turbo24u

Hello my name is Chris and I have an 88 TII which lately has done more sitting then driving. I did a search of the site and came up with some good ideas and things to try out to get to the bottom of my problem which I will explain in the best detail possible below. Well here it goes, sit back, grab some popcorn and enjoy my experience with owning this car for some time now.



I bought the car about 7 months ago with 133,000 miles on it and drove it until the alternator belt snapped. Previous ownder said it would soon need replacing. So I replaced it and drove the car for a few months. I noticed when the car would be sitting there idling that sometimes coolant would push out the overflow bottle. Now this would happen everyone and awhile and not nearly as often as it does now. I decided to change the thermostat thinking that may be the problem. Unfortunetly the thermostat housing bolts were rusted on tightly and both bolts ended up being snapped after trying to get them out. After attempting to drill out the remains of the bolts and taking a chunk out of the water pump housing where the two t-stat bolts go I decided to let the professionals handle it. I unbolted the water pump housing and sent it out to be welded, drilled and tapped and they did an excellent job repairing it. I searched for the gasket that goes between the engine block and the water pump housing but apparently they don't exist anymore. I went to Auto Zone and bought the make a gasket stuff which is already a gasket which just needs trimmed down to fit. I used the same type of gasket for the water pump gasket. I installed a new 180 degree t-stat and bolted everything back together and started her up. She ran great with no problems for a day until the new v belt snapped again and the engine did overheat for a decent amount of time which in the process blew a small hole in the hose labeled as the heater hose in the FSM. I pulled off the hose which is right by the sparkplugs and saw the hole was close to the engine end of the hose. Instead of entirely pulling the hose off I decided I could probably cut the bad end off the hose and re hook it back to the flange coming out the engine down by the spark plugs. It was a tight fit but it did reach. I didn't notice the hose being pinched or kinked anywhere and from what I could see of the hose it looked like it was still in good condition despite the prior overheating.



Next to figure out why the v belt keeps breaking. I noticed that the spacer for the alternator was in the wrong spot instead of being located to the rear like it should be. I relocated the spacer, replaced the belt and refilled the coolant. Car ran great for about 3 days without a problem. On the 4th day I was doing a good bit of driving and the add coolant light came on randomly for the entire trip although the car never overheated. When I got home I noticed that the coolant bottle overflow was almost completely full. I went out and bought a new Stant Radiator cap good to 13lbs and installed it. I let the car sit in the driveway just idling for about 45 minutes and when I came back out the temp gauge was just a little bit above the "C" and it stayed there. I turned on the cars heater and it was blowing hot air just like it should. I took the car out for a pretty decent period with the heat working constantly and the temp gauge staying around the "C" for the entire trip. Once I got back home I shut the car off and let it cool down. I came back out and noticed that the coolant overflow bottle had filled up slightly since I last drove it (about 1 1/2 or so above the full line.) I restarted the now cold engine and basically repeated the same process, let it idle for a good bit and then drove it up and down the street. Temp gauge was where it should be the entire time, heat was working and when I parked the coolant overflow bottle had not increased or decreased any in fluid.



Great I thought, alls it needed was a radiator cap. Not true. The next day I went to drive the car to work and I went out and started it so it could warm up. I turned the heater on so the car would be nice and warm when I came back out and I left the car to idle for about 20 minutes. When I came back out much to my horror the temp gauge was alittle above the half way mark (closests to the "H") and the air coming out of the cars heater vents wasn't warm at all. I noticed a small stream of coolant coming out the hose from the coolant overflow bottle which was now completely full and flowing onto the ground. Some bubbles could be seen inside the overflow bottle. This is now what the car does at random although it seems to not want to go to work as that is when it happens the most. For general information the temp outside was around 30 degrees on most occassions so I doubt that has anything to do with it.



I have tried to rent a pressure tester to check for any leaks but apparently noone rents them around here and they are around $200 to purchase at Auto Zone. A little more than I would like to spend since I will probably only use it once. So I am still looking for one. Anyway we I am asked I did bleed the system for air when I was filling it so as far as I know there shouldn't be any air in the system but in case I did something wrong when bleeding it here is how I did it. I opened the coolant filler cap with the engine running and loosened (did not completely remove) the air bleeder screw on the upper radiator hose. With the engine idling I filled the coolant until I could fill it no more. I waited until the thermostat opened and coolant was flowing through the upper radiator hose and I proceeded to keep filling until it was full. I capped the filler port with the filler cap and snugly closed the air bleed screw.



After researching for some time I have come up with a few ideas to what may be wrong, namely coolant seal failure on the intake side. When the car is running at no time is smoke seen coming from the exhaust which according to what I read should indicate an exhaust side coolant seal failure. I do remember seeing bubbles in the coolant overflow bottle but don't remember seeing them in the coolant filler port as I seen some rx-7's on Youtube experiencing.



So if it really was a coolant seal would this be affecting my heat, allowing it to not work sometimes?

If it was a coolant seal failure, would it be possible for the car to run fine one day and than the next started spewing coolant out the overflow bottle? Whatever the problem is, it seems to be intermittant as the car ran fine for two days before acting up. The problem with the heat not working and the a cars temp gauge rising seem to be connected as when the heat is working properly the car is also.



I hope I don't need to have the engine rebuilt. But if thats the case so be it. Any other ideas to what may be causing this intermittant problem. I did see on here several cases of coolant seal failure but none of them ever explained whether the problems caused by the failure were happening all the time or if they were intermittant such as mine is. I don't think there is a blockage of any type because if there was I wouldn't imageine this happening intermittantly, it should be happening all the time.



Overall summary of what I did and there condition:



Water pump looked old when I had it out but seemed to spin ok and the fins looked alright. T-stat I replaced with a 180 degree. Radiator cap was replaced with a Stant 13lb cap. I did bleed the air out of the coolant system when filling it by the method described above. Thermostat appears to be opening ok as coolant flow is felt through the upper radiator hose. No noticeable leaks from anywhere. I have been keeping a close eye on the heater hose and it appears to be bone dry. No smoke coming from the engine or exhaust. Engine seems to run decent except it is running a little rich and is leaking at the cat somewhat.



Thanks for any help you can give this rotary newb. This is a really informative site and I will surely be sticking around for some time to come. Thanks for taking the time to read.

turbo24u

I noticed the other day when I had the car running that both the upper and lower radiator hoses had pressure in them. The heater hose was warm but the heat in the car did not work. I had the car running for about 15 minutes when the car started smoking out of the radiator. and I shut it off. No idea what that may have been.

Baldy

Did you replace the thermostat with a Mazda t-stat?

turbo24u

No it was replaced with a aftermarket t-stat

PO gave it to me with some additional parts when I bought the car. I noticed the t-stat doesn't have a jiggle pin but it was brand new in the box and wrapper.