Could be the water jacket O rings in the intake manifold. These seal the intake manifold to the block and allow coolant to pass into the manifold to speed warm up and cut emissions.

Can you see any water collected on top of the engine down below the carb on the right (driver's) side? This usually happens when the O rings leak.

You will need a flashlight and have to look down below all the rats nest tubes to see it, but if there's green fluid down there its coolant, which could be washing down dirt and oil from outside the engine to give your "oil" leak.

If you can collect some of the fluid dripping from the bottom of the car, mix it with some water (or oil) and see what happens!

From your pictures, the fluid looks to be less viscous than oil, see how it runs over the concrete and spreads on the plastic? Might just be dirty coolant.

 

It could also be that a dripping coolant leak from the intake o-rings (as Ray discussed) has over time softened & damaged the pan gasket, allowing oil to leach out.

Or it may just be to separate issues; slight o-ring leak, moderate pan leak, stuff mixes as it drips off the engine. That gives you oily water, or watery oil.

 

Sure does seem to have a green tinge to it.

 

What's the best way to remove the intake so I can get to the gaskets / o-rings? I got that to remove the oil pan gasket I'll need to lift the engine a bit (fun! scary! new ground for me!).

And what do I need? One intake gasket and Two o-rings? The car has everything on it from original. All of the rat's nest... Is there a way to remove it in whole, or do I have to really take the rat's nest apart?

And, if I end up removing the exhaust manifold, I need to replace a gasket or series of gaskets there?

Yep, noob here...

thanks.

 

Here's the leak all poured into a cup. The water I mentioned - that I noticed along the oil pan bolts closest to the transmission on the passenger side. Divin may be on to something ... multiple leaks mixing together.

 

if it's leaking more while on the ramps it is probably the oil pan, since the oil level is probably now above the pan mating surface.

 

sadly, it would likely be a bit more grim than that.

i was tracing coolant loss a few years. no leaks. no extra pressure. no smoke. at any rate, i had to change my pilot bearing and decided to install my exhaust system at the same time. i pulled the exhaust after dropping the tranny. while removing the clutch, obviously i had to turn the engine and all of a sudden it was like Victoria Falls - coolant literally splashing against the floor as it got pushed out the exhaust ports! it turned out to be coolant seals.

go ahead and check the intake like everyone else said, it would be nice if that's all it is. at least you've confirmed it is antifreeze so you're closer to finding the issue.

 

It would be best to diagnose this thing before undertaking major repairs, like removing the intake manifold to replace coolant O rings that might not be leaking.

First question: Is this stuff in that cup water or oil?



Fortunately, this is a really easy question to answer.

Currently, you have one phase - all the fluid is evenly mixed.

To test to see if the stuff in the cup is water or oil, add 1/2 cup of water and stir well. Then observe:

If the water mixes with the mystery fluid, you'll still get one phase: The mystery fluid is coolant.

If the water doesn't mix with the mystery fluid, you'll get two phases, with the water on the bottom. The mystery fluid is oil.

In any event, wherever that stuff is coming from, whether it's coolant from the radiator or oil the engine, you should be seeing a significant loss in fluid level that would also give it away - check your fluid levels!.

At this point, I'm guessing a coolant leak, which would explain, much as DD suggested, the water that's beading up around your oil coated oil pan (even a small oil pan gasket leak will coat the pan with oil, as they almost all are). But why guess? Do the mixing test and know for sure.

Concerning the long term, if it turns out that it's an intake manifold coolant O ring gone bad, now is the time to do some major work because Just to do the manifold O rings you'll need to remove (and replace) the rats nest and carb, which is quite a bit of work. One the other hand, the intake gasket and O rings are inexpensive, you can order these from mazdatrix or the dealer, so at least the wife won't be complaining.

If the coolant O rings are leaking, this would be a good time to do some serious work under the hood, get everything in top shape and cleaned up, inspect the rats nest solenoids and connections, all air and water hoses, etc, which will be a lot easier while you have everything apart.

Maybe even think about upgrading that stock exhaust, which would involve removing the exhaust manifold if you want to go with an aftermarket header (Racing Beat is best, but expensive). If you do remove the stock exhaust manifold for any reason, you'll need a new gasket, whether you put the stock manifold back on (not advised) or install an aftermarket header (now's the time if your car is emission exempt).

