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Drove the car for about 10 mins and parked it, heard a boiling noise and decided to open the hood, one of the caps is boiling and the left side of the engine has a leak, I’m not sure if I need to take it for a rebuild so need someone more knowledgeable to identify what the problems are, thank you! Here are pics/videos
Come on...... just replace the cap. Obviously coolant isn't supposed to be coming out past the latch 😑😑😑
Originally Posted by DaleClark
Those Lev-R-Vent caps are garbage. Get an OEM cap and don't worry about it again.
Dale
Planning on doing it today, there’s a 16psi one from autozone would that be ok, I think the oem ones are sold out. I also actually asked the guy that rebuilt the engine, not the previous owner about it, he said it’s constantly building pressure because there’s no coolant overflow tank
"Engine fire" is a bit strong, but it's just a world of bad all the way around.
I wouldn't drive the car until this is sorted out. I also wonder if something this basic was done poorly what else was done poorly. This is SUPER basic.
"Engine fire" is a bit strong, but it's just a world of bad all the way around.
I wouldn't drive the car until this is sorted out. I also wonder if something this basic was done poorly what else was done poorly. This is SUPER basic.
Dale
Wasn't Mazda's radiator cap recall # 94V094000 triggered by engine fires that occurred when over-pressurized coolant systems leaked and coolant ran onto the hot turbos or exhaust?.
It was mainly from coolant leaking, then drying, then that becoming a hazard. Of course this is also on stock FD's running 107 deg. C water temps with a nuclear hot pre-cat, a bone stock FD was just insane how hot they were under the hood. The engine fire thing was handled with the fuel line recall, leaky fuel WILL cause a fire, that was the main cause of early fires.
Hold on, you don't have an overflow tank? Do you have an AST?
This is cooling system 101, you need to either have an AST or proper AST delete.
If you have a sealed system, the system will build infinite pressure until it finds a way out. This is Real Bad.
Read up on this and find what you need to do. Also slap whatever idiot built the car like this.
Dale
Originally Posted by Retserof
If it doesn't have an overflow tank, it will leak coolant or blow a hose once the engine warms up enough, so be prepared for an engine fire.
Originally Posted by DaleClark
"Engine fire" is a bit strong, but it's just a world of bad all the way around.
I wouldn't drive the car until this is sorted out. I also wonder if something this basic was done poorly what else was done poorly. This is SUPER basic.
Dale
Yeah I won’t drive it until I get it sorted out, car just keeps popping up w problems, should’ve had it checked out before buying but too late now. The builder just told me to buy the coolant overflow tank, it does have AST according to him, I think the AST is where the boiling cap is on?
The pressure relief cap I saw in your pictures was on the filler neck, not the AST. I didn't see an AST anywhere in your pictures, but they didn't cover all of the engine bay.
When the car is modified correctly to eliminate the stock AST, the pressure relief cap is relocated from the AST to the filler neck, which in turn is either modified or replaced with a different neck to have an overflow bung just below the cap and a hose from the bung running to the overflow tank.
Stock filler neck and cap (no pressure relief). The filler neck is the older 2-piece design. Yours is a 1-piece. The small hose runs to the AST.
Aftermarket AST with standard pressure relief cap. The hose by the cap is pressure relief and runs to the overflow tank.
The pressure relief cap I saw in your pictures was on the filler neck, not the AST. I didn't see an AST anywhere in your pictures, but they didn't cover all of the engine bay.
When the car is modified correctly to eliminate the stock AST, the pressure relief cap is relocated from the AST to the filler neck, which in turn is either modified or replaced with a different neck to have an overflow bung just below the cap and a hose from the bung running to the overflow tank.
Stock filler neck and cap (no pressure relief). The filler neck is the older 2-piece design. Yours is a 1-piece. The small hose runs to the AST.
Aftermarket AST with standard pressure relief cap. The hose by the cap is pressure relief and runs to the overflow tank.
Thank you for the pics and info! Currently at school so I can’t take a close look right now but here are the pics of the engine bay
Yessir, definitely will order one, thank you very much! I’m gonna find out where the filler neck hose runs to when I get the chance, and that’s gonna be the ast?
Is this not the same hose running from the ast delete to the overflow? If so I would think he needs a new cap. Obviously all the connections should be checked.
OK, I see the overflow tank and bits of hoses that might be the same hose. So maybe the AST was eliminated correctly and the problem is just a bad pressure relief cap after all. But it looks like it has a stock filler neck, not one that has been modified for AST elimination.
For that to work, a "new" nipple on the filler neck must be located so it vents the pressure cap. The stock nipple location won't do that. With the first (2-piece) version of the filler neck like mine, you could replace the top piece with a plastic nippled one from and FC, or get a metal one like this from Banzai http://www.banzai-racing.com/store/93+_rx-7_AST.htmlBillet Aluminum Filler Neck and then cap the original nipple that ran to the AST. With the second (one-piece) version of the filler neck, you need to cap the original nipple and drill and tap in a new one higher up on the neck so it properly vents the pressure cap when it passes coolant between the lower and upper cap seals. That's why I suggested posting a picture of the inside of the car's filler neck -- to see if it has a new nipple where it needs to be.
Is this not the same hose running from the ast delete to the overflow? If so I would think he needs a new cap. Obviously all the connections should be checked.
Originally Posted by Retserof
OK, I see the overflow tank and bits of hoses that might be the same hose. So maybe the AST was eliminated correctly and the problem is just a bad pressure relief cap after all. But it looks like it has a stock filler neck, not one that has been modified for AST elimination.
For that to work, a "new" nipple on the filler neck must be located so it vents the pressure cap. The stock nipple location won't do that. With the first (2-piece) version of the filler neck like mine, you could replace the top piece with a plastic nippled one from and FC, or get a metal one like this from Banzai Air Separation Tank (AST) (93+ RX-7)Billet Aluminum Filler Neck and then cap the original nipple that ran to the AST. With the second (one-piece) version of the filler neck, you need to cap the original nipple and drill and tap in a new one higher up on the neck so it properly vents the pressure cap when it passes coolant between the lower and upper cap seals. That's why I suggested posting a picture of the inside of the car's filler neck -- to see if it has a new nipple where it needs to be.
Thank you very much for y’all’s help, I’m gonna get back to you guys tomorrow once I get back from work to see if the hose goes from the filler neck to the overflow tank and the builder did say it has AST, maybe it’s hidden in there somewhere since one of the relay boxes, the TNS box was just jammed right in between the radiator and the inter cooler. If it doesn’t have AST then I will go ahead and open the filler neck to see if the nipple is in the right place
Question about the AST, if it my car doesn’t have an AST can I just buy an aftermarket one and connect it instead of modifying the filler neck for a ast delete or is it necessary for my setup to just modify the filler neck to connect a nipple to the overflow tank?
10-10-21, 11:30 PM
