Puzzling Oil Leak

[Zedrally]

Hi all,

I have a puzzling oil leak in the L24.

Bear with me and if you have any input don't be afraid to post.

Gradually over a period of 12 months, I've noticed a small buildup of oil, over the past 2 months it's become more than a slight drop here and there, so over the xmas break I decided to do some indepth investigation.

2 weeks ago, armed with a high pressure spray unit, I cleaned down the whole RHS of the block, including the fuel pump and front timing chain cover so I would be able to observe and trace the source of this leak.

Conclusion/deduction from last weekend was,

Oil was not dripping from.

Front cover

Cam cover/gasket.

This left only the fuel pump gasket, which after cleaning up the area seemed to be the source of my problem.

Not having a spare gaskets. I decided to remove the pump and inspect the soundness of the gaskets, which after cleaning they appeared OK, but had been tensioned down. To see if it was a gasket problem I replaced the pump and gasket using a thin film of silicon, let it hardened and tensioned the assembly.

Feeling like I solved the problem I shouted myself a rum or 2 and patted myself on the back.

After using the zed yesterday, I re-checked the block and to my shock it was dropping more oil than before.

I'm convinced it's located in the fuel pump region and am wondering if anyone has experianced a crack in the casting or similar that would cause this.

The only way I have of testing this theory is a new pump, but why replace something that isn't broken!

Any ideas out there.......

[2-4-T-Z-MAN]

You might find that a used gasket will just leak. A thin film of silicon can be used on each side of a gasket to help seal and hold the gasket in place, but not as a gasket itself. Oil preasure will find the weakest point and leak. If yo have a hard time finding a proper gasket, just purchase some gasket material and cut your own.

Good luck.

[Ed]

There is a chance that it is the fuel pump itself. If you look at the internals of the fuel pump you will notice that oil gets splashed into the lower half of the pump up to the diaphragm. On an old pump of mine the diaphragm wasn't sealing with the lower portion of the pump. Confused? If you take the fuel pump apart you will notice a round rubber diaphragm. When it gets old it won't seal the two halfs of the pump anymore allowing it to leak oil.

[Zedrally]

Would it be possible that the bushing of the pivot on the pump is worn and causing this?

Looking like a new pump, isn't it!

[LanceM]

I'm with Ed, probably the fuel pump that is leaking, and maybe the gasket too. A bad fuel pump can pump a lot of gas into the oil too!!!

[Zedrally]

That would explain why I've been noticing a slight smell of gas.....

Thanks all, should I go OEM or would an AM pump be just as good?

[LanceM]

A fuel pump is one of those "so simple" items that you would think anyone could make it and make it well, but the problem is if it isn't right and it pumps your crankcase full of gas, well gas and oil mix well, gas and bearings don't.... I'd spend the $ for an OEM, just cause.....

[Zedrally]

Addendum:

I've just sealed the hole where the pivot goes.

No oil leak.

I can't see how the diaphram could be damaged as this would only result in gas being pumped into the crankcase, rather than oil appearing on the side of the block, rear of the fuel pump.

I guess I'll run carefully over the next few days just to be sure...

MOM

[Bambikiller240]

I can't see how the diaphram could be damaged as this would only result in gas being pumped into the crankcase, rather than oil appearing on the side of the block, rear of the fuel pump.

Not necessarily. At one time I had oil lightly spraying out of a small hole (manufacturer provided) on the underside of the fuel pump. It caused a mess on the front of that side of the engine. The crankcase oil never smelled like gas (I have experienced that before, on another car, a Toyota) at all.

Not sure how you sealed the pivot, but unless the seal is extremely flexible, and durable it's not likely to last. I don't know how expensive a fuel pump is in OZ, but you might still be needing one eventually.

Like you said, best to keep an eye on it.

[Zedrally]

Thanks to all that replied.

For the record....

The pivot hole was cleaned of all visable oil and de-greased.

I used silicon sealant to plug the hole.

An OEM pump in Aus is $171.84 +GST =$189.03

AM = $117.30 +GST=$129.03

OEM is 3 day delivery AM 1 day.

Wonder if there is a repair kit?

MOM

[beandip]

Do you have any RX-7. in oz? If so see if you can find a early '80 and pull the electric pump. Here from a bone yard they are around $15.00 and will work really well. Then just block off the port in the head. They pump 4psi.

[Zedrally]

Do you have any RX-7. in oz? If so see if you can find a early '80 and pull the electric pump. Here from a bone yard they are around $15.00 and will work really well. Then just block off the port in the head. They pump 4psi.

Another good idea.

Thanks....