Originally Posted by drock001 (Post 11059120)

my coolant over flow on my 88 13b non turbo has been boiling and the car has been overheating, iv replaced the whole cooling system, radiator , water pump, thermostat, and head gasket, the car finally stopped overheating but the reservoir is still boiling and overflowing does anyone know what could be causing this?

Originally Posted by drock001 (Post 11059120)

my coolant over flow on my 88 13b non turbo has been boiling and the car has been overheating, iv replaced the whole cooling system, radiator , water pump, thermostat, and head gasket, the car finally stopped overheating but the reservoir is still boiling and overflowing does anyone know what could be causing this?

Originally Posted by Einheri (Post 11059679)

Usually a bad radiator cap, or head gasket. Check to make sure that your coolant isn't somehow getting large amounts of air mixed in with it, which will facilitate the boiling. If you already checked the head gasket, then try the radiator cap.

Originally Posted by funkjaw (Post 11060290)

Sounds like possible coolant seal failure in the engine, evident by the overflowing coolant reservoir.

Originally Posted by Eduardo Santos (Post 11059996)

I'm sorry, but... Head gasket on a rotary engine? I'm no expert in rotary engines, but I don't think that's possible, simply because rotary engines don't have such a thing as a head, let alone a head gasket...

Anyway, the radiator cap thing seems to be a valid point to check, in my point of view...
Other things you can check:
-if the cooling system has air in it, then it needs to be bled.
-Coolant seals on the engine may be failing. If that's the case, then... :badrebuild:

Originally Posted by flaco (Post 11061609)

oo ok. well what brand was the head gasket you put on it ?? did you get it at the local autoparts ?? cause i heard the aftermarket head gaskets are bad.

Originally Posted by marclong (Post 11061728)

Bent pushrod maybe?

Originally Posted by Einheri (Post 11062216)

I thought trolling was for the generation specific sub-forums.

Originally Posted by Karack (Post 11067269)

generally it's not the coolant boiling but air pushing into the overflow like blowing through a straw into the reservoir.

what does this mean? bad head gasket.

oops, i meant bad coolant seals.

Originally Posted by Einheri (Post 11067909)

......I still had a valid point about the coolant cap, regardless. If there is air getting in your coolant, it will boil or bubble and over flow. Burp out the air

Originally Posted by Sgtblue (Post 10464566)

A coolant seal failure is a common problem....at least in the FDs of which I'm familiar. IMO it's the price for forced induction. Boost is power. More power= more heat= more stress. NA rotarys have the problem, but AFAIK, not nearly as soon as the FDs.

Still, before doing anything, make sure you have a failed seal. Besides the 'Champagne test" these are all the symtoms I can think of... but no single symtom by itself is confirmation. Many symtoms could be from other causes. However the more symtoms/conditions you have in combination, the more likely it is a coolant seal failure.........

*Stumbling idle on cold start-up that clears up quickly. The combustion chamber is fouled with coolant. As soon as it's purged or burned up, your car will run fine until the next cold start.
*Slightly sweet exhaust smell, especially on start-up. See above. Coolant is being burned and it has a distinctive smell.
*"White smoke" (steam) on cold start-up even in warm/hot weather. See above.
*A coolant over-flow tank that is over-flowing. This will usually result in a puddle under the car near the right front...the area of the over-flow tank. When coolant gets hot it expands and that's what the overflow tank is for. But with a failed seal the nature vacuum that forms and pulls that coolant back out as the engine cools down is lost. That leaves that coolant stranded in the tank and eventually it overflows.
*Coolant loss that isn't explained by a puddle on your garage floor. It's being consumed by the engine and going out the exhaust.
*Spiking temps that seemingly recover on their own almost as quickly. Air pockets in the cooling system allow steam to form. That will cause temp spiking. This is different than a rising temp just after a period of hard boost. It can happen as your steadily cruising down the highway.
*Boiling sounds after shut down even shortly after properly "burping" the system. See above.
*Failed coolant system pressure test.
*Failed test of coolant for hydrocarbons.
*Unusually clean plugs, or wet plugs if you pull them right away after starting the car. (Sometimes you can even smell the coolant)
*One or more episodes of serious overheating in the car's history regardless of miles. (from what I've read, 115 C./240 F. seems to be the critical number for OEM seals to begin to degrade)
*An otherwise well maintained and cared-for FD approaching 100K miles or so.

As for a bandaid, some have used one of the many "Stop-Leak" coolant additives to give them a bit more time but use at your own risk. While it's not anything that will leave you on the side of the road, a failed coolant seal can easily lead to errosion/rust/pitting of the coolant seal grooves in the irons. That can cause a junk iron and make the inevitiable rebuild more expensive.