If you want to upgrade the exhaust without the expense of a new header and presilencer or the trouble of removing the stock exhaust manifold, there's a cat replacement pipe available from RX7.com that bolts in place of the three cats. Best part of this option is that you can do it for for free, pm me for details.

 

Well, taking Ray's suggestion, I now know that oil, it ain't! Around 5:00 this evening, I mixed in about 1/2 cup of water. Went about my business and returned at 9:00. Everything is nicely mixed...no oil on top.

So, now what? Go for taking off the intake manifold? Any pointers? I gather I'll need to take the carb & rat's nest off. Per my question above, can this be done as a unit? (The rat's nest, that is).

What needs to be on my shopping list? Two o-rings and one intake manifold gasket? Anything else?

Oh, and Ray Green....you have mail!



Note that the bubbles are just that, bubbles. There is nothing floating on the water.

Bigger picture here, if you really care. http://southernfriedherring.com/?p=148

 

Taking the intake/carb/vacuum rat's nest off as a unit is the way to go. There are four nuts and two bolts that hold the intake manifold to the engine. There are, I believe from memory, two bolts that hold the vacuum rats nest. You have to pull one of the solenoids off to get to at least one of the bolts. The hardest part doing it this way is putting the accelerator cable back on.

Take lots of pictures at different angels.

 

I've looked for a write up, because I'm sure there is one, but most of what I'm finding is "I removed my rat's nest because....". As in, I did it for simplicity, performance, etc. Is there a write up that shows the actual removal? I'd like to get it all back on there once I'm done.
And thanks again! I wish something like this site had existed twenty years ago (or more *cough*cough*) when I had my first RX-7.

 

If.you are sure its between the transmission and engine then it.is the.freeze plug behind the.flywheel on the rear iron/plate.

 

OK, it's looking like the coolant O rings to the intake manifold. But let's be sure before you tear into probably more engine work than you've done in awhile.

With the engine slightly warm, get out your degreaser (I recommend the cheap walmart or autozone stuff, not sure that Soilant Green stuff isn't ecohype) and soak everything down around and under the carb, especially on the passenger's side of the engine. Let it soak 15-20 minutes, then hose everything down real well with the garden hose, not too much pressure, just enough to wash off the degreaser and get down to clean metal.

Now let everything dry. If you have a compressor, use it to blow out all that water sitting on top of the engine under the carb and rat's nest - that's where you need to be looking for coolant leaks later on. If you don't have a compressor, you'll need to do your best to towel off all the wet spots down in the crevices, which is a PIA. (If you don't have a compressor, and your birthday is coming up, a compressor would be the perfect thing for your wife to surprise you with - it will be good for all kinds of things).

With everything dry and the engine cold, check your coolant level at the radiator cap. If it's a little low, don't add anything yet, just note the level. If the coolant is down below the radiator fins, top it off with the garden hose or some deionized water, if you have it. After you're done with all the procedures below, check the level again to see how far it's dropping, which should account for the coolant that accumulates on the garage floor.

Now start the engine and let it run until it comes to temperature (5-10 minutes, garage door open) or until you see a good batch of coolant accumulating on the garage floor. Observe all the while for coolant leaks around the intake manifold or anywhere else. This will require a good flashlight and a mirror to get a good look around the entire intake manifold where it bolts to the engine.

When you see a leak around the intake manifold, it's time to order those gaskets. If you see it leaking from someplace else, you still have some diagnostics to do and the possibilities get a lot uglier (note the comments by Junito1 and Diabolical1 above, which would indicate an internal engine leak and require a complete rebuild, which is probably not a bad idea anyway if you plan to keep the car).

But chances are it's the intake gaskets, a common problem on unmolested specimens like the one you picked up.

So you'll probably be removing the carb, rat's nest and intake manifold, which is actually kind of fun, once you get into it. It's not rocket science, all you need is the right tools, a lot of patience and good skills disconnecting things without breaking them (and remembering where they go when you have to put them back. Hint: take lots of pictures during the tear down).

There's a procedure in the FSM or Haine's, you should follow that, but basically KC REPU nailed it, you want to remove everything in as big a piece as possible, starting with the carb and rat's nest. But don't hesitate to remove a specific solenoid or dashpot to make it easier to gain access to any hard-to-get-to nuts and bolts, this can save a ton of time and frustration.

Enjoy, this is the best part of being the proud owner of a minty unmolested 1st gen RX-7.

