I've had a slow coolant leak for a while. Finally tried to find it today. There's a pool of coolant just above the LIM under the primary fuel rail. Can't figure out where it"s coming from.

My BAC is removed and I have a straight line running from the T-stat housing the to back of the motor where it used to go and it doesn't seem to be leaking, It's a fairly new hose and it"s not damp around it. Also doesn't seem to be coming from the T-stat itself. Any ideas?

 

coolant line to the throttle body - if its still there?

 

It's not, that's the one that I was talking about that I ran a straight line from the T-stat housing the the back of the motor. It doesn't seem to be leaking.

 

I think he meant the short L-shaped hose under the throttle body. You only can see it if you remove the upper intake manifold. If it's not that hose the only other possible leak would be the O-rings between the lower intake manifold and the engine but that's not very common.

 

if it's a turbo engine i would guess your intake manifold o-rings are shot. if it's an n/a then you can rule that out(unless it was rebuilt with turbo rotor housings).

 

Wow, I should have specified, haven't posted in a while. It's S5 TII. I was thinking there was o rings in there but couldn't remember. That's probably it. I'll have to order some new one. Thanks.

 

Could also be the temp senders on the back of the water pump housing. If those are loose coolant will collect there.

 

^ True dat!

 

if i were you i would eliminate the hose from the tstat housing to the rear rotor housing all together and fill the opennings with jb stick weld.

 

Please explain.

 

i did this when i removed the emissions on my 87. check out the tech section on rotoryresurection.com. after performing all the mods the car didnt run better or anything, but it didnt run any worse either haha

 

I'd recommend plugging it with a 1/4" NPT plug...:
https://www.rx7club.com/general-rota...t-iron-941657/


I think it's probably your lower intake manifold o-rings.... mine used to do that:


I plugged the passages with freeze plugs:


then ran a line from my rear iron (1/4" NPT -> -6AN) to my turbo... (-6AN -> M16x1.5)







...Or you could just replace the o-rings....

 

yup i ended up installing a threaded insert inplace of the rusted out fitting then ended up filling it in anyway after emissions delete. oh well./

 

There wasn't even an o ring on the side that is blocked off going into the LIM...

I thought I remembered reading somewhere that you want to keep the hose from the T-stat to the rear iron because if you plug both ends the coolant doesn't flow right? Could be wrong.

Eage8, so you blocked off both the small coolant lines coming off the t-stat housing? The one going to the TB and the one going to the turbo, then ran the line from the line from the nipple on the rear iron to the turbo. Coolant flows correctly this way? Also, if I were to do this I imagine I could just use rubber radiator hose, I'm moving in a couple weeks and don't have the time and money to do the steel braided right now.

Thanks for all the help guys.

 

i sure hope you read wrong! i got this info straight from the tech section on rotorressurection. man that would suck *******!

 

I'm sure your fine then, I probably did. I see you live in San Antonio. I'm moving to Austin at the end of the month. How's the rotary scene out that way?

 

it's not a main coolant passage... (obviously due to it's size) so it can't possibly affect flow that much. it's there solely to warm up the throttlebody, thermowax and BAC valve.

and yes, I blocked off the coolant passage on the waterpump housing with another 1/4" NPT plug.
https://lh5.googleusercontent.com/-1...UNSET%255D.jpg

If you look at the flow chart in the FSM, the coolant flow is going the correct way through the turbo. So that's fine...
http://www.rotaryheads.com/PDF/2nd_g...ing_system.pdf

if anything the coolant is in the engine slightly less time so the turbo is getting cooler coolant...

 

I still have the turbo return line on the waterpump housing if that's what you're referring to as the second small coolant line on the thermostat housing.

 

[QUOTE=eage8;11372323]
I plugged the passages with freeze plugs:

/QUOTE]

- what do I ask the autoparts man as far as part#, application, size, etc. of this plugs?
- did they need modifying e.g. filed down to be flush w/the housing?
- what sealant if any did you add to the plug?

since i have this same leak currently i was also thinking about re-routing the coolant flow but redirecting the flow from the BAC to keep the thermowax functional.

 

I got them from napa. They're 20mm brass freeze plugs. (steel works too though)
NAPA AUTO PARTS

no modification, I just put some RTV on the edges so it would seal a bit better.

 

thanks for verifing the coolant line delete aint an issue for me.