Some strange oil found in the tunnel of the body

PDKLOL · 12-10-2018, 06:18 AM

Hey guys,

Car is an 87 Carrera 3.2 with G50. Stock everything for engine and transmission.

Two things related to oil:

A few days ago I was under the car and noticed some wetness on the underside of the body. It looked like it was leaking out of all of the plastic drain plugs running down the center of the car. I did some inspecting and found a decent amount of what appeared to be engine oil in the tunnel. I pulled all the plugs and let it drain as best I could. It was sloshing around in there and even making it up to the pedal cluster area. The weirdest thing about this is that there are no oil lines in that part of the car or any reason why oil would be in the tunnel. My best guess was that maybe at some point in it's life, some oil made it in there during some previous ownership. Thoughts?

Secondly; I also noticed that my fittings for the oil return lines from the oil cooler up front and in the back by the reservoir have some seepage. Are there o-rings in there that need to be replaced? Suggestions on how to resolve this issue?

Thanks!

The car

The oil at the cluster...I promise you it's not brake fluid and it's not coming from the master cylinder and clutch master.

T77911S · 12-10-2018, 06:37 AM

check oil leaking from tranny shift rod

I was going to suggest checking the vacuum hose to the booster but that's too much oil.

you don't have to worry about rust in the tunnel

PDKLOL · 12-10-2018, 06:40 AM

Quote:

Originally Posted by T77911S

check oil leaking from tranny shift rod

I was going to suggest checking the vacuum hose to the booster but that's too much oil.

you don't have to worry about rust in the tunnel

So what's interesting is that I took the inspection plate off that allows you to adjust the shifter in the back and that's the end of the tunnel. There was absolutely no sign the oil was coming in from there either. I also check that vac line just outside the tunnel under the car and it was bone dry.

I'm perplexed.

GH85Carrera · GH85Carrera's Garage

My only suggestion is to clean it all up as much as is reasonable and wait to see it it comes back. It could well be from something a previous owner spilled.

If in isn't the brake fluid, the only other thing with oil is a fan motor that someone over oiled, or the AC system oil, and only the evaporator on the other side of the firewall could leak much. Is the passenger side dry?

PDKLOL · 12-10-2018, 09:05 AM

Quote:

Originally Posted by GH85Carrera

My only suggestion is to clean it all up as much as is reasonable and wait to see it it comes back. It could well be from something a previous owner spilled.

If in isn't the brake fluid, the only other thing with oil is a fan motor that someone over oiled, or the AC system oil, and only the evaporator on the other side of the firewall could leak much. Is the passenger side dry?

AC system was deleted before I purchased the car so none of those lines are in the car. The oil lines on the pass side of the car are a little damp at the fittings but that's pretty much it for leaks in general on the car.

SalParadise · 12-10-2018, 09:08 AM

Last owner was probably in there and saw the area rusting so he dumped oil down in there to stop it from growing. I've seen this happen.

You'd be surprised how much oil can get through the trans shifting rod through the tunnel and into other places over time. I had at least a quart or two that went in there from 1975 until now - all from the shift seal on the rod as someone else already pointed out.

T77911S · 12-10-2018, 09:10 AM

clean it up as said.

PDKLOL · 12-10-2018, 09:12 AM

Quote:

Originally Posted by SalParadise

Last owner was probably in there and saw the area rusting so he dumped oil down in there to stop it from growing. I've seen this happen.

You'd be surprised how much oil can get through the trans shifting rod through the tunnel and into other places over time. I had at least a quart or two that went in there from 1975 until now - all from the shift seal on the rod as someone else already pointed out.

Very interesting to know! I did not see any signs of rust when inspecting it but I might have missed something when I was in there. I would be surprised if oil had come from the shift seal on the rod because that entire assembly was bone dry. It was just oil at the bottom of the tunnel.

