12a Rebuild: Oil Leak - front most dowel pin O-ring
10-05-14, 09:08 PM
#1
12a Rebuild: Oil Leak - front most dowel pin O-ring
It runs great. Way better than before.
Needless to say, I'm not a happy camper at the moment.
I cleaned off the left side. Put lots of light on it. Ran for a few minutes and there it was: a small but steady flow from the area of the front most dowel pin O-ring.
Went out, got some gas at $3.12 and drove around for awhile as a consolation.
Options:
1. Monitor the loss. As I only really drive it for fun and 10 miles to work, if the loss is manageable, I might just live with it.
2. Replace the O-ring. Not my first choice. May be necessary if the flow is excessive and cannot be managed.
3. ???????
Needless to say, I'm not a happy camper at the moment.
I cleaned off the left side. Put lots of light on it. Ran for a few minutes and there it was: a small but steady flow from the area of the front most dowel pin O-ring.
Went out, got some gas at $3.12 and drove around for awhile as a consolation.
Options:
1. Monitor the loss. As I only really drive it for fun and 10 miles to work, if the loss is manageable, I might just live with it.
2. Replace the O-ring. Not my first choice. May be necessary if the flow is excessive and cannot be managed.
3. ???????
10-05-14, 09:52 PM
#2
I had one that did that once. Turned out an o-ring fell on the floor and I didn't catch it until the engine did exactly what yours did. Moral: don't oil the o-rings before installation in the rotor housings. Some instructions recommend you do. Nope. Not for me. I now install them dry and not a leak or lost o-ring since. Even on beehive engines.
10-06-14, 04:29 AM
#3
So the Q:
is it MISSING, or there and leaking. My 60Kmi SA leaked there when I got it, thru in a can of NoLeak in and it reduced the flow to a weep. That was 5 yrs ago… beat a tear down - so nothing lost in trying?
There is also a technique of drilling a small hole into the housing at the dowel and injecting a sealer. I do not have the details but maybe someone does. It does work apparently, if you have the stomach for punching a wee hole in your housing to try it.
Sorry for your troubles…
Stu Aull
80GS
Alaska
is it MISSING, or there and leaking. My 60Kmi SA leaked there when I got it, thru in a can of NoLeak in and it reduced the flow to a weep. That was 5 yrs ago… beat a tear down - so nothing lost in trying?
There is also a technique of drilling a small hole into the housing at the dowel and injecting a sealer. I do not have the details but maybe someone does. It does work apparently, if you have the stomach for punching a wee hole in your housing to try it.
Sorry for your troubles…
Stu Aull
80GS
Alaska
10-06-14, 05:37 AM
#4
I searched my memory.
I don't know if its possible but it may have shifted and I caught it with the dowel pin.
I used Hylomar to glue them in place.
The No-Leak seems a good place to start. Weeping would be acceptable.
Thanks for the input.
I don't know if its possible but it may have shifted and I caught it with the dowel pin.
I used Hylomar to glue them in place.
The No-Leak seems a good place to start. Weeping would be acceptable.
Thanks for the input.
10-06-14, 02:35 PM
#5
Hylomar would be the problem. They're supposed to go in dry.
Don't use magic potions on a fresh rebuild. The leak isn't from age. It's from a mistake during assembly or a nick/damaged metal in the iron or rotor housing. Or a missing o-ring. Or maybe the hylomar goo displaced the o-ring causing it to pooch out and got pinched.
Don't use magic potions on a fresh rebuild. The leak isn't from age. It's from a mistake during assembly or a nick/damaged metal in the iron or rotor housing. Or a missing o-ring. Or maybe the hylomar goo displaced the o-ring causing it to pooch out and got pinched.
10-06-14, 03:00 PM
#6
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i bought an FB once where the previous owner had mixed up a dowel oring with the oil filter/oil cooler o ring, and it leaked.
maybe this is you? not much consolation...
maybe this is you? not much consolation...
10-06-14, 04:07 PM
#7
If it's any consolation, Tim, the two-time first place RX-7 winner at JCCS has shown up both times with a clear dowel-pin leak on his front iron. Hasn't stopped him from showing, winning, or driving his turboed monster.
I've used a light smear of hylomar on the 'bottom' dowel pin o-rings on each of three builds. None ever leaked a drop, so it's not necessarily the hylomar at fault. Could be several things, as Jeff listed.
