Rotary4tw

iTrader: (3)

Hello again... yesterday morning my system seemed to have some sort of spike, and blew an intercooler/intake line off on the left side of the car. At the same time, coolant started to leak from the bottom of the car. This was yesterday...

https://www.rx7club.com/showthread.p...t=Coolant+Leak

So we check the system for leeks. Not the AST, not the radiator, not the turbo coolant lines, not the thermostat. It looks like the cause of the leak is coming from the back side of the engine compartment, next to the rats next, passenger side, along the firewall.



This leak takes place when the system is not pressurized, which leads me to believe it's a hose. And the one below. The problem is we can't get back to the SOaB. Are there any gaskets that could be leaking in that area that may also be the cause?

I can reach under there from the bottom of the car and follow that hose, and there is about an inch of coolant sitting in a little puddle on top of the engine, right near the base of the hose. I can't feel if it is completely attached or just split or what. Regardless, we are going to have to get down there to inspect it.

We ended up taking off the top of the manifold to try to gain better access, and now I'm worried we may not get it all back together properly. Along the way, we found a few things in the vacuum system that were troubling...



I remember the previous owner saying that the whole system was replaced with new hoses by the dealer... would a dealer use glue to connect one to a broken off nipple? I'm not sure, maybe they did. Looks like it didn't hold very well...

Back to the coolant leak...

From underneath, it's running down like this...



You can see some of where the leak is from these pictures...



This one shows it best... if you look hard enough you can see the puddle of coolant down there.



So I a few questions:

1) What is the best way to get down and replace that hose... is it the way we are going, with eventual removal of the next engine component that sits about the hose?



2) Where can I order a replacement hose for this today, so when we finally get down there in three days, I will have it ready to go.

3) Is there anything else that could be causing a leak down there instead of a disconnected or leaking hose?

4) Should I be running a 13psi radiator cap instead of the 16psi cap I put on when I got the car? Is there just too much pressure in the system?

Thank you in advance.

-Rotary for the "please make my car run".

SUPEROTARYPOWER

13PSI would work better, I have replaced that hose myself with a PLUG CAP! Only premium plugs securely fitted onto that metal pipe out your rear rotor housing will work and last without worries. Then go ahead and cover the intake manifold cover the hose goes to but the flow comes from the motor so no need to make sure the on on the intake can handle high pressures

alberto_mg

before you order the hose make sure the existing clamp is on tight and is down far enough to be clamping onto metal. order the hose from ray at malloy mazda. also order 2 new factory clamps. the stock clamps are better than the worm hose clamps (search on that if you want). see faqs for his number. you can also order a new pair of solenoids from him to replace the broken ones.

that hose delivers coolant to the throttle body so that when the car reaches operating temps the thermo-was jammie separates from the throttle body for cold idle operation.

also locate a set of very long pliers where the ends are bent. you should be able to find that at sears. you will need that to access the hose clamp. damonb had posted a pic or part number once, but i can't seem to find it.

as for the radiator cap, it probably doesn't matter all that much. order a new one from malloy while you are at it.

good luck!

wstrohm

Looks like you might be able to get at it if you remove the Air Control Valve... but not sure.

I think these might be the pliers referred to above... Craftsman P/N 45596. I could not have done the vacuum hose job without them.

Rotary4tw

iTrader: (3)

You plugged that hose coming out of the engine? How is that possible, is it some sort of optional line that does not block the system?

?

-R4tw

Mahjik

iTrader: (1)

You can bypass the TB and plug both sides of the line. However, some people (including me) don't think it's a good idea as it can create hot spots. It's best, IMO, to either run it back to the TB or bypass the TB as long as you keep the line somehow.

dgeesaman

iTrader: (7)

It's going to be hard to get to that line, but really those vacuum hoses and fuel lines are the only thing in your way, if you can get around them. That's bad luck to pop that one - it's the hardest coolant hose to reach, unless the transmission happens to be out or you're doing the vacuum hose job.

That glued solenoid is not a good thing. You'll need a new or good used one. The good thing is you can replace it later without removing the UIM again. But you wont' get normal boost until you replace it. You can try repairing it, but by the looks of it they were already messed with. PM V8KILLR about them.

