Okay, Mazda reman with 28k on it. Koyo rad and coolant hoses are about a year old and I am running 50/50 coolant and distilled water.

I took off rowing through the gears to redline down the access road today and basically the upper hose from the coolant reservoir to the thermostat housing busted around the clamp at the thermostat housing.

Number 14 here.

http://www.flickr.com/photos/9krpmrx8/5671540362/

The factory hose was unavailable anywhere so I had to use store bought coolant hose of the same diameters. The factory hose had a brass restrict-or in it which I thought was weird but I put it in the new hose and reinstalled everything. There are no leaks anywhere.

I added distilled water (no coolant at the office where I was fixing this) and drove home. Driving home I was averaging temps of about 210F. This is about 20F higher than what I see normally at these temps with the Cobb activating the fans earlier than stock.

I get home and at idle after a few minutes with the fan on and the temps are staying at 210-212F.

I turn the heat on and nothing, it's cool air.

I rev the motor and stay at 3,000RPMS and immediately the heat turns hot and temps drop 20 degrees.

As soon as I let off, the heat turns cool and temps rise back up.

In the morning I will do a drain and fill and bleed the system properly but what do you guys think it could be? I let it run with the cap off for a while thinking most air would escape the system that way but do you think an air bubble could cause these symptoms?

 

odd - did you have to add water when you got home ?

 

Nope, level was right at full. No leaks anywhere inside the car or anything either.

 

Isn't the brass restrict in the hose had something to do with some kind of noise. There was a thread about this long time ago and that brass part was subsequently revised to a different size to resolve that noise.

 

the restrictor is to stop too much water bypassing through the header tank .

 

Ah thanks for enlightening me Brettus, couldnt remember exactly what it was for (been a long time since).

 

I guess I am going to replace the thermostat for GP. I am going to have to go with a store bought item for now and order a Mazmart Thermostat.

Does anyone have any experience with store bought thermostats? I searched for reviews but couldn't really find anything.

 

they are just as good as stock, i have one in my 8 and i haven't had a problem with it overheating. make sure the dirt bags include the gasket, they almost screwed me over by not including it.

 

Yeah it appears they vary in price by 10-15 bucks. I don't usually use car Quest but they have one with the gasket for $20.00. I'll be back!

 

Okay guys, swapped out the old thermostat (should have been new with engine 28k ago), flushed and bled the fluid (done 10,000 miles ago) and now everything is working fine so the thermostat had to have been bad.

Changing it without the air pump and tube to the exhaust manifold made it a lot easier but still kind of a pain to remove the alternator bracket.

 

tell me about it! i almost snapped that dam tube in half, on how pissed i was lol

 

It's also one of the cures for MIAC(for the majority of people), so Yiksing was right in a sense. Keep that in mind going forward 9krpmrx8 if you develop Marbles in a can at high rpm's.

 

I put the restrict or in the new hose, I figured it was there for a reason so I cut it out and reused it. I drove around all afternoon and night, temps are back to normal. Wierd that the old thermostat failed closed, so much for failing open.

 

I believe all Mazda t'stats fail close.
I almost blew up my '95 626 V6 several times when the t'stat failed.
Recommend the Mazmart t'stat that fails open and it is fully open at 190 degrees.
Mazmart wp is a nice item too.

 

Not that it matters, but daughters 3 failed open.
At least it was an super easy(and cheap) fix on that car.

 

Must have been, I did a coolant flush yesterday and I'm actually running a wee bit cooler than I was(albeit not much), so it was time.
I was going to put on my AP hoses, but said..screw that....didn't feel like taking the whole car apart yesterday, so I just drained and flushed using the engine drain and no real burping other than leaving the cap off and bleeding it that way. Seemed to be okay as I did have it jacked up in the front and the coolant bottle was about the highest point in the system at that time.

 

Jacking up the front end is the way to go.
The mechanics at the local dealership put the front wheels on the lift and raise the front end a coiuple feet. They also disconnect the coolant hose to the TB and remove the remainder of the air in the system.

 

Yeah I burped mine through the TB as well just to make sure.

 

Okay so weird issue today, it was about 96F cruising to my bosses house driving fairly aggressive through the back roads and all of the sudden my coolant temps creep up to 212-217F. New radiator (less than year), new thermostat, fresh coolant (old coolant looked great), all new hoses, and I checked and my fans are working. I burped the system so any thoughts on why it climbed? On the way home it was back to normal but it started to rain so the temps dropped quite a bit.

I will keep an eye on things but I am thinking maybe I need to flush it, I may have put too much straight coolant and not enough distilled water.

 

You've had enough cooling issues that you should get a test kit for combustion products in the water.

Maybe the engine water seals are allowing pressure into the cooling system, and impeding flow.

I drove my RX3 like that for over a year, and it was mostly a seep into the chambers after cool down, but it seemed that it could send a bubble into the cooling if driven hard.

 

I hope that's not it. I haven't had any smoke or anything from the exhaust and the coolant I removed into a five gallon bucket looked good. I even removed the bolt on the block to make sure I got it all out.

If this reman is failing after only 28k I am gonna be pissed considering all I have done to protect it. When the coolant temp was high I did notice my oil temps were slighty above normal at cruise at just above 200F. Maybe the coolant temps would have been higher if I didn't have such a big oil cooler.

 

Yeah, these issues can be annoying, but didn't you see my guy already crying for you?

I bought a new 85 Cougar 2.3 turbo, drove to the Mc donald observatory (6700 ft), and the over flow steamed some which I thought odd since I the car was new.

I'm really gentle on cars, and it was about 6 years later while flogging it at 110mph that a small hose came off and sprayed all the water out before I could stop.

Had a head job later to fix bad valves, and miss; ran like a charm after that.

So I drove all those years with a crappy factory head torque or gasket, and it took years for it to dawn on me why.

When the pressure was on the combustion pressure would push by the head gasket, but most other times run fine.

Good luck, and maybe another water burp!

 

I did see quite a bit of grayish smoke on your Texas 8 run.

 

Hey 9k your running to much coolant as well. Here in Texas you need to run 30/70 coolant/water. I know I went over this someplace before but here is the just of it. 30/70 will protect you to -8degrees and 25/75 will protect you to 0 degrees. The coldest Texas has ever seen.

Secondly Coolant is 20 times heavier than water with only 1/3rd the ability to transfer and carry heat. By running more water you can improve your engines ability to transfer more heat out. If you switch from 50/50 to 25/75 you have improved the coolants ability to carry heat by 50%. If you want to I can go over the thermal dynamics with you some other time. Just know that your not giving your cooling system all that it is capable of.

 

why not just run water and redlines water wetter.