1st Generation Specific (1979-1985) 1979-1985 Discussion including performance modifications and technical support sections

Oil leak. Most likely cause!

Thread Tools
 
Search this Thread
 
Old Oct 18, 2023 | 06:49 PM
  #1  
Slow_sevens's Avatar
Thread Starter
Senior Member
 
Joined: May 2021
Posts: 699
Likes: 292
From: California
Oil leak. Most likely cause!

Leaking drivers side rear of motor. Below oil filter. Slow leak, been ignoring it but since I have car up in the air replacing manifold thought I would tackle this one too. Have replaced the oil pedestal O rings but leak continues. To orientate photo from below, brass colored cylinder to right bottom is the starter motor.

pic from underneath.





photo from above.



Reply
Old Oct 18, 2023 | 07:02 PM
  #2  
j_tso's Avatar
Rotary Freak
Tenured Member: 20 Years
Liked
Loved
Community Favorite
iTrader: (2)
 
Joined: Dec 2004
Posts: 1,973
Likes: 400
From: Austin, TX
oil filter pedestal o-rings or the pressure sender are the most likely culprits in that area.
Reply
Old Oct 18, 2023 | 07:07 PM
  #3  
Slow_sevens's Avatar
Thread Starter
Senior Member
 
Joined: May 2021
Posts: 699
Likes: 292
From: California
Originally Posted by j_tso
oil filter pedestal o-rings or the pressure sender are the most likely culprits in that area.
Oil filter pedestal o-rings done. For the pressure sensor Is it a case of replacing the sensor, or an o-ring or seal between sensor and motor?
Reply
Old Oct 18, 2023 | 08:12 PM
  #4  
j_tso's Avatar
Rotary Freak
Tenured Member: 20 Years
Liked
Loved
Community Favorite
iTrader: (2)
 
Joined: Dec 2004
Posts: 1,973
Likes: 400
From: Austin, TX
The sensor has a tapered thread. Try reinstalling it with thread sealant or teflon tape.
Reply
Old Oct 18, 2023 | 08:35 PM
  #5  
Slow_sevens's Avatar
Thread Starter
Senior Member
 
Joined: May 2021
Posts: 699
Likes: 292
From: California
Originally Posted by j_tso
The sensor has a tapered thread. Try reinstalling it with thread sealant or teflon tape.
Excellent! Will give that a try. Much appreciated.
Reply
Old Oct 19, 2023 | 01:20 PM
  #6  
Frogman's Avatar
Senior Newbie Member
 
Joined: Jun 2017
Posts: 1,051
Likes: 89
From: Downey California
Originally Posted by Slow_sevens
Excellent! Will give that a try. Much appreciated.
You need to inspect your coolant line that's drenched . If it shows any sign of damage or deterioration please change it . If it's just dirty clean it as if your infant child had to lick it.
Oil will literally eat through that line and causes a massive coolant leak = bye bye engine .
Reply
Old Oct 19, 2023 | 01:47 PM
  #7  
Slow_sevens's Avatar
Thread Starter
Senior Member
 
Joined: May 2021
Posts: 699
Likes: 292
From: California
Originally Posted by Frogman
You need to inspect your coolant line that's drenched . If it shows any sign of damage or deterioration please change it . If it's just dirty clean it as if your infant child had to lick it.
Oil will literally eat through that line and causes a massive coolant leak = bye bye engine .
Ha! I will go ahead and replace that line. I rebuilt the engine last year and it’s been running GREAT so certainly want to take care of it. Appreciate the tip.
Reply
Old Oct 19, 2023 | 02:44 PM
  #8  
Slow_sevens's Avatar
Thread Starter
Senior Member
 
Joined: May 2021
Posts: 699
Likes: 292
From: California
Well crap. Looks like previous owner helicoiled the sensor in. Threads are pretty much gone on sensor, and there was a spring like item wrapped around the threaded section of the sensor.

So…..

Option 1. Buy a new sensor and chase the female thread in the iron with a tap.

Option 2. Reinstall using the existing helicoiled setup with high temp thread seal?