I've used a light smear of hylomar on the 'bottom' dowel pin o-rings on each of three builds. None ever leaked a drop, so it's not necessarily the hylomar at fault. Could be several things, as Jeff listed.
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10-06-14, 07:44 PM
#9
I searched through the bags of used parts, nothing there.
The only O-rings not used were extra intake manifold water jacket O-rings I bought thinking that was the original issue, and the small one that goes on the thermal pellet which I don't have.
I also searched the "clean" workspace I used during the assembly. Nothing there.
The O-ring is in there.
I need to think about this. Yes the "best" solution is to rebuild.
I don't drive it once the roads get salted. I may only have 5 more weeks I can drive it then its in the garage until 3 heavy rains after the last salting, and that comes around the end of March.
So, if I do decide to rebuild again, I have the time and it will go much quicker as everything is cleaned and speced. And I have a much better idea what I'm doing.
I do want to see if I can stem the flow externally. I have the cleaned previous rotor housing I'm using as a bookend. The leak is not to the top, but out to the side. On the prior housing there appears to be a slight indication the iron did not make full contact in that area. It just looks different. I want to clean the leaking spot and see if there is a measurable gap which I might be able to fill.
I also want to measure the amount of oil it is loosing by running it at 2K for 15 minutes and catching what runs out. It always drips off in the same location.
I was careful, just not experienced.
The only O-rings not used were extra intake manifold water jacket O-rings I bought thinking that was the original issue, and the small one that goes on the thermal pellet which I don't have.
I also searched the "clean" workspace I used during the assembly. Nothing there.
The O-ring is in there.
I need to think about this. Yes the "best" solution is to rebuild.
I don't drive it once the roads get salted. I may only have 5 more weeks I can drive it then its in the garage until 3 heavy rains after the last salting, and that comes around the end of March.
So, if I do decide to rebuild again, I have the time and it will go much quicker as everything is cleaned and speced. And I have a much better idea what I'm doing.
I do want to see if I can stem the flow externally. I have the cleaned previous rotor housing I'm using as a bookend. The leak is not to the top, but out to the side. On the prior housing there appears to be a slight indication the iron did not make full contact in that area. It just looks different. I want to clean the leaking spot and see if there is a measurable gap which I might be able to fill.
I also want to measure the amount of oil it is loosing by running it at 2K for 15 minutes and catching what runs out. It always drips off in the same location.
I was careful, just not experienced.
10-06-14, 09:34 PM
#13
talking head
thinks if you havent run too far you could jig the rear together
and lift it up that front plate and housing
and at the worst replace just those water seals and the dowel rings
BTW... i have had no issue with the hylomar
.. or deliberately using the 15.8 x 2.4 cs o ring ( the same size as oil filter pedestal ) on plenty of engines
the original is 1.9 by 17.8 ish and floats with its OD near the edge in the land with plenty of spare ID around the dowel
and it is prone to fall out when flipping a housing up unless gooped with vas or hylomar
( note .. 1.9mm cs at larger than 8.8 mm ID is an odd size to find in JIS standard kits and the common kit 2.4 mm cs at 17.8 certainly will not fit )
while the 15.8 x 2.4 mm fits snug over the dowel and will never fall off
and with plenty of space left around the land for it to compress into
it is easier to fit casue you can have it snug on the dowel before you place the housing
and with no worry about it being central
it may also be a better option ( no fails for me yet ) if everything is not so straight anymore.. works for me
i think the error here is it is forgotten..
or lost when flipped up
or was caught when the dowel was pushed through
none of these will be fixed with goop
i think the rooky mistake was to put the dowel in last
and maybe to not take a pic at each step,, as it sure helps with the late night worry later
and lift it up that front plate and housing
and at the worst replace just those water seals and the dowel rings
BTW... i have had no issue with the hylomar
.. or deliberately using the 15.8 x 2.4 cs o ring ( the same size as oil filter pedestal ) on plenty of engines
the original is 1.9 by 17.8 ish and floats with its OD near the edge in the land with plenty of spare ID around the dowel
and it is prone to fall out when flipping a housing up unless gooped with vas or hylomar
( note .. 1.9mm cs at larger than 8.8 mm ID is an odd size to find in JIS standard kits and the common kit 2.4 mm cs at 17.8 certainly will not fit )
while the 15.8 x 2.4 mm fits snug over the dowel and will never fall off
and with plenty of space left around the land for it to compress into
it is easier to fit casue you can have it snug on the dowel before you place the housing
and with no worry about it being central
it may also be a better option ( no fails for me yet ) if everything is not so straight anymore.. works for me
i think the error here is it is forgotten..
