Hey All,

I just got an 85 RX-7 GSL-SE from a my dad'd boss who was the original owner of the car. It's been inspected and they found a large oil leak in the front driver side of the engine, dripping right on top of the protective plates on the underbelly of the car. Just got an oil change today, it's now at 181,000 miles and it was leaking pretty solidly after running it hard for about 30 min.

Car sounds real smooth and oil pressure norms at around 60 when accelerating, 45 (min) when idle.

Has anyone else had a similar problem on that location of the engine? I've been told it was kept in real good shape, the car was his 'baby' but it has been sitting for the last 7 months until i purchased it.

Im hoping it might just be a dry rotted gasket or something, but there isn't any evidence inside the engine of such.

Please help!

Thanks!

 

Without seeing the leak itself and knowing its an SE I would guess its probably the oil cooler lines. Once oil gets on the oil cooler lines the rubber degrades and **drip**drip**...

-Erik

 

First off, welcome to the 1st Gen boards. You'll find that there are a wealth of helpful people here who have a lot experience with these cars. You'll also find that you've acquired the creme-de-la-creme of the 1st Gen cars in your GSL-SE (or 'SE). Run a search on 'SE' and you'll be able to gather a lot of information that will be useful in the coming months.

Now, on to your oil leak...

The SE has a front-mount oil cooler (FMOC) that uses two high pressure hoses for supply and return. On your oil leak, since it's on the driver's side (also where the Oil Cooler Lines run), it's likely that one of these lines has burst internally and is allowing oil pressure to leak out. This is a critical part failure and needs to be repaired very soon. I would even recommend that you not run the engine until you can determine the extent of the leak and get it fixed. If it's loosing that much oil, you'll need to watch your dipstick and ensure that it's topped off all the time.

Oil starvation will kill a rotary engine faster than anything else, because the rotary requires oil cooling for 1/3 of the cooling of the engine as it runs. The other 2/3 are the radiator coolant and adiabatic cooling through thermal heat to the environment.

The Oil cooler lines look like this;


These are the aftermarket 'braided hose' replacements that are much more durable, teflon inner core for better durability, and dress up the engine bay considerably. They are also cheaper than the stock Mazda factory replacements, and they'll last the life of your car in most circumstances.

Pricing is available here, via www.mazdatrix.com:

http://www.mazdatrix.com/b6.htm for $124.00 (both lines). You will also need the connectors to fit these 'dash-AN' hoses to your stock FMOC and the engine block.

Take care of this car, and it will take care of you. If you have any other questions, such as new SE tips or such, just reply back here or start a new thread,

 

Might want to warn him about the oil cooler fittings cracking if torqued on too hard, Duck.

 

lol

 

Hey, the comment about heat shedding to the environment didn't come out quite right, but you guys knew what I meant!

On the torque issue; the FMOC is made entirely of aluminum, so those fittings on the OC must be tightened very carefully to ensure that they don't get hairline cracks in them from overtightening. As you install the new OC lines, tighten up the fittings to the hose ends that connect to the cooler and then install them until they are just a bit beyond hand-tight. No kidding. It's not much.

Then, install the rear fittings on the engine and torque those down, then install the engine-side hoses to those fittings and tighten them down. Now, when you start the car, you're going to get some oil leakage from the FMOC hoses and fittings - this is because they're just hand-tight at this point. Grab a 23mm (or is it 24mm?) box-end wrench and tighten both fittings JUST UNTIL THE OIL STOPS LEAKING - NO MORE.

This way, you'll not overstress the aluminum 'bung's that hold the fittings in place. HTH,

(and no more snickering about my explanation of thermodyanmics!)

 

". . . and no more snickering about my explanation of thermodyanmics!"

You have to admit, it was the long way to say air-cooling. I like the new word, though. Adiabatic. Sounds Greek.

 

I haven't heard that word since I got my degree.

As a side note, replace the crush washers. They are a one time use only and I think people trying to reuse them and stop the leaks, by over tightening, is one of the major reasons the bungs crack on the FMOC. I know i've made them worse that way before I knew better.

 

Thats more likely the culprit than the hoses. It can be repaired though if thats the case.

 

Your too smart to be here with us fools ya know.

 

I don't want to steer this thread away from it's intended path so I'll be really brief. The term adiabatic refers to an ideal type of work where there is no energy loss due to heat dissipation. It really doesn't have any meaning in what you're describing.