If option 1 anyone know the specs for the thread on the oil pressure sensor? I may be able to measure it off the existing sensor, but threads are pretty gone.







Last edited by Slow_sevens; Oct 19, 2023 at 02:47 PM.
Reply
Old Oct 19, 2023 | 02:53 PM
  #9  
1badFB's Avatar
GSSL-SE
Tenured Member: 20 Years
Liked
Loved
Community Favorite
iTrader: (1)
 
Joined: Aug 2003
Posts: 1,386
Likes: 240
From: Canada
1/8 BSPT

I'd be reluctant to tap it (in place) unless you're confident you can extract all the chips.

I'm a hack but if it didn't seal with some fuel safe teflon tape, I'd JB weld it in haha.

Reply
Old Oct 19, 2023 | 03:24 PM
  #10  
TreeFittySeven's Avatar
Rotary Enthusiast
Tenured Member: 10 Years
Liked
Loved
Community Favorite
 
Joined: Jun 2013
Posts: 840
Likes: 2,410
From: Mom’s basement
So, you have confirmed the iron is stripped as well?

would think the sensor would strip way before the iron. If I the iron looks 1/2 way decent, I would just putt a temp plug in, chase it a little, vacuum the hole, remove plug and put in new sensor.

JB weld sounds like a good idea if the iron is screwed to where it needs drilled etc.
Reply
Old Oct 19, 2023 | 03:40 PM
  #11  
Slow_sevens's Avatar
Thread Starter
Senior Member
 
Joined: May 2021
Posts: 699
Likes: 292
From: California
Originally Posted by ATC529R
So, you have confirmed the iron is stripped as well?

would think the sensor would strip way before the iron. If I the iron looks 1/2 way decent, I would just putt a temp plug in, chase it a little, vacuum the hole, remove plug and put in new sensor.

JB weld sounds like a good idea if the iron is screwed to where it needs drilled etc.
Was thinking the same thing. Screw in a fitting with the same thread just to tidy things up before threading in the sensor. Got a new one coming from Mazdatrix. Will let you know how it goes.
Reply
Old Oct 20, 2023 | 10:07 AM
  #12  
Banzai's Avatar
Happy Rotoring!
Tenured Member: 15 Years
Liked
Loved
Community Favorite
iTrader: (15)
 
Joined: Dec 2007
Posts: 2,622
Likes: 569
From: Iowa
So have you confirmed if the threads in the iron are intact or not? Hard to tell from the pic, but that "spring like" item may be the actual helicoil. You did say the iron had been helicoiled. I've saw plenty of bolts and fasteners come out with the threads of the hole it was installed in, just like that. However, in this case I would say it is not from the base material.

Cast Iron is soft, when it strips it would crumble and just break up, not come out as a string of material. Helicoils are stainless and will come out like that. Of course, if thats the case, the threads in the cast iron would now be toast.

In that case, even another helical would not repair it since there would not be any remaining material to tap into. The next step insert-wise, would be a premier style insert. These are larger, almost like a bushing instead of wire type helicoils. You drill and tap the base material for the OD thread on the insert. Once installed, these inserts are "staked" in place by driving in two integral stakes on the inserts OD thread, to prevent it from turning. The ID will have the original thread size and pitch. Again, its hard to drill and tap while getting all the debris from getting inside.
Reply
Old Oct 20, 2023 | 10:56 AM
  #13  
Slow_sevens's Avatar
Thread Starter
Senior Member
 
Joined: May 2021
Posts: 699
Likes: 292
From: California
Originally Posted by Banzai
So have you confirmed if the threads in the iron are intact or not? Hard to tell from the pic, but that "spring like" item may be the actual helicoil. You did say the iron had been helicoiled. I've saw plenty of bolts and fasteners come out with the threads of the hole it was installed in, just like that. However, in this case I would say it is not from the base material.

Cast Iron is soft, when it strips it would crumble and just break up, not come out as a string of material. Helicoils are stainless and will come out like that. Of course, if thats the case, the threads in the cast iron would now be toast.

