Hi all,
My prize baby's pressure tank hose suddenly popped off and spewed coolant (engine temp guage did not indicate overheating prior to this) while idling to cool the engine prior to shut off. Engine bay not overly hot (I always pop the hood when I get home). The car hadn't been run-hard but had been stopped/started about 3-4 times on the way home - not my common practice.

Reattached hose and CLAMPED it (didn't have a clamp there before?? Odd I never noticed). Refilled coolant. Next day it started to overheat again. Pulled over, loud popping/bubbling sounds from Radiator, then leaked coolant under the right front side (near fill tank) but only a small amount. Note: no white clouds or sweet smell from exhaust. Help, what is happening???

PS - Recent Fluidyne dual capacity racing radiator.

My friend suggested an air bubble in the cooling system caused by the sudden spray off from the popped off pressure tank hose?

Likely I will upgrade to Samco Coolant hoses but am aware there are several other smaller coolant hoses in the engine bay. I see only 2 primary Samco hoses available. Is there a complete kit for all the hoses available that would be comparable to the Samco? I've seen Stainless Steel wrapped flexible coolant hoses in catalogs. Would they be recommended? I know the RX7 takes special high temp hoses.

Or is it too late and she's a goner?

Hot up here in Montana (95-100)

 

Seals!!!

 

yessir
seals it is

 

SEALS? Do you mean the coolant seals in the engine? We talking rebuild?

I changed the fluids and flushed it over the weekend. There was no sign of oil in the coolant or coolant in the oil. There is no "white smoke" when I drive. Unfortunately, changing the coolant did not fix the problem. I'm guessing it's the thermostat. ie - when she reaches engine temp, the thermostat is not opening, thus the coolant is overheating in the engine block and not circulating through the radiator.

If that is the case, where is it located? How do you change it and is there a superior aftermarket brand that would work better to keep the engine cooler?

 

The water seals seem to be gone, save your money from the hoses and upgrades, sounds like you're gonna need a new engine

 

Even with no oil in coolant or coolant in oil and no white smoke or sweet smelling exhaust???

This seems an overly serious guess.

There a test for sure to check this or the tstat?

 

Could be the pressure cap or a number of other things other than coolant seals. Pressure caps are inexpensive and easy enough to try. The t-stat is located under the fill cap on top of the water pump. Again, unlikely it's the t-stat but it's failry inexpensive and easy enough to try. Other than that do a search for coolant seal diagnosis and check for that. Radiator shops can check the coolant for exhaust gasses. That's a fairly certain check. Beware that the root cause of the overheating in the first place could of led to a seal failure and if a rebuild is performed the root cause needs to be addressed or the situation will repeat itself.

You will very rarely see oil and water mixed. Unlike a head gasket the two systems in a rotary are fairly distant and do not easily mix. Most often when a coolant seal fails it's only the inner compression seal (it's exposed to far more heat). This results in water in the combustion chamber but not in the oil pan.

 

how many miles are on the motor? if its near 100k i would suggest the motor is gone.

 

Engine has 58,000. Apparently when you store it over the winter, you need to start it 1-2 times a week or the seals go bad... Ok, 2 winters of storage so that would be my guess why it could be the seals. Ain't 20/20 hindsight wonderful?

Now then, THE test to do to determine if this is the problem for sure? I ain't loaded with cash.

 

buy the seals dont eat your coconut

 

C Ludwig has some good pointers. Sounds like you may have some air pockets in the cooling system, since it was changed recently.

Did you do the "burping" method to clear out the air pockets? I think there is a thread here that explains it, if not send me a PM. Do this first, then if problems exists, change the pressure cap and T-Stat.

No white smoke is a good sign, but I won't drive it too far until you fixed the overheating problem. An engine rebuild is expensive, even more if you don't plan to remove and install the engine.

I did it three times and don't look forward in that type of exercise.

 

same thing here...
its -18C here today (calgary, alberta, canada) ( dec3rd)...
my ''winter car'' (93 MX-6) did not start this morning... so i was forced to get my FD to work... it is snowing... it is cold!!!
the car has arrived from japan about a week ago... its bone-stock. I have not done anything to it yet except for adding some oil. So it started ok, i warmed it up for about 5-10 mins. Half way to work (about 5 mins into the drive) i noticed that the temp indicator is high... i know from all the material i've read on rx7's that even if the gage is high a little bit you should pull over and let it cool down immediately.. i had no chance of doing that for i was goin on highway with no shoulders to pull over on... i had to drive it at least 3 or 4 mins more... the further i went the higher the tempterature went... as soon as i got a chance i pulled over and popped the hood.... that pressure hose has popped off cuz there is no clamp on it (and i dont know when it has popped off...when the car was already over-heated or that was the reason?) ... some coolant was still in the engine... "some" stans for very little... the beep and light for coolant was going off... i let the car cool down for a few minutes.. and then i drove it about 200m and i was at my destination... i know i should not have driven it after....
at work i have found out that in japan they use a very lean mixture of cooland and its mostly water there... (thats why the dipstick had ice on it when i checked it... even while overheating).. the car was steaming and started to have smoke coming out from under the hood. my guess on observation was that thats that water/coolant steaming and burning off the hot block.... but its just a guess.. the car starts fine.. seems to work ok... at the end of today its going for a coolant flush... and we will see what happens,..... ?
unfortunately i know that at this point i have to keep rebuilt in mind but being lil short on cash i dont want to thing that just yet... i've read a few suggestions here on some smaller things... if anybody has any comment i'd greatly appreciate it...
and also some words of encouragement would be nice like, ''if it overheats it doesnt necessarily need to be F@#$ed and rebuilt." .. something along those lines...

 

well... so the coolant flush was done ... the engine seems to be working fine to the best of my observations...
anybody have tips on what i should be looking out for?

 

If you have a bad coolant seal, you'll have lots of white smoke out the exhaust, the car will be hard to start, and you'll be filling up (and overfilling) your overflow tank, resulting in puddles of coolant on the front passenger side of the car once you shut it down.

Whoever didn't clamp that coolant hose may have fried your motor

 

YUP! time to spend more money, ROTARYS< LOVEM & HATEM

 

It def sounds like the coolant seals. Your gona need a new motor. No matter what. Theres a vid on Youtube of a guy showing what happens when you run boost in your car before it warms up, same thing thats happening to you with the overheating and smoke. Your seals are gone, thats the crappy part about turbos n rotaries.

 

Is there ever an ending to this thread? What happened and what was the root case.?