Jeff McConnell

Hi everyone,
I have a 1993 RX-7 TT I bought new. It is mostly stock with the exception of aftermarket AST and radiator. It has 125K miles and am on the 2nd engine.

I have a water leak on the right side of the engine. I have checked the turbo coolant lines and the line from the throttle body, but all are dry. After removing the front catalyst, I can see the water droping off of the rear turbo. But I still can see the source to fix it.

Anybody have any suggestions? I would appreciate another set of eyes to find the problem. Anybody familiar with this model and live near Escondido/Rancho Bernardo, CA?

Thanks,

Rx7_Nut13B

iTrader: (1)

Well it could be one of the crush washers on the turbos (Kinda weird haven't seen this much), or it could be the water line from the rear iron on the top right that goes to the TB.

Jeff McConnell

Thanks for the suggestions. I have taken the top off he intake tract. The hose from the throttle body is down in a well. It does not appear to be leaking, but I can't see it very clearly. Would the water pool in that area or run around the end? It doesn't look like there is an opening down there.

I am hoping that it is not the turbos. They are the original equipment, so it is a real possibility. The last part of the shielding is still in place. How does this come out so I can look straight down on the turbos?

Thanks for your assistance,

gracer7-rx7

iTrader: (16)

Go to Autozone and rent a Coolant System Pressure Tester with the import adaptor. Use it to pressurize the coolant system so you can see where it is leaking from. Works like a charm.

At that age, you should consider replacing all the coolant hoses and get new OEM hose clamps. If one hose is leaking, the others are sure to follow after 15 years and 125k miles.

Get the parts from Ray Crowe at Malloy Mazda. His number is in the FAQ thread stickied in the 3rd gen forum. I think he sells a complete hose kit for ~$165 or so. Add in the hose clamps from him also.

Jeff McConnell

I did get the coolant system pressure tester from Autozone. That is why i know it is leaking and it's approximate location. Without it, the coolant evaporated before it hit the ground.

All the hoses were replaced when the rebuilt motor was installed, about 20K miles ago.

I have disassembled most of the right side of the engine - The pre-catalyst, y tube, and turbo inlet have all been removed. The turbo coolant lines at the front show some corrosion but are not leaking. The turbos are still covered by half of the shielding. Does this half come out without unmounting the turbos?

I have also removed the part of the intake that connects to the throttle body. I can see the water hose way down in the hole. Pushing rags down there come up dry. Is this area sealed from below by the intake manifold? or are there passages through that area?

I would really like to get this car running again, but if I can't find the leak, I can't fix it.

trochoid

iTrader: (6)

Not that familiar with the 3rd gens, but on the 2nd gen TIIs there's a coolant line coming off of the rear rotor housing that feeds the turbo. It may be leaking where the line comes off of the intake mani or the o-ring between the intake mani and rotor housing. 3rd gen guys, if I'm wrong please correct me.

Rx7_Nut13B

iTrader: (1)

Pictures of where the water is located, or where you see it

gracer7-rx7

iTrader: (16)

Yes, Pics would help.

There is the hose that goes from the rear iron to the throttle body. that one is a bitch to get to and can show up as a leak around the rear, passenger side of the engine.

Jeff McConnell

Here are some pictures of what I can see. They are not very clear. It is difficult to get the camera under the car and properly focused.

Also, I pushed paper towel around the hose from the throttle body and pressurized the system. It came back dry - No leak.

Thanks for your assistance and anybody local is welcome to come inspect this for themselves.

gracer7-rx7

iTrader: (16)

So the leak is on the passenger side of the engine bay, correct?

There aren't a lot of coolant hoses over there. There are the 2 turbo hoses. Remove them and inspect them closely. There is the big hose in front of the turbos down low that goes to the heater core. There is the hose that goes from the rear iron (near the rear, second turbo) to the throttle body and there is another hose kind of under the UIM but its up front near the rear of the thermostat housing.

Eyeballing them generally isn't sufficient to determining if a particular hose is bad. Unless its obvious... You may need to pull them off and have a close look for a small split or a hose clamp that has chewed up the rubber. Those are a pita b/c you can't see them until the hose clamp is off.

Build up your post count and post in the Regional section. There are RX7 owners near you and the San Diego guys have a monthly meet the first Sat of every month down in Mira Mesa. When I lived there, it took place at Fuddruckers.

Jeff McConnell

Yes, the water leak is on the passenger side of the engine compartment. I can not see where the leak originates, but it drips off the rear turbo area with the front of the car jacked up. I can only see it when I pressurize the system via pressure tester.

I can easily see the turbo coolant hoses and the water heater hoses. They are dry and both ends are also dry. I don't see how they can be the problem.

I took off the top to get to the hose from the throttle body. It also appears fine. I can reach it, but using paper towels and the pressure tester, they come back dry.

The only possible place is interally on the turbos. I am going to try and by pass the turbos (plug or loop the lines together) and check if I still get the leak before I remove them. Does this sound feasible? Any other suggestions to determine where it is leaking?

I used to be able to discuss things like this with Dave and Matt at Speed Machine Performance, before they closed. Anybody know if they are still in the area and how to get in touch with them?