3AC Pukes coolant. No heat. Temperature Fluctuates.

[Scout23]

I have a 1986 Toyota Tercel Wagon with a 3AC with approximately 166,000 miles. When I purchased it I was told that the head had been redone and new head gasket water pump etc had been replaced. The car was involved in an accident and it had set for awhile. I've replaced the thermostat once with a cheap one from Orilley's probably only 600 miles or so ago. It doesn't smoke from the exhaust. There isn't any water in the oil. It looks like there may have been oil in the water at some time but I don't think there is currently.

The engine runs great. Misses slightly at idle but nothing abnormal for an older rig. My problem is it won't keep coolant in the radiator. I've been filling it every few days and have an overflow bottle hooked up so I can just pour the coolant back in. Yesterday I decided to start the vehicle after filling the radiator with the cap off and when I did it shot coolant everywhere for the few seconds I had the engine running. Can anyone tell me if this a head gasket problem or thermostat problem? Should I replace the thermostat again with a more expensive model from NAPA. I also have very little heat inside to defrost the windows and stay warm in the winter. The last few days I've been driving it home it will maintain normal temperature then start to climb and then peg the guage and then start to come back down (this all in only a few miles). By that time I am home but have decided I better not keep driving it until I figure out what is wrong. I'd like to keep it running for another year or so and it's a great rig. Any help is appreciated. Thanks in advance and Happy Holidays.

[Petros]

Welcome to the list!

The problems you describe could very well be the T-stat, I have had bad luck with the cheap ones and do not buy them any more. some are junk right out of the box, I have also found that for some reason is the car sits for six months or more without running, that for some reason the T-stat goes bad as well. Both Autozone and Napa sell a premium quality t-state (about $16) that is pretty good. Also the factory Toyota thermostat (usually about $20) is one of the best available, lasts way longer than the cheap ones, usually worth the extra money. You can remove the existing T-stat and do the hot water test on it to verify. But when the temp fluctuates like that it is almost always a bad t-stat, a good one should slowly open as the temp rises and than hold a stead temp just below about half way on the gauge.

It could also be the head gasket or leaky hose or heater, but what usually happens as the coolant gets consumed either out the exhaust (when leaking into a cylinder), or outside the engine, the temp slowly climbs and than goes into the red and stays there. I have found the head gasket on these engines sensitive to overheating and are easily damaged, so keep it out of the red or you might have to replace the head gasket again. If you are leaking coolant into the oil it will be frothy and have a chocolate milk shake like appearance. If you have that condition you very likely need a head gasket.

IF you do a compression check of the cylinders it might show you cylinders one and two are bad (most common place for the head gasket to fail is between cyl. one and two). If you have to replace the head gasket follow the procedure I created over in the "repair guides" section. I outline a few mods that will make the new head gasket instillation more durable. It is a big job but not as bad as many other cars, I can do a head gasket on these cars in about 4 hours or less if all goes well.

Even with a blown head gasket it should run without overheating if you can keep coolant in the radiator. I had a leaky head gasket and drove it for a year by just adding coolant at each fuel stop, it finally got so bad it would not start, leak was way too large so I had to finally fix it. Sometimes even when I knew it was bad and consuming coolant, it did not show up on the compression test. So when you do a compression test use a flash light and inspect the top of each piston through the spark plug hole (you must turn the engine over by hand and stop each the piston at the top to inspect, you can inspect one and four, and two and three as the same time). All of the piston tops should look about the same, typically with light carbon deposites. If any one or two adjoining pistons look clean and shinny, it means they have been "steam cleaned" with a coolant leak.

Good luck.

where are you located?

[Scout23]

Thanks for the info. I'm from Eastern Washington. There aren't many of these Tercels on the roads over here. I'm just using it as a gas saver until I buy a newer car. My 04 truck is to expensive to drive all the time. I think the thermostat is stuck closed or openning very little and am going to try a NAPA or Toyota one and hope that fixes the problem. I don't think the top end is getting coolant.

Thanks again.

[takza]

You can get a head gasket leak where exhaust will push into the coolant and cause it to overheat and if really bad bubble out of the rad or coolant tank. TEST: start it cold with the rad cap off.....look for bubbles in the coolant at the cap.

[splatterdog]

You describe symptoms that might or might not suggest blown head gasket. Does the overflow tank smell like a tail pipe? Pull the plugs, got one or two that are much cleaner than the others?(tops of piston's will match) Not good. Might have had water in the oil but not currently? Was that from an oil change or did it go away on it's own? Where exactly is the coolant going? Cap off running fill and gush done hot or cold?

Checking the stat would be worthwhile. Backwards maybe? It might be doable with a cheap stat. While you are checking it, get an OE stat. They are worth the extra $. Pretty sure Kuzeh is Toy's OE supplier, as well as other asian brands.http://www.partsgeek.com/catalog/1985/t ... ostat.html Don't forget to position the jiggle valve at the highest point.

I see no mention of checking/replacing the cap. Many a guy has chased his tail over such a simple device.

You gotta figure this out, even if only for a years worth of use. That car is just broken in! My 84 had that many miles when I got it, and made it 10 years/120k. Still plenty alive but with terminal body cancer.

Good luck!

[Scout23]

The overflow tank doesn't smell like exhaust but since I've had the vehicle seems haven't been able to keep coolant in it. Normally I will just fill it up and put the cap on and after a few days it will puke the coolant back into the overflow. I changed out the thermostat and that seemed to maintain proper temperature about half on the guage. The problem started again just a few days ago only worse fluctuations. It started maxing out the temp guage and it's 20 degrees out. I decided to park it before I do some real damage. The next morning I went out and added coolant. Started it with the cap off and it was shooting coolant everywhere out the filler of the radiator. Big mess and it only ran for a few seconds. So cleaned that up and left it then the next day started it but only let it run for a minute and it seemed like it wasn't getting water to the top end. Tommorrow I will see if I can pick up a quality thermostat and replace it and see how that goes.
As for the oil it has always been fine but when I first got the vehicle there was a little bit of foam in the radiator. The vehicle itself is no looker (most people I know would be to good to drive it). It has an off color hood. The grill is held on with zip ties and has a broken windshield but it's a good daily driver around town. The story I was told was the previous owner hit a dear or animal and it had sat for some time before being rebuilt and that is what looks like happened. New water pump, belts, hoses, plug wires, exhaust and head work. I appreciate everyone's help. I'd like to keep my gas saver running another year or two as it helps save a few extra dollars and miles on my truck and I can drive it and not worry about leaving it in the parking lot at Wal Mart because a minor door ding isn't going to hurt it.

[Petros]

sounds like a bad head gasket, it should not shoot coolant out the radiator right after start up. IT should run until it reaches operating temp before coolant will boil out of the filler. Something is pressurizing the system before it is even warm, that can only be the combustion chamber. Remove the spark plugs and inspect for coolant, have someone crank the engine for 10 seconds and watch if you get spray out of the number one or two cylinders, if so, you need a new head gasket. And for good measure I would put in a quality thermostat and radiator cap.

But do not panic, you can replace the head gasket in one Saturday yourself with only replacing the head gasket (about $20). You can have it running again good for cheap. Go read up on the procedure here:

https://tercel4wd.com/forums/viewtopic.php?f=7&t=6059

[splatterdog]

Yep, definitely sounds like a head gasket problem.