Nelson Rebelo

Hi

Just bought a 1990 rx7 with 13b engine non-turbo. (I'm New to rotary)
Seller told me it was a swap.

I noticed a small coolant leak from a pipe on the passenger side on lower block leading nowhere.

There is air that comes out and small amounts of coolant.

All other pipes (including radiator) are connected as far as I can see????

Help

Will try to post pic asap
Thanks

Aaron Cake

iTrader: (1)

Sounds a bit like the coolant pipe that connects to the nipple on the rear iron and feeds the BAC, thermowax, etc. Just replace the hose...But you'll likely need to remove the upper intake manifold in order to do it.

RotaryRocket88

iTrader: (7)

A picture would be helpful in this case. It sort of sounds like the connection for the split air pipe on the backside of the LIM, but this does not carry coolant. A leak from the rear iron / TB line could drip down there though.

Nelson Rebelo

Here's a pic of the pipe. Goes towards front of engine and then is cut. Goes nowhere!

Nelson Rebelo

Heres another pic from Haynes Manual which never mentions this tube??? (in Red)
Help!

RotaryRocket88

iTrader: (7)

That is the air silencer tube from the ACV relief port. There is no reason anything but air from the air pump should come out of there.

Nelson Rebelo

Thank You...where should this tube connect to since right now it goes nowhere, is that normal?

RotaryRocket88

iTrader: (7)

It normally goes to a little plastic muffler tucked behind the bumper, but you can leave it if it's missing. It's there to get rid of the "moo" sound the air pump can make when it's vented through the relief.

Nelson Rebelo

Thanks again 1 last question. If I saw some coolant coming out of there could it be a big problem. Car was flooded, and it took a good week to get it going again (lots of cranking). This never happened before?

RotaryRocket88

iTrader: (7)

Coolant could not come out of there unless you spilled it into the air pump inlet or something.

Nelson Rebelo

I kid you not. Just started engine again, the moment I rev the engine high,,, coolant gushes out Of the Air Silencer Tube. What the??????

:o(

Nelson Rebelo

Hi

Just bought a 1990 rx7 with 13b engine non-turbo. (I'm New to rotary)Coolant spitting out of the air silencer tube from the ACV relief port.

I know I just posted a thread (Mystery tube).
Well tube is no longer the mystery LOL, its the coolant coming out of it.

I know that many say its impossible, but i checked and double checked.

When engine idles normally, only air comes out.
The moment I idle high, coolant spurts out!

HELP!

Nelson

Aaron Cake

iTrader: (1)

Can you maybe post a picture or video of this happening?

Unless something truly odd has happened, coolant cannot be in the aux air system. Even if the engine is leaking internally I can't see any passage between it and the aux air system.

Are you having to add coolant to the car as it runs low?

Nelson Rebelo

http://www.youtube.com/watch?v=k4076vmp4jo


Here's a video of the leak!

RotaryRocket88

iTrader: (7)

Wow, that's a first.

I'd remove the hose from the ACV so you can get a look inside. At idle, the relief valve should actually be in the closed position. Air should not be able to exit through that port, let alone coolant. Of course coolant may have rusted the valves open for all you know. In your video, revving the engine spins the air pump faster, which apparently blows the pooled coolant out faster.

The bizarre part is that there are no coolant passages in the entire intake manifold. The nearest coolant would be inside the block behind freeze plugs in the housings, but this area is sandwiched between the LIM and block with a gasket. A leak here would drip down the side of the engine.

Another possibility I suppose would be a leak on top of the rear iron or back of the water pump housing pooling coolant on top of the engine, which could somehow be sucked in through an uncovered vacuum port. But the ACV is only connected to the intake in one location: the AAV (anti-afterburn valve, the gold colored diaphragm on the top left), and this is just via a small hole behind the ACV. If coolant could find its way in through here, it would have to be getting sucked into the engine & boiling off as well. You should see/smell a coolant vapor cloud from the exhaust. Basically, you need an amazing sequence coincidences. I'd start taking things apart until I found the leak, etc...

Aaron Cake

iTrader: (1)

Very impressive!

Is it possible that some coolant hose has been rerouted somewhere? For example, the BAC hose being plugged into a vacuum line or something equally bizarre?

I can't imagine any coolant patch to the ACV. Judging by that engine bay, someone has been playing. Maybe the overflow line from the pressure cap is plugged into the ACV or something?

Maybe someone spilled a lot of coolant into the air pump?

Is the engine actually losing coolant?

Nelson Rebelo

UPDATE:
We found that the previous owner connected the heater hose to the split air nozle and plugged the radiator connector for the heater hose. No more coolant from acv. Now small leak from under carriage passenger side, im thinking heater core maybe.
After that rough idle. Thank you for all your feedback and to RotaryRebuilder on you tube for video response.
Nelson

RotaryRocket88

iTrader: (7)

Just when you thought you'd heard it all...

Aaron Cake

iTrader: (1)

Wow.

snivley whiplash

iTrader: (4)

nice investigation and find. some peps just do not know what they are doing under the hood. hope it works out well for you.