In that case, even another helical would not repair it since there would not be any remaining material to tap into. The next step insert-wise, would be a premier style insert. These are larger, almost like a bushing instead of wire type helicoils. You drill and tap the base material for the OD thread on the insert. Once installed, these inserts are "staked" in place by driving in two integral stakes on the inserts OD thread, to prevent it from turning. The ID will have the original thread size and pitch. Again, it’shard to drill and tap while getting all the debris from getting inside.
I had a close look at the spring like object. Does appear to be a manufactured object, rather than thread stripped away from sensor or iron. It’s flat in section, consistent across its entire length, too clean and perfect to be something that broke away from something else.

And to pick your knowledge further. When you say ‘ If that’s the case the threads in the iron would be toast’ do you mean toast if the spring like object was the threads torn out of the iron, or toast because the simple use of a helicoil would have damaged the female threads beyond useability.

Given motor is in car going to abandon any thread chasing or drilling ideas, and if the female threads are shot resort to epoxy.

Last edited by Slow_sevens; Oct 21, 2023 at 07:17 AM.
Reply
Old Oct 21, 2023 | 12:16 AM
  #14  
Banzai's Avatar
Happy Rotoring!
Tenured Member: 15 Years
Liked
Loved
Community Favorite
iTrader: (15)
 
Joined: Dec 2007
Posts: 2,622
Likes: 569
From: Iowa
I'm saying that if the spring like material is the actual heilcoil insert that pulled out of the iron, it took the female threads in the cast iron with it. I suppose its possible that when removing the sensor, it unscrewed the helicoil from the iron along with the sensor. In that case, there would still be sufficient threads in the iron to re insert another helical. I would put the sensor back in the hole and see if there is excessive play between the hole and the sensor. Do you have the helicoil tap or another insert with the installation tool?
Reply
Old Oct 21, 2023 | 07:16 AM
  #15  
Slow_sevens's Avatar
Thread Starter
Senior Member
 
Joined: May 2021
Posts: 699
Likes: 292
From: California
Luckily the helicoil unthreaded with the sensor. It stayed wrapped around the female thread as I removed the sensor. Installed a new sensor yesterday without the helicoil. Was a little reluctant to start, but once threads engaged threaded in just fine. No play at all. Before I installed I used some skinny plastic tube duct taped to the shop vac to suck any debris out of the hole, and for install used high temp thread sealant. Letting it sit for 24 hrs to cure and will test later today.

And by the way, letting the car sit for 24 hrs when I have got a new RB header and exhaust installed that I have not yet driven is quite the challenge!

Last edited by Slow_sevens; Oct 21, 2023 at 07:19 AM.
Reply
Old Oct 21, 2023 | 11:10 AM
  #16  
KansasCityREPU's Avatar
Out In the Barn
Tenured Member: 20 Years
Liked
Loved
Community Favorite
iTrader: (9)
 
Joined: Mar 2005
Posts: 6,705
Likes: 1,250
From: KC
If you do install a new helicoil, the tang will be an issue. Check out time-serts. https://www.timesert.com/
Reply
Old Oct 21, 2023 | 12:08 PM
  #17  
Slow_sevens's Avatar
Thread Starter
Senior Member
 
Joined: May 2021
Posts: 699
Likes: 292
From: California
Originally Posted by KansasCityREPU
If you do install a new helicoil, the tang will be an issue. Check out time-serts. https://www.timesert.com/
I have a box of assorted helicoils somewhere. Used to run a bicycle shop, and helicoils were used to reinstall pedals if they backed out and stripped the cranks. That was before lawyers got involved and the industry moved to the less risky replacing of entire crank.

But…

So far no need. Just took a test drive with new sensor and no leak.

