RX007CYM

iTrader: (2)

Decided to come up with a game....

Searched and looked at some of the cooling diagrams but cant figure it out. Took the car out to get ready for a track day and the temps got to hot. Was a few blocks from my house, thank goodness, and pulled up into driveway car off/fans on, and coolant was hissing and spewing out of somewhere under the UIM. So I take off the UIM and primaries and now my head hurts. Please help with the attached picture items 1-6. If I label anything wrong please correct me. I am good with 7s but not an expert. Thanks!

gracer7-rx7

iTrader: (16)

Oh boy.

There are 2 coolant lines in the vicinity of the top of the engine under the UIM.
- The throttle body coolant hose that goes along the back of the motor from the pax side to the driver side. I have a thread with pics of it from when mine burst if you wish to search for it.
- At the front of the motor behind the water pump and alternator.

If you haven't replaced either yet, might as well replace both since the car is apart. Get yourself some new OEM hose clamps for them also since they are constant torque and won't loosen up after a few heat cycles like worm clamps. BTDT.

When you have everything back together, go to the local auto parts store and rent a "coolant system pressure tester" (sometimes called a radiator pressure tester) w/ the adapter for imports and run a coolant system pressure test to check for other leaks.


What is concerning is that it looks like your OMP hoses aren't connected to the OMP squirters. Is that right? If so, I hope you are pre-mixing... You should address that also while you are there.

RotaryEvolution

iTrader: (30)

could be that the engine was built with early model turbo housings with the coolant passages in the LIM, that is a common spot for those housings to leak coolant onto the top of the engine.

get the pressure tester and that should point you to the leak.

are the oil jet holes in the housings plugged off or are they open? if open then you need to hook the OMP back up or block off those ports and premix the fuel. leaving them open will create a vacuum leak/rich condition/boost leak and cause an oily mess as well as sucking dirt into the engine.

ugh, looking at this mess makes me despise working on these cars and the morons who put them together.. i see this sort of **** almost every day.

got_hp

when i first purchased my car, i had a coolant leak (ended up finding out it was TWO leaks) in the same area.

it was because of the way the previous owner did the throttlebody bypass. normally it goes from the back of the engine block (#2 in your pic i think) into the TB, then into the neck of the back of the water pump/neck area. instead of just putting in a new hose from point a to point b (bypassing the TB), the owner instead capped off point a and b with rubber nipples and come metal spring clamps.
the problem with this is that when you combine the high pressure that the coolant is under, and the rubber getting very hot and pliable due to engine heat, the rubber nipple would eventually fail.

the first time i found the leak, it was behind the waterpump neck area. i didnt know any better, so i just replaced the rubber nipple with a beefier rubber cap and worm clamp. a few months later, that also split and leaked, due to the reasons above.
after fixing that, the next leak spring from the one at the back of the block, which creates a nice little puddle under your UIM.

after a third leak, i figured it out and did it correctly, using fuel hose, which is thick enough to withstand the heat, and also can be clamped down quite tightly without fear of cutting through the rubber. 2.5yrs later and about 45k miles and no leaks

XLR8

iTrader: (52)

#1 is fine as long as they are connected, but I would add zip ties or replace with OEM. Even better yet, ditch the OMP and premix. Banzai Racing sells a fitting kit to eliminate the injectors.

#2 is a coolant port. It is intended for the throttle body. Coolant flows from this port to the rear of the TB, then from the front of the TB to the water pump housing. I never liked the idea of caps as they wear quick with pressure. I used a hose to route the rear iron port to the water pump housing port. This is also a great place to utilize a water temp gauge sensor.

#3 is not coolant. Is the air atomization port. It often gets blocked off. It is used to supply a direct positive pressure port from the turbo to help with fuel atomization.

#5 could be an indicator of the water pump housing port leaking, or one of the 2 sensors that screw down to the rear of it. I had a leak here after my single swap. They are easy to overlook. It's right on the back side of the big bracket that the airpump mounts to. There are 2 sensors back there that screw into the housing. Check them.

RX007CYM

iTrader: (2)

I will get a tester and see where it starts coming from. I disconnected the jets and will reconnect so no need to worry there. I thought by opening everything up I was going to find an obvious split hose but there was no hoses except for the one running between the omp jets. Curious to see where it comes from once the tester is hooked up.

I have a mechanical OMP from a 12A hooked up and from all who have seen the set up (builders and tuners) love it. I will add zips to the hose running on top of the two jets. Thank you for looking at the numbers on the pic and responding to them. Very much appreciated.

A little back history on my baby. Bought the car in '01 stock. I am the second owner. I did some AutoX but wanted more. In '07 I had the car built and converted to single. In 2010 I dissembled the engine and transmission with a friend. Had the shortblock rebuilt, and resurfaced the aftermarket clutch. After the rebuild had Kilo tune her to perfection. During all this time I have enjoyed taking her to HPDEs and have been without any major mechanical issues until this coolant problem (I guess this really isnt major, just takes her off the road until she is fixed.). After I find the leak I will button her back up and go back to the track.

RX007CYM

iTrader: (2)

Rented a coolant system pressure tester. It was #2 the capped off nipple. It lasted 4 years this way so I just replaced with the same and will fix next time it goes. Thanks everyone for the input.

RotaryEvolution

iTrader: (30)

better off running a hose from there to the water pump housing as a bypass. i've seen one person lose a motor to those caps.

Mahjik

iTrader: (1)

If you do plan to use another cap, coat the inside of the cap with something like RTV or some other sealant to protect the it from the extremely hot coolant.

RX007CYM

iTrader: (2)

Thank you both for the advice. I unfortunately already buttoned her back up. When it goes again I may just route to the pump.

I measure water temps both from my microtech and a Prosport gauge in my gauge pod. The sensors are on opposite sides of the block. How did the one engine fail? Were they not paying attention or just didn't want to pay for a tow? If I was any further from home I would have shut down and waited to cool off and then get home and if I was any further then that I would have towed...

RotaryEvolution

iTrader: (30)

pulling an incline so the temps were already getting rather hot, with the stock ECU temp sensor location once you start losing coolant after a while it gets below the level where the sender can read the temperature.

it's easy to think you watch the gauge like a hawk but even a 2 minute interval can be the difference between normal and overly hot.

DaveW

Every cap I have ever seen has no reinforcement to withstand internal pressure. Therefore, I would not trust any of them in a situation where leakage can create a disaster. Much better is a short piece of reinforced hose on the fitting with a grooved brass plug at the end, and a hose clamp at each end. Or, just bypass, as mentioned above.

IRPerformance

iTrader: (41)

Don't cap the coolant nipples like that. They will fail over time. Either weld them shut or loop the coolant hose from the rear iron to the nipple on the waterpump housing to bypass the throttle body. I don't like welding on the actual iron so I pinch the rear coolant nipple shut and then weld it. The others I remove and tig weld. If its not leaking at one of the points mentioned above, the only thing I can thing of is someone was cheap and may have used 2nd gen rotor housings that have coolant ports in the rotor housings. I have seen cases where people try to rig them shut with jb weld. They all eventually fail.