Oil pulling on the top of the engine underneath where the carburetor sits
 

Good morning, in trying to get the car ready to pass smog I've noticed where my burning oil smell is coming from. There is a pretty good oil leak on the top of the engine somewhere that is resulting in oil pulling under where the carburetor sits. It isn't doing in a Texas gusher style fountain of oil, but it is wet and some oil will actually pool so it's a considerable leak.

Could I ask for some coaching on where that might be coming from, and how serious it is? I do understand that the dowel pins is a full rebuild the category, but not sure if this is symptomatic of that. I don't have much history on the car, the odometer shows 22,000 miles, which I believe is 122. The engine does not smoke otherwise and runs smoothly with what feels to me to be decent power.

Thank you in advance for the help!

I would check two things, first check your oil cooler seals (bee hive) and then check your OMP lines.

Good morning and thanks for the note. Just trace the oil cooler lines back, wipe the attachment points clean and then see if I get leaks? OMP = oil metering pump, correct?

I would do that, and also look at the base of your oil cooler. Is this a 12a or a 13b? If it is a 12a the oil filter will screw into the top of it.

OMP is the oil metering pump.

check the omp lines where they connect to the carb. one or both may have detached from the carb. these lines flow a very small amount of oil so it would take a little time to notice it.

Thanks guys - really appreciate the help.

It looks like one of the clear plastic tubes is disconnected from the carb.

https://cimg5.ibsrv.net/gimg/www.rx7...89048dba78.jpg

The OMP lines are suppose to have little clips on them.

Well that might explain why it came off!

Neither of my lines do, would Mazda still have these or just use a hose clamp?

I very much appreciate the help-I'm trying to press her back in the regular use because she has a fantastic car, but you know how that goes ...

I'm not sure if the factory ones are available. They are pretty simple. I'd just use spring clips.

I don't know the exact size, but the factory ones look like this.

Just push it back on. See how well it fits.

Thanks for the help guys.

Good news - those lines have stayed plugged in.

Bad news - just as much oil pooling below the carb still.

It appears the leak is from elsewhere.

My oil cooler lines terminate on the driver side bottom, so that is not it.

This is a 12a, sorry for not indicating that earlier.

Clean the area very good then monitor where the source is. Once it's clean it should be a little easier to identify.

Another trick after it is clean would be to wad paper towels up and place all along that area. Then look for the paper towels that have oil after driving it.

I couldn't be a dowel pin leak on that side of the engine, under the carb.

Thanks for correcting my mistake. I've edited my answer.

Appreciate the help and ideas.

Checked that area again and it oil. Oil metering lines are dry, not leaking.

It could be a slight coolant leakage from intake gasket that is getting dirty. I had same problem and noticed that liquid looked like oil but was very watery. If its is coolant just need to replace the two small coolant seals and intake gasket. You could also install freeze plugs in place of small coolant seals.

My OMP lines would slide on and with little pull come right back off. They did leak.
I finally put hose clamps on.

Looking at Tdskp's picture the vacuum lines do look a bit wet, but that may just be the photo.



https://cimg5.ibsrv.net/gimg/www.rx7...03efebd248.jpg