Oil Leak (How Serious)

[C J R]

Hi,
Third day of owning my new Rex and I noticed a few drips of oil on the garage floor. Investigated and can norrow the source down to the area around the back of the Sump (near the cross member) where the engine joins the gearbox.
Looks like some sort of gasket goo (grey in colour) was used to seal the sump.
As I have just found the leak, I haven\'t monitored how much loss there is, but it has produced a light oil covering on the gearbox casing.
I hope the attached picture can help with my description.
 
Questions;
What kind of job is it to remove the sump and fit a gasket ?
If the leak is slight, can I run the car, monitor oil usage and complete the repair later ?
 
Thanks
Chris

[interloper393]

from what iv read changing the sump gasket it a mare off a job and most remove the engine to repace, dont quote that tho but im pretty sure thats the case..

[C J R]

That\'s what I suspected
 
As the car is for weekend use, I\'ll have to decide whether to run the car through the summer and tackle the sump as a winter project (providing the leak does not get worse).

[Jit]

if the oil is on the bottom of the bellhousing, then id have thought you might have a leaky rear main seal rather than a leaky sump. If its the main seal, i would get it done asap. While youre there, you may as well do a clutch change if its getting close to one and maybe a flywheel upgrade if youre feeling flush!
If it is the sump, you need to lift the engine off its mounts to remove and re-seal it. it doesnt have to come out.

[davehg]

as jit says, its most probably the rear main oil seal, these are only about 10 pounds but you need to take the gear box out and fly wheel/clutch off to replace it.

[m1tch]

Hmm but if the leak gets worse and the rotors are staved of oil thats gonna cost you a bit more to fix....Also as the oil gets hotter it becomes thinner so easier to leak, so that stuff on your garage floor is what leaked when the oil was thick and not very fluid...meaning you are probably losing lots more when it warms up and driving

[pete sparrow]

I\'d clean the block/sump/gearbox off with some de-greaser and then run the car up to warm and check again.
Had the same small amont of oil dripping exactly at that point on my car and it turned out to be the omp line that fed the rear rotor. If not cured quickly the rear rotor could throw a tip or worse!
The omp lines can be traced back from the oil metering pump.They run along the top of the block and are made of brittle plastic.

[C J R]

Thanks Guys,
I\'ll do some more investigations.
Chris

[Nik da Greek]

I\'d clean the block/sump/gearbox off with some de-greaser and then run the car up to warm and check again.
Had the same small amont of oil dripping exactly at that point on my car and it turned out to be the omp line that fed the rear rotor. If not cured quickly the rear rotor could throw a tip or worse!
The omp lines can be traced back from the oil metering pump.They run along the top of the block and are made of brittle plastic.

I had similar troubles to this, only it was the OMP line to the front rotor! The alternator had crimped and chafed through the line where it was wrongly routed. The problem was masked by the fact that the sump gasket was leaking, too, which I knew about, so wasn\'t too worried, since I was planning to get it fixed as and when. Could have been a disaster, glad I got the work done when I did and the more sinister fault was found. Definitely worth tracing the exact origin of your leak if you can!

[C J R]

As I am new to the RX7 can anyone point me in the right area to identify the oil metering pump and OMP pipes.
Thanks
Chris

[pete sparrow]

As I am new to the RX7 can anyone point me in the right area to identify the oil metering pump and OMP pipes.
Thanks
Chris

Are you running standard twin turbos?? If so it makes the job slightly more complicated i\'m afraid.
They run along the top of the block under the phelnum. You\'ll have to remove the phelnum,throttle body and ducting to be able to have a proper look.
Be very careful when removing the phelnum because of all the solinoids and vac hosing attached,best bet is to do a diagram of where everything fits.
The omp lines sit very close to the block and should be made of clear plastic stained an oily colour. Some of the line might have black heat shrowd around it.
They\'ll be hiden amongst some of the wiring loom so be very careful when trying to dig them out as they are soooooooooooooooo brittle!!!
Both the omp bango connection sit on top of the front and rear rotor housings.
Look down at the l/h side of the block,behind the manifold and under the fuel line you\'ll see the  omp line for the rear housing. You will have to remove the fuel line to get a good look at the omp bango connection.Fuel will spill so be ready with a cloth!
The front omp bango connection is slightly easier to locate and check.
Definately check them both both at the bango connecters and trace them back to the omp pump which is on the r/h front side of the engine.
If you find a split or leak,do not use your car!!! If you do,you might cease a rotor or throw a tip!!!!:mad:
I was lucky mine cracked right by the bango connection,so i was able to shrowd the end and do a temp repair.
Got my metal braided line on now so no chance of that happening again.
No specialist tools required,justa small socket set,spanners and long alan keys.
Not a 5 min job,expect the job to take a good few hours.
Hope this helps.

[C J R]

Many thanks Pete, this is why I like joining clubs like this.
 
I\'m running a single turbo, so some of the solenoid issues might not fully apply, but I get the gist of what you recommend.
 
I do recall looking up (from under car) and seeing a banjo connection to the block (the same side as the starter motor) but it did not appear that was where the main source of oil was coming from, but based on your information I will carryout a thorough check on all the oil pipes.
 
The reason I was drawn to the sump was the obvious grey mastic/sealant used to seal which had not done a good job, so I will still have to seal the sump.
 
If I lift the engine straight up to drop the sump, do you know if there is sufficient clearance around the tunnel to leave the gearbox attached to the engine, provided I remove the propshaft/gear stick and engine ancillaries ?
 
Thanks
Chris

[pete sparrow]

Hi Chris.
Doubt very much you saw the omp bango connection from the underside as they are placed near enough on top of the block itself,but i might be wrong.
I don\'t think you could investigate the problem from under the car,you\'ll have to do the work from the top.
Lucky your running a single mate,that\'ll save a load of time:D
Once the phelnum is out of the way you can pretty much see everything you need to.
I\'d honestly check both omp lines just for peace of mind.

Can\'t answer the question about dropping the sump,but i know a man that can.So i\'ll get his advice and post an answer later for you.

[Nik da Greek]

The OMP lines are a sort of weird browny plasticky stuff, only a few mil in diameter, with metal banjos crimped on the end. They used to use the same stuff on old Brit bikes for external oil lines, and like Morris Marinas and stuff. I think it\'s supposed to be flexible, so it can be shaped to the contours the line has to follow and then hardens off when heated by use. Sometimes seem to harden off too much and go brittle, is the downside. Definitely a good idea to replace with braided steel or something if possible

[nikp]

I had to replace one of mine becuase it was so brittle. I have a brand new plastic one - it is moulded to shape from new. Anway, thew OMP lines go to the OMP at the front of the engine on the drivers side, just above the sump. Should be easy enough to spot on a single.

If you have an engine crane, you shouldn\'t have to remove many bits to raise the engine enough to replace the sump sealent. By the way, the grey stuff is Mazda Sump Sealent, a type of silicone sealent instead of gasket. It\'s a very good sealent in actual fact.