The hopefully easy way: using pliers like these: http://www.harborfreight.com/cpi/cta...emnumber=38598 and maybe a peek mirror, remove the clamp and hose. It should be kind of straightforward to reach down on the firewall side and remove it, or if the clamp is oriented in the wrong direction you might reach down into the fuel lines to get to it. Don't bend/break any vacuum lines leading to/from that solenoid rack - you're right in the part of the car that takes the engine bay heat hardest. In any case, it's going to be difficult to work there because you'll be leaning way over the car. Pull the hose and replace.

The other way is to remove all that stuff. It looks like this would all be best done.
I strongly recommend getting a new Fuel Pulsation Dampener since that's right beside the hose connection, and an old one is a fire hazard. As well, you're now in as deep as the full-blown vacuum hose job, so you can decide to change all the remaining vacuum hoses, get the injectors cleaned, install new injector o-rings and grommets. The bill for these parts will be a few hundred bucks minimum, and expect a week or two of downtime unless you have experienced help.
The hose job looks like this: link

Let me say this: doing the hose job is not easy, and it will be challenging as a new owner unless you have help, or a lot of patience and skill with reading diagrams.

Rotary4tw

iTrader: (3)

I appreciate the help...

We will try to get to get down there with a tool and see if we can access the line. Last night was my fathers first experiences with the "Rat's nest" and I heard him express his... "opinion" on it's design many times. lol They make for good memories and hopefully we can get her back together.

As far as replacement goes:

The solinoid, thats the part with the four nipples that comes out, and the vacuum lines attach to it? Yah, one of the nipples is broken so I will just order a new part.

Should I look in the parts section, or can this be purchased through Malloy?

I'm going to inspect the other hoses too, but most of the others actually look very new, and are on tightly with no signs of brittleness. I'll keep investigating and keep you all posted!

Thanks again team Rx-7!

-Rotary 4tw

dgeesaman

iTrader: (7)

PM that guy - he has the solenoid you need and a few more. One of them is the wastegate/precontrol pair that you're looking for. Malloy has the green solenoid pair for $120, so maybe it's better to get a low mileage (under 50k) used one first. Use the money you saved to buy a Mityvac Silverline Plus vac/pressure pump kit.

The hoses can be deceiving - only the ones on top are changed - the ones going under the fuel rail look original. I suggest if you want to do a reliability project, to plan going in again, removing the rats nest, cleaning the injectors (you can get new o-rings too with some injector cleaning shops like RC Engineering), changing the FPD, replacing the remaining hard rubber lines, and testing all of the solenoids.

The rats nest is a hatred/awe thing to me - it performs a rather complex task (emissions switching and turbo control) that is awe-inspiring when functioning, but nasty when it misbehaves.

Dave

quicksilver_rx7

I personally would recommend three things here.

1.) Take your time while doing this and PAY ATTENTION to what you do.


2.) Follow the advice that Majik gave.....either run that hose back to the throttle body or to the back of the Water Pump. Either way, replace it with a silicone hose.

3.) Replace that solenoid with a new one unless you can find a VERY MILDLY USED one. You can definitely tell a new or slightly used one from an abused one.

dgeesaman

iTrader: (7)

But there is no guarantee.

I got one with 15k miles on it, looked brand new - it leaked. My original with 63k passed the test no problem. IMO, it's cheapest/best to buy a group of used solenoids with low miles, test them all, and expect to fail a couple. Since the rack solenoids are all basically the same, so you'll have a group of spares.

Dave

quicksilver_rx7

Agreed. I was refering to the WG solenoid, not the rats nest solenoids. The WG is almost $200 brand new. Could probably find a good condition one a little cheaper, IF you could find a good condition one.

Kento

Might want to add that if one solenoid is that old and crusty, chances are good that the others aren't too far behind. Inspect and test all of them (if you're doing the vacuum hose replacement, it'll be a good time to do it anyway), and replace as needed.

gcthree

You can repair that solenoid. Go to www.rotormafia.com, and there's a how-to on the repair of that exact solenoid.

I bypassed that coolant line by putting a rubber plug in the nipple, with some silicone sealant, and then put a silicone cap over it with a clamp.