(ENGINE) Interesting dowel pin oil leak fix.
 

I found this fix for the dowel pin oil leak on the 12A motors while searching the internet on the problem. I am going to try it on my car this weekend. Currently I have to add 1 qt of oil every 400 mikes or so because of the oil leak. I will let you all know how it turns out. Below is the description of the fix as copied from the link (spelling and grammar corrected by me). :)



Thought I would share this fix I used for many years when you have a motor with the common oil leak at the top dowel between rotor housing and end plate

This fix lasted me for 9 years after I purchased this motor cheaply second hand because of the oil leak. It looks and sounds bodge but hey it saves stripping the motor to replace a 2 dollar o ring which ends up costing you a minimum $170 for the full o ring kit plus labor.

Tools needed

1. Small hammer
2, Center punch
3. Very small drill bit...0.5-1mm
4. Equally small self tapper
5. Syringe
6. Compressor with blower attachment
7. Thinners
8. Permatex, silicone or any type of liquid gasket stuff
9. About 1 hr of your time maximum

It involves doing some careful measuring first so here goes.

1.About 2.5mm from the offending end plate that leaks center punch ...(the original area is 2-2.5mm) thick so the drill will work into the o ring area.

2.Drill the small hole straight down till it bottoms into dowel area.

3.Fill syringe with thinners and inject thinners into the drill hole till it squirts out of the dowel location.

4.Blow through with compressed air via blower attachment. You will see goo blowing out of that top corner of the dowel location.

5.Now fill the syringe with Permatex or other sealant stuff and pressure inject into the hole. I did this about 3 times forcing the sealant in with compressed air and each time refilling the hole with gasket goo using the syringe.

7.Cap off the hole with a self tapper screw.

The motor did die eventually but only after 9 years of hard thrashing and abuse.....nothing to do with this fix..

I can at least now show you how it worked as the motor is now in bits where you can see how it actually works. The picture is of the front housing where the leak was under the distributor and the screw was barely noticeable.....some nubie tried to seal it with liquid metal (didn't work) from the outside which I had to try and scrape away first.

Here is the link to see picture

docs.google.com/Doc?docid=0AVO4SLhkmev6ZGhzbXc5N2ZfNjN4eDZiOWh3OA& hl=en

Sounds interesting. Please keep us posted on your results. :)



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Cool! Now if only chipped side seals were as cheap to fix, I'd be in business.

OK I got a chance to try the fix Friday night. I drilled the hole using a 1/16" drill bit and I used Radio Shack canned air to force in the sealant instead of a air compressor because I did not have a air compressor. The sealant I used was Prematex ULTRA BLACK gasket maker.

The drilling went OK. I drilled just left of the "M" in Mazda. I knew I had drilled far enough as the drill seemed to meet a lot less resistance when it hit the dowel area.

I cleaned out the hole by injecting some paint thinner into it with the syringe and forcing it in with canned air.

I then filled the hole with gasket maker using the syringe and forcing it in with the canned air. I repeated this step about 7 of 8 times.

I then filled the hole with gasket maker one last time and then screwed the screw into the hole. Total repair time about 45 minutes.

I let the car set overnight without running the engine to let the gasket maker set up and this morning took the car out for a 20 mile drive to test if the repair worked.

The verdict at the end of the drive after opening the hood and checking for leaks was NO OIL LEAKAGE coming from the dowel pin area and no oil dripping down the side of the engine on to the ground :lol:

This same drive before the fix would have produced a puddle of oil on top of the engine by the MAZDA 12A with oil running down the side and dripping on the ground.

So far I am very happy. I will post updates as I drive the car to and let everyone know if the fix holds up. Total cost for the fix was 15.00 bucks for the gasket maker and 9.00 bucks for the canned air.

fantastic im glad it worked out for you! id still wanting to know the long term!

u sir are a god send!!! im so sick of the oil burning off the car and coming into the cabin from the transmission. i swear several times a week people tell me that my car is on fire. is there any way you could take a photo???? im a little sketched on trying it and would like to see exactly where u drilled. thanks for the amazing post. -noel

Dude, there is a reason Mazda makes the 12A leak oil there, you're messing with the balance of the whole freaking universe.