KTL · 12-10-2018, 10:43 AM

If someone spilled brake fluid in the trunk, there's a depression under the brake booster assembly that allows the fluid to leak into the floor area near the pedals. I know this because I once had a major brake fluid spill in my former '87 (pressure bleeder hose cracked open) and I had a lot of cleanup to do...,..... Worth a look in the trunk to see if there's any signs of brake fluid spillage.

You would be able to tell pretty easily if it was gear oil. That was my first reaction upon reading this. But then you said there's no oil at the rear access cover and you'd know by the stink of gear oil.

proporsche · proporsche's Garage

as salparadise...said..i have seen it too..some people put oil in that area to prevent rust..also other places in the 911....clean it and you will be fine..

Ivan

Flat6pac · 12-10-2018, 10:56 AM

Downside on some of the suggestions is a G50 shifter does not extend into the chassis like a 915 extends into the tunnel
Bruce

PDKLOL · 12-10-2018, 10:56 AM

Quote:

Originally Posted by KTL

If someone spilled brake fluid in the trunk, there's a depression under the brake booster assembly that allows the fluid to leak into the floor area near the pedals. I know this because I once had a major brake fluid spill in my former '87 (pressure bleeder hose cracked open) and I had a lot of cleanup to do...,..... Worth a look in the trunk to see if there's any signs of brake fluid spillage.

You would be able to tell pretty easily if it was gear oil. That was my first reaction upon reading this. But then you said there's no oil at the rear access cover and you'd know by the stink of gear oil.

I had everything opened up this weekend and not a drop of brake fluid could be found anywhere in the frunk or near any of the lines or cylinders. It is not smelly and my the viscosity, we are going with engine oil.

Quote:

Originally Posted by proporsche

as salparadise...said..i have seen it too..some people put oil in that area to prevent rust..also other places in the 911....clean it and you will be fine..

Ivan

I am hoping that's all it is. It's also not matching to the oil that would be in the engine in terms of color. It's almost like relatively new engine oil. We cleaned it out as best we could and left the drain holes open for now to get the rest out. I'll plug it back up and report back.

Any suggestions about how to get the oil seepage issue resolved on the oil lines?

proporsche · proporsche's Garage

If the oil lines are a little wet no big deal if seeping put wrench on it.Otherwise it is possible thet the fitting themselves are leaking.
Take a picture and show us..
As Bruce said g50 trany`s rod has no connection to the tunnel so no oil can go inside...

KTL · 12-10-2018, 11:12 AM

Agreed the G50 shift shaft does not poke into the tunnel as far as the 915. But if the rubber boot is in place, the oil could run through the boot and dump into the tunnel.

There's no o-rings or seals on any of the oil lines at the oil cooler up front or at the oil tank in the rear. They're all spherical compression fittings. W/out seeing pictures, I have to assuem the wetness you're seeing is weeping from the rubber hose at the crimp collars.

PDKLOL · 12-10-2018, 11:24 AM

Thanks guys. I spoke with the previous owner and he told me that the transmission did in fact leak and then was rebuilt so that would explain why everything looked so clean and had no signs of leakage. I'm feeling a lot better about this now.

I will grab some photos of the oil lines this afternoon. If it's coming from the crimp collars, I assume the solution would be to replace the lines?

SCadaddle · 12-10-2018, 11:36 AM

This is the reason that my friend that restores these old cars cuts a small hole in the bottom of that boot that fits between the nosecone of the transmission and the body at the tunnel. IF you get a leak from the shifter at the nosecone, you will see it on the ground first and not wind up with an oily tunnel.

PDKLOL · 12-10-2018, 11:45 AM

Quote:

Originally Posted by SCadaddle

This is the reason that my friend that restores these old cars cuts a small hole in the bottom of that boot that fits between the nosecone of the transmission and the body at the tunnel. IF you get a leak from the shifter at the nosecone, you will see it on the ground first and not wind up with an oily tunnel.

It looks like that was done when he had the G50 rebuilt. Smart move on your friends part!

proporsche · proporsche's Garage

that booth hole would only work on 915 trany not on G50....

Ivan

7783911 · 7783911's Garage

PM sent..gotta know what color code that is!!!