or lost when flipped up
or was caught when the dowel was pushed through
none of these will be fixed with goop
i think the rooky mistake was to put the dowel in last
and maybe to not take a pic at each step,, as it sure helps with the late night worry later
10-06-14, 09:53 PM
#14
thinks if you havent run too far you could jig the rear together
and lift it up that front plate and housing
and at the worst replace just those water seals and the dowel rings
BTW... i have had no issue with the hylomar
.. or deliberately using the 15.8 x 2.4 cs o ring ( the same size as oil filter pedestal ) on plenty of engines
the original is 1.9 by 17.8 ish and floats with its OD near the edge in the land with plenty of spare ID around the dowel
and it is prone to fall out when flipping a housing up unless gooped with vas or hylomar
( note .. 1.9mm cs at larger than 8.8 mm ID is an odd size to find in JIS standard kits and the common kit 2.4 mm cs at 17.8 certainly will not fit )
while the 15.8 x 2.4 mm fits snug over the dowel and will never fall off
and with plenty of space left around the land for it to compress into
it is easier to fit casue you can have it snug on the dowel before you place the housing
and with no worry about it being central
it may also be a better option ( no fails for me yet ) if everything is not so straight anymore.. works for me
i think the error here is it is forgotten..
or lost when flipped up
or was caught when the dowel was pushed through
none of these will be fixed with goop
i think the rooky mistake was to put the dowel in last
and maybe to not take a pic at each step,, as it sure helps with the late night worry later
and lift it up that front plate and housing
and at the worst replace just those water seals and the dowel rings
BTW... i have had no issue with the hylomar
.. or deliberately using the 15.8 x 2.4 cs o ring ( the same size as oil filter pedestal ) on plenty of engines
the original is 1.9 by 17.8 ish and floats with its OD near the edge in the land with plenty of spare ID around the dowel
and it is prone to fall out when flipping a housing up unless gooped with vas or hylomar
( note .. 1.9mm cs at larger than 8.8 mm ID is an odd size to find in JIS standard kits and the common kit 2.4 mm cs at 17.8 certainly will not fit )
while the 15.8 x 2.4 mm fits snug over the dowel and will never fall off
and with plenty of space left around the land for it to compress into
it is easier to fit casue you can have it snug on the dowel before you place the housing
and with no worry about it being central
it may also be a better option ( no fails for me yet ) if everything is not so straight anymore.. works for me
i think the error here is it is forgotten..
or lost when flipped up
or was caught when the dowel was pushed through
none of these will be fixed with goop
i think the rooky mistake was to put the dowel in last
and maybe to not take a pic at each step,, as it sure helps with the late night worry later
I have 100's of pics taking it apart, but nearly none putting the stack back together. Never occurred to me I would need them now.
Lessons learned.
Thank you.
10-06-14, 11:19 PM
#16
... but chin up, Tim. as Bumpstart also said, at least you know you can build an engine that runs ... and runs well! i hope i don't sound patronizing, but you did a good job your first time out and i hope you don't lose sight of that. these things happen.
i know a few guys around the board have built engines from the rear forward, so there has to be a way for you to "fix" this if you carefully pull the front.
you probably could live with the leak. i have lived with oil leaks and coolant leaks in long term situations, but the reason i'm fairly sure i would not live with this in this situation is because it's a fresh rebuild, not an engine with years and miles behind it (well, not really, but you know what i mean
)at the end of the day, it's your decision though my perspective may be irrelevant, and that's fine too.
10-07-14, 08:16 AM
#18
Thanks everyone.
Reality check: Its not a drip, its not a leak, its a flow.
I'm not driving it that way and the only real fix is to replace the O-ring. Missing or crushed, its still the same solution.
I've too much invested to not get it right.
Tonight I'll drain its bodily fluids and start stripping off all the external pieces.
Yes, I did rebuild it and make it run better than at any time since I've had it. Thanks for reminding me.
I now have all the tools I need, no more shopping.
The sequence is still fresh in my head.