And…

The Racing Beat exhaust is an absolute joy! I can climb the highway hill to my town at 70 mph in 5th where previously I would need to drop a gear. And the little twisty road near me was a blast. With this little boost in hp and the previously installed McTheory rack and pinion I feel I have me a proper car!
Reply
Old Oct 26, 2023 | 10:31 AM
  #18  
Toruki's Avatar
Rotary Enthusiast
Tenured Member: 15 Years
Liked
Loved
Community Favorite
 
Joined: Oct 2010
Posts: 1,321
Likes: 371
From: MA USA
Originally Posted by Slow_sevens
The Racing Beat exhaust is an absolute joy! I can climb the highway hill to my town at 70 mph in 5th where previously I would need to drop a gear. And the little twisty road near me was a blast. With this little boost in hp and the previously installed McTheory rack and pinion I feel I have me a proper car!
Glad you got your leak repaired, you always post the results of your work and I appreciate that. I recall you had a heck of a time with the CA inspection. Will the current setup pass? I ask because I always thought the RB setup "undoes" all of the emissions stuff.
Reply
Old Oct 26, 2023 | 10:42 AM
  #19  
Slow_sevens's Avatar
Thread Starter
Senior Member
 
Joined: May 2021
Posts: 699
Likes: 292
From: California
It does seem common here that folks disappear after a few rounds of advice. My wife calls me Mr Brightside… So assume they fixed the problem and simply didn’t report back. Most likely something else grabbed their attention and the car goes on the back burner.

On the CA omissions, the real reason for the RB exhaust was to preserve the new cats that got me through smog but were darned expensive. The idea being to not put any miles on a setup that I knew passed smog, but instead stash the cats, air pump and valve, and reinstall for smog next time it is due. But I gotta admit, the extra power is nice!
Reply
Old Oct 26, 2023 | 10:52 AM
  #20  
Frogman's Avatar
Senior Newbie Member
 
Joined: Jun 2017
Posts: 1,051
Likes: 89
From: Downey California
Originally Posted by Slow_sevens
It does seem common here that folks disappear after a few rounds of advice. My wife calls me Mr Brightside… So assume they fixed the problem and simply didn’t report back. Most likely something else grabbed their attention and the car goes on the back burner.

On the CA omissions, the real reason for the RB exhaust was to preserve the new cats that got me through smog but were darned expensive. The idea being to not put any miles on a setup that I knew passed smog, but instead stash the cats, air pump and valve, and reinstall for smog next time it is due. But I gotta admit, the extra power is nice!
The emissions system robs your car of ten horsepower . In japan the 79 had 110 HP , Our California cars had 100 hp with it's smog system .
Reply
Old Oct 26, 2023 | 11:07 AM
  #21  
Slow_sevens's Avatar
Thread Starter
Senior Member
 
Joined: May 2021
Posts: 699
Likes: 292
From: California
Originally Posted by Frogman
The emissions system robs your car of ten horsepower . In japan the 79 had 110 HP , Our California cars had 100 hp with its smog system .
Has anyone put a 12a RB manifold/exhaust swap with everything else OEM stock on a dyno? Seems a common swap. RB claims 22% increase in power at 7000rpm, but would be cool to see if anyone has verified that.
Reply
Old Oct 26, 2023 | 11:19 AM
  #22  
Frogman's Avatar
Senior Newbie Member
 
Joined: Jun 2017
Posts: 1,051
Likes: 89
From: Downey California
Originally Posted by Slow_sevens
Has anyone put a 12a RB manifold/exhaust swap with everything else OEM stock on a dyno? Seems a common swap. RB claims 22% increase in power at 7000rpm, but would be cool to see if anyone has verified that.
My car is mostly stock , My nikki is modified ( Larger jets , mechanical secondaries , no emissions "

RB exhaust did increase my upper end horsepower
significantly
Reply
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
rx7???rx7#1
3rd Generation Specific (1993-2002)
2
May 8, 2004 02:04 PM
overrev
3rd Generation Specific (1993-2002)
4
Dec 15, 2003 11:44 PM
mrb63083
2nd Generation Specific (1986-1992)
5
Nov 5, 2003 04:10 PM
93'roadwarrior
3rd Generation Specific (1993-2002)
1
Oct 1, 2003 01:41 PM




All times are GMT -5. The time now is 10:50 PM.