Last week some spots of oil showed up on a piece of paper I had placed under the dash on the passengers side. I am pretty certain it is engine oil and nothing else. I assumed it was coming from the oil pressure gauge. There is no sign of earlier leakage there, but I suppose maybe it leaked in the past, and just soaked into the carpet. If so, you cannot see or smell it. This was a very small amount of oil, but still that stuff is supposed to stay inside the engine.

When I pulled the glove box liner yesterday and looked at it, I could see where oil had accumulated in the lip on the back of the dash panel sheet metal, and then dripped through one of the stock holes in it, (most likely the holes drilled for the factory, under dash AC). Yet, I could see no evidence of a leak from the gauge itself. I tightened the fitting on it, but it really did not move perceptibly. The gauge does sit in the dash above the lower edge of the dash stamping, so a leak would accumulate there. The line to it is copper, and runs nearly directly forward into the engine compartment. Oil running down the line would not drip into the dash but onto the heater box.

So two questions:

1. Any ideas what is going on? Has anyone else seen an intermittent leak from a mechanical oil pressure gauge?

2. Should I replace this, or just watch it and see what brews? Does anyone think disaster is possible?

I have left the glove box liner out so I can monitor it for now.

Sam

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Sam,

Clean that copper line & back of gage well with brake cleaner so it is oil free and dry, than run car for a while checking for new oil deposits.

Does the hole through fire wall have a plastic or rubber bushing in place to prevent chaffing copper line on steel sheet metal?

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67' Dart GT Convertible; the old Chrysler Corp.
82' LeBaron Convertible; the new Chrysler Corp
07' 300 C AWD; Now by Fiat, the old new Chrysler LLC

I'll check for the grommet. I would think I would have done that,but what you "know" for sure is what gets you in trouble.

There were no oil deposits on the back of the gauge. That was the "weird" part. Thanks.

Sam

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Get the motor good and warmed up and drive it for awhile fast enough for the oil pressure to be up. When the oil is hot and thin you'll find your leak.

A compression style fitting doesn't have to be very loose to leak a little, you may have already fixed it.

NAPA usually has a boxed assortment of grommets for not too much money. I got a box of grommets, box of O-rings, and a box of vacuum caps for like $9. I haven't used any of them, but they were way too cheap to pass up.

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Official Cookie and Mater Tormentor.

Upon closer inspection I can see that this oil leak has been going on for awhile. The carpet is noticeably darker there under the dash. There is no way of telling how long it has been happening. There are so many holes in the firewall that I just thought the light oil smell was from the engine bay.

Dennis, I hope you are right in your thinking the leak may be fixed already. The odd thing about this gauge is that there is not a nut to tighten against with the fitting. You must hold the gauge in one hand and turn the compression with the fitting wrench in the other. It makes it hard to really crank down on it hard. I think I will replace it.

Sam

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Sam, do yourself a favor and spend the money for some Earl's fittings and a braided steel line. You'll be glad you did.

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Official Cookie and Mater Tormentor.

OK, I will do that. Will the Earl's fittings hook up to the rear of this oil pressure gauge? Are they standard sizes? While I am asking for advice, do you have a gauge to recommend? This gauge is Autogage, and maybe 10 years old. It is looking pretty tattered by now, and is suspect in other ways as well now.

Sam

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Dennis, I looked them up on line with several suppliers and could not tell how you would interchange the AN fittings with the compression fittings that are on there now. I might have to travel up to Frederick and talk to the counter guys at Maryland Performance to get the stuff needed to make this work.

I certainly do not mind spending the money. It is the knowledge I lack at this point. Do you believe I first hooked this up with nylon hose? That leaked right away. The copper is an upgrade from there.

Sam

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I always run Autometer gauges. Autogage is the "economy" version of those.

Yes, going in person is the best way to do it. With the differences in the fittings on the back of the gauge, it's best to have everything in your hands.

I am lucky enough to have a really good speed shop close to me that will actually beat Summit/Jag's prices.

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Official Cookie and Mater Tormentor.

You are lucky Dennis. They are becoming an endangered species around here. The only good one is about a 45 minute drive. And, the owner of that one is a little difficult to deal with. He gives me the impression that if I don't have at least $2000 to spend, I am wasting his time, which is never. I also felt really looked down upon for having a slant six, and a Mopar. I don't think that was just my perception.

He used to be right around the corner. I did not realize how much I would miss the knuckle head when he moved.

Sam

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Hey Sam, I am still running the plastic line on mine, i did cover it end to end with rubber hose, so that if it does leak, it will run down back to the engine... just another thought... enjoy.

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65 Coronet, 4 bbl, .060 over, mild cam.
66 Valiant, Black, 3spd, Hyperpak, headers.
works in progress...

I went out and bought a new oil pressure gauge and braided line last week, and installed them tonight. I hadto get through Christmas before I could think about this. Upon examination, I could not see any obvious leak at either end of the old copper line, but I think both ends had some sort of minor, slow drip sort of leak. The fitting at the engine block end was wet with oil, as was the side of the block just a bit. I always wipe all this down after oil changes, and I have the tall valve cover wing nuts which I tighten regularly. So, I do not think the oil filter or the valve cover were the culprits there. And while I could not see any obvious leak at the gauge end, this is the only place oil could come from under the dash. My conclusion is that the compression fittings on the copper tubing eventually gets distorted a little and cannot be a positive, leak proof fit at that point.

I fired it up and checked for leaks, and all seems OK. But then it looked OK with the old copper line.

The braided line was $60 and the gauge was about the same. The only thing that bugged me was they did not have a gauge in black, so I put a silver faced one in,which does not match. I was too impatient to wait. OH well. I guess I will get used to it. Thanks for the advice to go this route. I will let you know how well it works.

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