And everything is still fresh and clean to work on. It has only run for a little more than an hour total.
I want to get it done before winter so I need to get started.
Thanks again.
Reality check: Its not a drip, its not a leak, its a flow.
I'm not driving it that way and the only real fix is to replace the O-ring. Missing or crushed, its still the same solution.
I've too much invested to not get it right.
Tonight I'll drain its bodily fluids and start stripping off all the external pieces.
Yes, I did rebuild it and make it run better than at any time since I've had it. Thanks for reminding me.
I now have all the tools I need, no more shopping.
The sequence is still fresh in my head.
And everything is still fresh and clean to work on. It has only run for a little more than an hour total.
I want to get it done before winter so I need to get started.
Thanks again.
10-07-14, 08:27 AM
#19
Tip on taking off the carb/intake/rats next. If you unbolt the intake manifold from the engine and remove the two bolts that hold the rats nest in place you can take the entire assembly off as one piece.
Another thing I do is to not unbolt the thermostat neck from the water pump housing and just remove the water pump bolts from the front cover.
Good luck in the re-rebuild. It's the right choice.
Another thing I do is to not unbolt the thermostat neck from the water pump housing and just remove the water pump bolts from the front cover.
Good luck in the re-rebuild. It's the right choice.
10-07-14, 09:45 AM
#20
talking head
you can jig the engine with strips of flat bar drilled appropriately along either sump holes, or inlet studs or along the top of the engine / housings
that will allow you to draw the through bolts and flip engine up to separate the front plate
( or the front plate and the front housing )
all without releasing too much tension on any of the rest of the stack and risking those water seals
the rear bolt seals you can give a lick of silicon and re-use if they are fresh
the inner water seals may be OK. but personally i would replace it
the outers most certainly will jump out and be stretched and need renew
you can pressure test it while together with inlet manifold
by leaving off the water pump housing and replacing it with a flat plate with a fitting for an airline
( fill it with water and connect up airline to 15 psi )
to allow you to look inside for leaks and check the rear bolt sealing
that will allow you to draw the through bolts and flip engine up to separate the front plate
( or the front plate and the front housing )
all without releasing too much tension on any of the rest of the stack and risking those water seals
the rear bolt seals you can give a lick of silicon and re-use if they are fresh
the inner water seals may be OK. but personally i would replace it
the outers most certainly will jump out and be stretched and need renew
you can pressure test it while together with inlet manifold
by leaving off the water pump housing and replacing it with a flat plate with a fitting for an airline
( fill it with water and connect up airline to 15 psi )
to allow you to look inside for leaks and check the rear bolt sealing
10-07-14, 07:02 PM
#21
you can jig the engine with strips of flat bar drilled appropriately along either sump holes, or inlet studs or along the top of the engine / housings
that will allow you to draw the through bolts and flip engine up to separate the front plate
( or the front plate and the front housing )
all without releasing too much tension on any of the rest of the stack and risking those water seals
the rear bolt seals you can give a lick of silicon and re-use if they are fresh
the inner water seals may be OK. but personally i would replace it
the outers most certainly will jump out and be stretched and need renew
you can pressure test it while together with inlet manifold
by leaving off the water pump housing and replacing it with a flat plate with a fitting for an airline
( fill it with water and connect up airline to 15 psi )
to allow you to look inside for leaks and check the rear bolt sealing
that will allow you to draw the through bolts and flip engine up to separate the front plate
( or the front plate and the front housing )
all without releasing too much tension on any of the rest of the stack and risking those water seals
the rear bolt seals you can give a lick of silicon and re-use if they are fresh
the inner water seals may be OK. but personally i would replace it
the outers most certainly will jump out and be stretched and need renew
you can pressure test it while together with inlet manifold
by leaving off the water pump housing and replacing it with a flat plate with a fitting for an airline
( fill it with water and connect up airline to 15 psi )
to allow you to look inside for leaks and check the rear bolt sealing
I'll come back to this when I get it out.
Thanks for your wisdom, experience and help.
10-10-14, 10:18 AM
#25
I put a numbered post-it next to each bolt for the sequence and progressively went around till I reached the correct torque spec.
But..............
I should have the engine out tonight or at least by Sunday. And I can recheck before I open it back up.
Excellent suggestion.
But..............
I should have the engine out tonight or at least by Sunday. And I can recheck before I open it back up.
Excellent suggestion.