 

The FSM contains a step-by-step as part of engine disassembly, but not one for just removing the intake manifold.

Here's a sketch of how it goes, should you need to do this. Ray's tests are crucial to do first, as you don't want to just blindly start this kind of work without a real purpose to it.

1) Drain radiator & engine block of coolant. Rad gets drained either from the drain plug (if you have one) or by disconnecting the lower rad hose. Block gets drained via a hex-headed plug and aluminum crush washer on the bottom edge of the left side of the middle iron, below the oil filler.

2) take off the air cleaner; note routing of hoses, & either tag or take pix (general rule is take tons of pix!)

3) remove carb. This involves disconnecting (and plugging) the fuel lines, electrical connectors, a few vacuum lines, the OMP linkage & lines, four nuts holding the carb to the mainfold, and the throttle and choke cables. I personally find it easiest get everything except the throttle/choke cables undone, then unbolt the carb, lift it and set it on top a board placed over the carb studs, then rotate it and disconnect the choke and throttle.

4) the rat's nest and the carb spacer can be removed as an assembly if you carefully locate all electical connections and the few vac lines connecting to the dizzy and the firewall. One solenoid has to be unbolted to get to one of the bolts that holds the ratsnest to the block. Be careful with the carb spacer (it's plastic) and do NOT remove the permanent 'gaskets' from it.

5) disconnect and remove the ACV from the manifold to make easier access. Note how the spring-loaded valve plate goes into the manifold, if you have one.

6) at this point you can remove the intake; if your exhaust still has the factory heat shield, remove it first for better access. Some of the nuts are kinda tricky to get to, but all are reachable without pulling the exhaust manifold.

You can see a lot of these steps (granted, for an SA, but still very similar) in this photo album, which docs my last complete engine pull and rebuild. They're mixed in with other disassembly/removal steps, but it should give you a good feel for where you're headed. I didn't unbolt the manifold until I had pulled the engine because I'm lazy; with the Thermal Reactor on the SA's being much larger than the exhaust manifold on the FB's, getting to the manifold bolts is easier with the engine out - - but I have pulled the intake several times over the years with the block in the car. It's definitely doable.

Dec 2011 Engine Removal Photos by GrunthosToo | Photobucket

I don't recommend trying to pull the carb and manifold as a unit. It seems like it would simplify things, but in fact it makes the work much harder; it's a heavy and fragile assembly to try to handle as one piece, and you'll likely need to separate them before reassembly anyway so you bolt up the manifold properly.

 

While most of the car looks clean, it is pretty grimy (and I think wet) on top of the engine under the carb. I'll haul it out of the garage tomorrow or this weekend and proceed with Sir Green's suggestions and we'll see where things go. I do hope it's only the gasket and not something uglier. I knew the car would always need some work when I bought it, and fully expect that with a 27+ year old car. I'd just rather not have major issues *now*. (I bet everybody says that!)

I do have the FSM. Sounds like I need to look for a Haynes manual, too.
thanks again!!

 

Well.... followed Ray's advice and (re)cleaned the top of the engine. Ran the air compressor and got things decently dry. Fired up the car and let it idle for seven or eight minutes. The leak hasn't manifested itself yet. Then I took a spin around the neighborhood. Still no leak. But, I know it's there because 1) I had to add coolant (obvious, I guess) and 2) the area under the carb and over the intake was hugely grimy, wet, and just plain nasty. So, I'm fairly certain that's my issue. But, I'll watch a little bit longer....

 

If this is an 84/85 GSL, that was the year they offered the revolutionary new Autofixit option, which autorepairs most leaks and other common problems.

Its my favorite aspect of the 84/85 GSLs, all you need to do is add a little TLC.

You might be thanking the Mazda Engineers and Rotary Gods for this one.

Still, that was a lot of antifreeze to go unexplained.

 

That is still about the most disgusting glassful of stuff I've seen in a long time. Looks like what they'd wring out of a bar towel the morning after St Patrick's day.

If it's leaking on top the manifold between the intake and the block, that's a fairly large hollow up there. may take a while for it to fill up before it overflows enough to leak downwards.

 

@Ray, you crack me up. Sadly, it's an 'S' model, so we know there's nothing auto about it.

@Divin, thanks for the tip. I hadn't realized what a void it is under all that stuff until I was dinking around with it today. And yeah, that is a pretty gnarly glassful.