles in there at all. When I had the head off I checked it with a straightedge and there is no signs of warpage. I did not bring it to the machine shop. I do not believe there are any cracks or anything because there is no evidence of this. No oil in the cooland and no coolant in the oil. The car runs fine. I even did a cyl leakkage test and I got 36% in cyl 123 and 27% in cyl 4 which is a little high but still does not suggest a leak . Also all the air was purged by running to op temp with the radiator cap off. Any expierience with this would help me out alot. The car runs fine. Thankyou for your time guys. Matt

 

A failed heat gasket is uncommon on this engine unless overheated into the red.

There is always some air left after system refill but once run to operating temp and topped off the air should be out.

Have you pressure tested the coolant system for leaks other then the head gasket, checked radiator cap, hoses, etc? Any issues with the overflow system causing air to be drawn into the radiator?

Head gaskets problems often being a puzzle of unclear symptoms suggest a block test for exhaust gases in the coolant.

 

i have indeed pressure tested the system, and it drops a few psi but the test was done when the engine was still hot so a little drop in pressure is normal to compensate for the fluid cooling and lowering in volume, i guess i need to pressure test it when it is completely cold and make sure it doesnt drop at all in a 30 minute period. i guess that would be my next step, after that i guess ill need to try and locate a exhaust gas analayzer to test the coolant. even today, its been 2 days since i swapped out my coolant again, and i know all the air must be out, but when i just got home i can feel bubbles moving through the upper radiator hose and into the overflow, i took the cap off the overflow and i can visually see a few bubbles every couple of seconds, but the car is NOT overheating, the needle sits just a tad below half way mark and does NOT fluctuate or move at all throughout my drive home.... im just perplexed, should i not worry about this ? i mean i guess if im not seeing any adverse affects then i shouldnt worry???

 

The needle position you describe is normal.

If the engine is not overheating or otherwise acting unusual suggest taking a wait and see approach. If still bubbles in another week then might look closer.

Monitor the coolant level in the overflow tank to make sure sooner or later it stabilizes at some level.

If have the time do a cold pressure test.

Make sure the radiator fans are working normally.

 

you can SEE air bubbles through THICK radiator hose wall?????

those are some bubbles then...

did you purge air from the system when you did refill? only thing I can think off. being a mech, you also know that intake manifold gasket can leak air inside. Japanese, also, have weird approach to running tiny coolant lines to strange devices around the engine. Like coolant warmed idle speed valve...

 

no i cannot " see " bubbles through rubber hose... i use other senses i.e. sound, touch, to determine that there are is in fact cavitation within the hose... but yes i purged all the air from the system, i left the rad. cap off and let the car run up to operating temperature, i agree with you, i will drive it for a week and monitor the overflow level, tomorrow im going to put a pressure tester on the radiator and do a cylinder leak test with shop air and see if the needle goes up on the pressure reader, also ill stick a stethascope in the radiator and listen for bubbles, if no progress , just going to drive for a week and monitor overflow level. thanks again guys. getting further every day one step at a time, ill keep you guys posted.

 

Check to see if the water pump is intact. If it's missing one fin, you might not overheat, but some coolant that is still in vapor form could be escaping back into the radiator. This would also explain bubbles in the overflow tank.

 

the water pump is brand spankin new sir. its intact

 

yes Sir, you "feel" them in the hose. My bad, but it was cool to say.
well, not every system is purged by simply opening radiator cap.
1. t-stat must be opened
2. heater core must be "in-line", meaning, heat turned to max
3. some systems have coolant lines highest point above radiator cap, and have special purge opening, usually, in t-stat housing.
you prolly have it all covered, but just in case...
oh, and some palpable coolant movement in a hose is pretty darn normal. like you said - cavitation, plus normal fluid flow. hoses ain't polished inside for laminar flow, as you know. bends have re-enforcements inside, like coils.
you might be simply over reacting..

 

hmm, you may be right, im gonna do some more tests and tinkering tomm. ill keep you guys posted. thanks for the help too