Coolant/Timing Belt/Heater Core/Coolant 1997 Toyota Camry

The car is an automatic 1997 2.2 liter Toyota Camry with ~134,000 miles. It was purchased recently from a friend and I have driven it very little. Recently I noticed a small vibrating noise coming from under the hood and a burning smell that seemed to be located near the front driver side wheel. The coolant was almost empty. I replaced the coolant and noticed some fumes coming from the vents (the ac/heater was off) which quickly fogged up the windows. The windows have always fogged up more than usual and I had thoroughly cleaned them with automotive glass cleaner because I thought this was due to the previous owner being a smoker. After driving less than 20 miles the coolant receptacle was empty (though the radiator seemed to be full to the brim).

In any case, I went to a mechanic and he told me the timing belt needed to be changed as this was causing the vibrating noise. He also said that the heater core is probably leaking (thought it would need to be inspected) and should be changed, and this is what is causing the fumes in the car. He said the burning smell is probably due to the recently changed catalytic converter getting “broken in”.

Could wear on the timing belt (and associated parts like the water pump) be causing the burning smell and fumes (rather than a leak in the heater core)? Is it standard to change the water pump when the timing belt is changed? Why would the coolant be disappearing so rapidly? How much should I expect to pay to change the heater core? Any other advice?

Thank you very much!

The timing belt and “vibration” seems a bit strange, possible I guess but unusual. Since changing a timing belt is pretty extensive job, I’d get another opinion on this one. Perhaps the mechanic meant the “serpentine belt”?

The fogging on the interior windows is consistent with a leaking heater core.

The smell could be from the coolant leak, something leaking onto the exhaust manifold, or even be something related to the belt that is vibrating. Again another opinion from a different mechanic is my recommendation.

I’d even consider getting a Toyota service department opinion on these problems. Might as well see if the dealer’s prices are close to the other mechanics.

Thanks a lot, this is very helpful. I will get another opinion from a different mechanic. The prices indicated by the Toyota dealership ($550 for a timing belt change and $650 for the heater core) are comparable as well.

It’s bad for your health to breathe in coolant fumes, so I’d suggest getting the heater core fixed pretty soon.

I don’t know about your car specifically, but be aware there’s often a lot of labor involved in getting to the heater core, so don’t be surprised if the price is high for that.

You can change some hose arangements around under the hood to bypass the heater core. If you still lose coolant it is not the heater core. You may have a blown head gasket, that would cause a vibration by loss of compression and could lose coolant into the cumbustion chamber or out the side of the head gasket. Need more info on the vibration, do you feel it driving, sitting still, accellerating? A new cat will have an odd odor, it could be a brake caliper that is hung up. Again need more info when the odor occurs. I agree with UncleTurbo, a vibration from the timing belt would be extremely rare.

Thank you. I guess its not as much a vibration as much as it is a thin rattling sound. Its there especially when accelerating, but also when the car is parked and in neutral and the engine is running. Its more on the passenger side.

The odor occurs after driving the car for a short while but not immediately.

A thin rattle sound cound be a loose heat shield. If the cat was replaced it is very possible. The timing belt is also on the passenger side of the car too. It might be something in the timing belt area making the noise such as a bad bearing in the tensioner. The timing belt is one thing you should never neglect on this car. If the belt breaks you are going to be in for some very costly repairs. When the belt gets replaced your should replace the water pump and the timing belt tensioner. When you take you car for a drive and smell the burning smell see if the driver side wheel , not tire, is hot compaired to the other wheels. If it is your brake is not releasing properly.

I agree that it sounds like the heater core needs changing and if your timing belt has not been changed it should be. You should be on your third belt by now (see 2nd link below).The serpentine belt is part of the job.

And the rattle should be easy to find just by listening.

But I do want to point out that if you’ve just had your cat converter replaced you will smell a burning smeall as the machining oils cook off. The cat converter on this engine is a part of the exhaust manifold, and it gets hot…over 800F. I can tell you from experience that a burning smell is normal after replacing teh cat converter on this setup. See the 1st link below to see where the conveter is.

The fogged windows are classic heater core symptoms. If your timing belt nas never been changed, it is way overdue and the tensioner (probably the source of the noise) and water pump should be replaced at the same time. This adds almost nothing to the labor which is most of the cost of this job.
If the timing belt breaks before you change it you will destroy the engine.

Thank you very much UncleTurbo nyeguys the same mountainbike and oldtimer 11. Very helpful. It sounds like both the timing belt and heater core require changing, so I’m going to go ahead and get those repairs.

I also support Oldtimer’s suggestion to have the water pump changed too. The pump is driven by the timing belt, and with the amount of mileage yours has it’s prudent to do both, as well as the belt tensioner if it’s grown weak. Most of the belt cost is labor, and if the pump blows the entire job will have to be done all over again.

Acording to Gates, this is NOT an interference engine so no catastrophic engine damage will happen if/when the timing belt breaks. It may be inconvenient but not lethal to your engine.

Before changing a heater core, I would recommend checking the heater hoses where they attach to the core just to make sure that they are not leaking and the coolant following the core leads into the cabin. I’m not saying that’s it, but at $650 to change the core and $0 for checking first, I’d check.

True, Casper, but it still should be changed. One does not want the car suddenly shutting down in the middle of the Sumner Tunnel (Boston) or the Garden Parkway (NJ).

Thanks keith. I’ll check the heater hoses before changing the heater core.