So my 1991 with 119K miles was leaking oil from the oil pressure sending unit and the cam seals (I have already replaced the spool valve gaskets). The common place the oil sending unit leaks from is the lower seam where the top and bottom metal pieces are crimped together (there is also an O-ring that seals it to it's mount that can leak and you should replace it if you remove the unit). So I cleaned the seam and surrounding surfaces (bottom only) and coated them with JB-Weld. No more leak and the unit works now as it should (it was very irregular before the fix). For the cam seals I put a #18 O-ring (Home Depot - $2 box of 10) around them. I gently pried the outside edge of the seal away from the engine with a screwdriver and pushed the O-ring over and around it. No more leak! I can't say now how long these fixes will last, but they seem fairly adequate. I will report back after 100 or so miles. Considering the costs of a new sending unit (about $240) and the labor saved from replacing the cam seals, I thought it was worth a try. Wish me luck and Happy Motoring!
Fix For Leaky Oil Presuure Sending Unit and Cam Seals
- Thread starter pgilliam1
- Start date
The o-ring idea is pretty cool, not to discount the other fix. The oil is not pressurized against that seal, it is really gravity that has the oil leaking. You will probably be reporting back for a few years
.
Regards,
LarryB
. Regards,
LarryB
The o-ring idea is pretty cool, not to discount the other fix. The oil is not pressurized against that seal, it is really gravity that has the oil leaking. You will probably be reporting back for a few years
Regards,
LarryB
I checked the sending unit for other leak points and didn't find any so I assumed it leaked where the oil accumulated on the seal. Anyway, it works for now and I'll let you know if/when the leaks return. Happy Motoring!
Interesting..I think my sending unit is leaking as well. I may try that.
I actually meant the cam seals, there is ofull oil pressure against the pressure sender
.Regards,
LarryB
I actually meant the cam seals, there is ofull oil pressure against the pressure sender
Regards,
LarryB
Well then, I may be onto something. The O-ring seats fairly tightly so gravity should have little effect and the JB-Weld dries like iron. I'll keep my fingers crossed. Happy Motoring!
The JB weld on the sender has been tried before here on Prime. A search will bring it up - it only lasted a few months unfortunately.
I like the o-ring idea on the cam seals!
Dave
I like the o-ring idea on the cam seals!
Dave
I'd like to try your pressure sender fix as well but there seem to be other posts which suggest it's nearly impossible to get to without mangling the electrical connector. After pouring over the shop manual, I believe the sender is attached to an adapter plate which is below the spool valve assembly on the driver's side of the front cylinder bank. In other posts, I gather that unbolting the coolant reservoir and moving it out of the way may help .. and that removing the adapter plate first before the pressure sender might also help. I'm assuming that I don't have to touch the spool valve assembly? Any other tips you might offer?
Tks ...Ian
Tks ...Ian
It definitiely helps to unbolt and move the coolant tank over (no need to remove it).
You don't need to remove the spool valves either - it just makes it a little more difficult. If the spool valve gaskets are due to be replaced, now's a good time to do them and will allow easy access to the sender.
The sender is attached to the front head, via an adapter block that allows the sender to sit perpendicular to the head. There's no need to remove the adapter block. Keep in mind that there's an o-ring for the head/adapter block, and then another o-ring for the adapter block/sender. Just be prepared for whichever one you decide to remove. Honda part numbers for the o-rings are in this thread:
http://www.nsxprime.com/forums/showthread.php?t=78153
Dave
You don't need to remove the spool valves either - it just makes it a little more difficult. If the spool valve gaskets are due to be replaced, now's a good time to do them and will allow easy access to the sender.
The sender is attached to the front head, via an adapter block that allows the sender to sit perpendicular to the head. There's no need to remove the adapter block. Keep in mind that there's an o-ring for the head/adapter block, and then another o-ring for the adapter block/sender. Just be prepared for whichever one you decide to remove. Honda part numbers for the o-rings are in this thread:
http://www.nsxprime.com/forums/showthread.php?t=78153
Dave
As MacAttack said, there's no need to remove anything except the sending unit. I unbolted the coolant reservior and moved it forward out of the way. Then I took one bolt out that held the wiring harness mounting and I moved it all forward. That gives you good access to the sending unit. Unplug the single connector and remove the unit with a 22mm open end wrench. The wire on the end of the unit does a lot of twisting so try and turn it with the unit as it comes off/on. Before you apply the JB-Weld make sure you prep the bottom surface and seam. I wire brushed the seam and cleaned it with fast drying laquer thinner to remove any residue. If mine starts leaking again I'll be sure to post it. Happy Motoring!
I woud like to see a picture of the cam seals with the o-ring placed behind it. That is of course, if you can actually see them after they are installed. I think mine are starting to weep and I would love to give this option a try. Home Depot here I come!! :biggrin:
Congrats on trying to save some $$$ in these tough times!!
Congrats on trying to save some $$$ in these tough times!!
Per your request, photos attached:
Attachments
Awesome!!! Thank you.
Tks to both pgilliam1 and MacAttack for the add'l comments.
- Joined
- 26 May 2010
- Messages
- 21
bringing back an old thread....
pgilliam1 - any updates on the o-rings on the cam seal? has it held up after a few years? Thanks
pgilliam1 - any updates on the o-rings on the cam seal? has it held up after a few years? Thanks
The o-rings held for awhile but started oozing just a bit after a couple of months. I put some Hondabond on my fingertip and ran it around the outside of the o-ring and that has stopped it completely (going on 3 months with no leaks). Maybe coating the o-ring with Hondabond before installing it would be a good idea.
The JB-Weld also failed after a couple of months and the sending unit went back to causing erratic oil pressure readings. I installed the SOS replacement and relocation kit and all is well. I recommend SOS's kit because I have read here that even new OEM sending units have failed within short intervals after installation and their costs are rediculous comparitively speaking to the SOS unit.
The JB-Weld also failed after a couple of months and the sending unit went back to causing erratic oil pressure readings. I installed the SOS replacement and relocation kit and all is well. I recommend SOS's kit because I have read here that even new OEM sending units have failed within short intervals after installation and their costs are rediculous comparitively speaking to the SOS unit.
I tried to perform this little trick, but was unsuccessful in getting the o-ring in. There just wasn't enough room. I replaced the cam plugs with SOS aluminum ones when I did the tb/wp. They were leaking a lot more than I realized. I'm glad that job is behind me for another 7 years.
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