Brilliant though, I'm going to lock that one away for future use.

Great tip - if it works!!
PLEASE keep us posted so we know it works.
Thanks for taking the time to share. My SA has a slight, annoying leak which I wrap a "diaper" around, so this would be sweet...

Stu Aull
80GS
Alaska

he posted a link in the 1st post

http://docs.google.com/File?id=dhsmw97f_64cr7bqtgs_b

Cool, you might change the oil though, depending on how much paint thinner you put in, cause thinner can be really bad for all the other o-rings. Just a thought.

For those that asked where I drilled the hole here is a picture of the location of the screw.

http://docs.google.com/File?id=dhsmw97f_66hfm24smh_b

If you notice to the right of the screw in the valley there is a tiny amount of oil leakage. This is the only leakage so far. Before the fix there would be a flood of oil coming from there and from the seam by the screw. So I would say 95% fixed.

two more questions,

-do u think that JB WELD would work instead if the self-tapping screw??
-and what do u need the compressed air for would the plunger from the suringe work? or is it for when the gasket maker is already in the hole???

i just went and bought all the supplies to do this project so i should be attempting it next week on my days off, and ill post the results.
thanks-noel

This should be archived; right next to my five minute coolant seal repair method. :)

The compressed air is used to force the sealant into the dowel area. You use the syringe to put sealant into the hole and then use the compressed air to force the sealant into the dowel area. Use a fitting that covers the hole area so you do not blow the sealant out of the hole. You want to force sealant in to the dowel area.

Remember to drill straight down. There maybe some clearance issues with the drill depending in the drill used.

I used a can of compressed air. A 100 PSI air compresser would work better and may allow you to force more sealant into the area as it has more pressure.

I thought of JB weld but used the screw instead. If you use the screw remember to fill the hole with sealant before capping off the hole with the screw. This will prevent leakage from around the screw.

Also Permatex makes a product called stop leak. It is a spray you spray on to the engine to stop low pressure leaks . I have put some on the seam area that is seeping a little oil. I will post my results using this also.

Good Luck

I KNOW, i'm ducking just in case....

im gonna talk my wife into letting me get the supply for this either today or tomorrow and give it a shot. thanks!

so how did you pinpoint the exact spot that your engine was bleeding from?

I wiped away all the oil from on top of the engine. I then started the engine and looked at where it was seeping from.

Where I drilled was where the the dowel pin o-ring is located. Look at my link to the first picture I posted. The guy who came up with the idea showed what the o-ring and where it is looks like.

Put a lot of sealant in. Use a air compressor if you can. You only have one shot at it. I have a small amount of seepage still but still much much better than it was. If I had used a compressor I probable could have shoved more sealant in and completely stopped the leak.

If it does not work for you... well you had a oil leak before you started :)

so i tried this last weak, drilled into the motor with a 1/16" drill bit and then the seringe that i had was too big so i ended up squrting the gasket sealant onto of the hole and then using a sewing needing to shove it in. I blasted it with the air compressor and repeated several times hoping that it would work. I then took a spare rotor housing and took the two self-tappers that i bought and measured them to see if they would work, and both of them would have gone too far and ended up going through the dowel pin itself so i decided to use JB Weld instead. Well i'm happy to say a week later and there has been no leaks and only a small amount of smoke from whats already coating the underside of the car, the oil level has stayed steady. So thank you again for posting this idea up on the board it defiantly works and doesnt take more than an hour to do. appricate it -Noel

Glad to hear everything worked for you. :lol:

This really needs to be pinned to the top or archived so we all can use this method when needed.

While using the search engine would easily bring up the thread, I want to get one more set of "reports" from the guys who have done this by the end of next month. Heck, I'm going to do it myself since tightening the screws around the dowel pin didn't quite work as well as it should have. After they chime in, I'll clean up the thread and it's going into the FAQ thread with its own "Is there a cure for the oil leaking out of the top of my engine? YES! It's called the 'Dowel Pin Oil Leak" and here's the answer!"

:cool:

I decided to post an update on the dowel pin oil leak fix and how it is holding up in my car. I finally had to add a quart of oil to my car after 2520 miles. Before the fix I was adding a quart of oil every 300 miles or so because of the leak. The fix is holding up great.