Overheating drama


we have a 95 camry that has been leaking both coolant and oil since we bought it two years ago. We’ve had a lot of work done on it, and had a lot of trouble with the work being pretty poorly done from time to time (had to have 3 water pumps put on, for example, due to ‘bad parts used…’). For the last several months, the car tends to overheat while driving (city driving, never more than about 30 miles at a time, usually less than 10). We got it back into the shop last week and had the radiator, both radiator hoses and the thermostat replaced - had already replaced the old coolant overflow tank, the water pump (as mentioned) and timing belt. Unfortunately, it’s overheating more than ever since we got it back. We’ll call the shop when it’s open again on Monday, but in the meantime, any suggestions? Some online research has led me to think it may need to have air bled out of the coolant system (although I think it may still have a leak somewhere). Also we never see the fans on, so I suspect the relays may be bad (I asked the shop to check this but am guessing they did not…). What else should I be thinking of?

Forgot to specify, when I say ‘worse than ever’, I mean that the temperature gauge will shoot up to the red within three to four minutes of the car being driven, before there is any heat from the defroster (which does kick in after about 10 minutes). It’s right around freezing temperatures here right now, is it even possible for the engine to be heating up that fast? the radiator still feels cool when the gauge says ‘super hot… about to explode’

How many miles on the Camry?? The fans, both of them, should run anytime the A/C or defroster is on, regardless of engine temperature. Do they? They should also run anytime the engine temperature is above normal…

Now it sounds like the cooling system is not full. When it’s cold, remove the radiator cap and fill the cooling system with 50-50 mix…Does it boil over? Coolant being forced out of the overflow tank?

How sure are you that the thermostat was replaced? A stuck thermostat or one installed backwards can cause severe overheating very quickly, a cold radiator, and failure of the fans to operate when engine temperature is involved.
Both fans should run whenever the A/C is on or the mode control is in the DEFROST position. If the fans do not work in this manner then it’s possible there could be two problems.

Based on what I feel is an utter crock of BS about having 3 bad water pumps, the apparent failure to verify the car is not overheating, and the failure to make sure the fans are operative, I might say the shop could be suspect. Maybe very suspect.

And yes, it’s possible for engine temps to go quickly out of control even on a 10 below day. In almost every case this is caused by lack of coolant or a faulty thermostat.

I’ll dredge up a wiring schematic and post back with a tip or two on fan operation. Keep in mind the fans MUST run whenever the A/C is on or the mode control is in the DEFROST position.

A look at a schematic shows the fan operating system is a bit more complicated than normal (3 relays, control module, series of sensors, etc, etc.) so I won’t go into that at this point. It does use a fuse and 2 fusible links in the system so make sure that ALL fuses/fusible links are good even if they’re not related to the fans.

Seeing as how the car overheats so quickly this problem is unlikely to be related to the fans UNLESS the A/C is on, the DEF engaged, etc. and both fans are not working.

This vehicle cannot be continually operated with the temp gauge in the red. The car has aluminum heads, or singular head depending on the engine, and a head gasket(s) will eventually let go along with roasting the piston rings. The latter leads to oil burning.

Thanks for the quick responses - to answer a few questions, the camry has 160 thousand on it, When I bled some air out of the system this morning I verified that the fans are not coming on when the defroster is on, so that will be my next move - fuses and relays first, then check the motors, etc. It did not overheat today, but I kept the defroster on the whole time driving just in case… I don’t want to keep driving it overheating, of course, that’s why we just had it in the shop… A different shop, by the way, than the first two water pumps installer. They said they changed the thermostat, so it should just be days old… but, I too am pretty upset they didn’t discover the fans not working, especially since I asked them to check! So not as confident as I could be about the work they’ve done. It didn’t start overheating until I’d had it back about two days.
Coolant is filled up with 50/50 (my mix, but I do test it occasionally to be sure…) every few days (this was before the shop). Since getting it back (6 days ago) I’ve topped it off twice (didn’t take as much as before) and today the radiator was near full with the overflow empty, I filled both before I bled the air. It may be being forced out, I’ve seen some coolant below the tank (but I occasionally spill, so I’m not 100% that it wasn’t me). Think it’s just the mystery leak (I suspect it’s toward the back of the engine… any clues?) or is there another reason the engine would heat up so fast? Water pump, maybe? (just kidding… I hope!) Thanks again all!

There should be no pressure in the radiator when it’s stone cold…Like overnight…How much coolant have you added since the shop gave the car back to you?? Have you ever found the overflow tank full but the radiator not full?

Really, the only reason an engine should overheat very quickly (say inside of 5 minutes) from a stone cold start would be if it was very low on coolant or the thermostat was an issue; for whatever reason.

Cooling fan operation is not an issue in the first 5 minutes unless the A/C compressor was running, which it will do when the mode control is on DEF.

If the engine starts to overheat again pop the hood and touch the top radiator hose that runs from the thermostat housing to the radiator. If it feels cool or lukewarm then there just about has to be a T-stat problem.
I sure don’t buy that 3 bad water pumps BS explanation you were given though.

Has Anybody Suggested Or Checked The Cylinder Head / Cylinder Head Gasket ? Unfortunately, Most Of These Dramas End With A Bad Head Gasket In The Final Act.

A prime suspect is a car that is 16 model-years old with 160,000 miles on it. You’re right that it can’t continue to be operated. You’ll destroy it. A bad head gasket will allow the engine to consume coolant, put pressurized air in the cooling system, force coolant out, and make the temperature gauge and heater work intermittently. If it’s not bad now, it soon will be.

Get it to a competent shop / mechanic where it should be fairly easily diagnosed. This is not rocket science for a competent mechanic presented with the vehicle.