Coolant leak above LIM
#1
![FL](https://www.rx7club.com/images/icons/fl.jpg)
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?
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?
![Name: coolant_zps5849f488.jpg
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#2
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?
![](http://i1096.photobucket.com/albums/g332/timebomb7/coolant_zps5849f488.jpg)
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?
![](http://i1096.photobucket.com/albums/g332/timebomb7/coolant_zps5849f488.jpg)
#4
Full Member
![](https://www.rx7club.com/images/misc/05_year_icon.png)
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.
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#10
#12
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:
![](https://lh4.googleusercontent.com/-loidSBusdc8/UI3uGUuBiqI/AAAAAAAACaI/Id4hUJSQ5gM/s800/%255BUNSET%255D.jpg)
I plugged the passages with freeze plugs:
![](https://lh5.googleusercontent.com/-bI_kZZzhA6c/UJCcB50tW7I/AAAAAAAACac/HOuJkKpsaX4/s720/%255BUNSET%255D.jpg)
then ran a line from my rear iron (1/4" NPT -> -6AN) to my turbo... (-6AN -> M16x1.5)
![](https://lh5.googleusercontent.com/-CL3_OHLPIQo/UJHadSkiH_I/AAAAAAAACa8/ywXH-4717hE/s512/IMAG2585.jpg)
...Or you could just replace the o-rings....
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:
![](https://lh4.googleusercontent.com/-loidSBusdc8/UI3uGUuBiqI/AAAAAAAACaI/Id4hUJSQ5gM/s800/%255BUNSET%255D.jpg)
I plugged the passages with freeze plugs:
![](https://lh5.googleusercontent.com/-bI_kZZzhA6c/UJCcB50tW7I/AAAAAAAACac/HOuJkKpsaX4/s720/%255BUNSET%255D.jpg)
then ran a line from my rear iron (1/4" NPT -> -6AN) to my turbo... (-6AN -> M16x1.5)
![](https://lh5.googleusercontent.com/-CL3_OHLPIQo/UJHadSkiH_I/AAAAAAAACa8/ywXH-4717hE/s512/IMAG2585.jpg)
...Or you could just replace the o-rings....
#14
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 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.
#17
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 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.
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...
#19
Senior Member
![](https://www.rx7club.com/images/misc/05_year_icon.png)
[QUOTE=eage8;11372323]
I plugged the passages with freeze plugs:
![](https://lh5.googleusercontent.com/-bI_kZZzhA6c/UJCcB50tW7I/AAAAAAAACac/HOuJkKpsaX4/s720/%255BUNSET%255D.jpg)
/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 plugged the passages with freeze plugs:
![](https://lh5.googleusercontent.com/-bI_kZZzhA6c/UJCcB50tW7I/AAAAAAAACac/HOuJkKpsaX4/s720/%255BUNSET%255D.jpg)
/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.
#20
- 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.
- 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.
NAPA AUTO PARTS
no modification, I just put some RTV on the edges so it would seal a bit better.