View Full Version : Help - I'm Stranded by an Elusive Oil Leak!

10-27-2004, 11:26 PM
Yesterday, I had to drive some 360 miles to a family funeral. Half of this was on two lane road and half on an interstate highway. This afternoon, while preparing to leave for my return, I started the motor and saw the oil light flicker. It had never done this before, so I checked the oil levelfound it surprisingly low. I added two quarts of oil. Peering underneath the car, I saw no substantial leak.

On the drive north and east from Massachusetts to Maine, I drove for a couple of hours and stopped for a break. When I slowed up I noticed the light flicker slightly again. I turned off the car and found the oil level down once again. By now it's quite dark so I can't view much under the car. I had to stop twice again over the next 120 miles to check the oil and found it low again.

The car was running quite well; the power was spot on and the temp gauge stayed at the normal 1/4 - 1/2 level.

When I arrived a motel tonight, I noticed fresh oil underneath the point where the transmission bolts onto the engine, and near where the oil pressure switch is located. The oil appears to be away from the filter housing.

The back of the car, under the trunk lid, has a spray of oil on it from the drive. This leads me to believe that the oil is pushing out under pressure.

I have another 150 miles to go tomorrow to return to work. Any ideas of what to look for under the car?


Jeff Aronson

10-27-2004, 11:46 PM
From going back to your old posts, I believe you are talking about your TR7?
If so, your delema sounds very familliar to what I went through last summer.
You say you see some around the oil pressure switch? I was loosing oil, couldn't find any leak, until I started up the car, crawled under, and saw a fine spray shoosting out the end of the Oil Pressure Switch, where the prongs are. It was very fine, but under pressure was really comming out.
Hope that may help.

10-28-2004, 01:26 AM
This is one of those cases where it's nice to have access to a lift or oil pit. Take it to a local oil change place or corner mechanic, and see if you can get under it while it's running. While I suppose you can jack it and throw it on jack stands, it would be so much easier and safer to get it on a lift. My guess is that Paul's got your answer, otherwise your rear main seal is way-past toasted, but I think you'd have other symptoms.

10-28-2004, 07:42 AM
I'll check the rear main seal and the pressure switch area while the car is running. The leak doesn't seem to be affected by engine speed; the amount of the loss became the same whether I was traveling at 70 mph or 50 mph.

Thanks - I'll post the likely answer.


10-28-2004, 10:12 AM
Yes, it's my '80 TR-7 Spider that's become the Exxon Valdez.

When the sun rose this morning, I put on the "monkey suit" I always carry in the trunk of the TR-7 and checked out the car. When I pulled off the connector at the oil pressure switch, I found that it was leaking around the plastic plug at the three pronged connector. You could see if pulse out a shot of oil with every stroke of the oil pump.

Fortunately, a local auto parts store had the '80 TR-7 listed and had a compatible part. I had to buy a special socket too to in order to get the old one off the car. The new one is only single prong and is shorter in length, but it fits tightly. There's no leak around the oil pressure switch.

I wanted to have a working idiot light so I picked one female slot for the single prong. At first, I heard something go "click" with the key off. No good. Then I tried another one and found the oil light lit wit the key on, and found it shut off when the engine started. So it's likely to be working at whatever pressure.

I'm going to take it for a test drive before heading out on the final 150 miles of the trip. If there's no loss of oil, then I'll order the right unit from Moss or Vic Brit and then carry this one as a spare.

Thanks for everyone's help. I'm pretty certain this is it.

Jeff Aronson

10-29-2004, 12:42 AM
You mean.... I Might have actually given some information that was helpful to another LBC owner? /ubbthreads/images/graemlins/cheers.gif
Now I really feel like I am getting into the swing of things. So, I guess, the more things that go wrong with my cars, the more I can help!!!!
Gotta love it. /ubbthreads/images/graemlins/thumbsup.gif
Hope the next 150 miles home are problem free.

Paul /ubbthreads/images/graemlins/canpatriot.GIF

Mickey Richaud
10-29-2004, 08:53 AM
You mean.... I Might have actually given some information that was helpful to another LBC owner? /ubbthreads/images/graemlins/cheers.gif
Paul /ubbthreads/images/graemlins/canpatriot.GIF

[/ QUOTE ]

Hey Paul -

Now you can live by one of my personal mottos:

"Once in a while, even a blind squirrel gets a nut!" /ubbthreads/images/graemlins/jester.gif


10-29-2004, 08:02 PM
Just a note to confirm that the problem was the oil pressure sendng unit. It leaked so badly that as I ran the car in the motel parking lot, you could see it push out a squirt of oil with every pulse of the oil pump.

A local Carquest had a "universal" oil pressure sending unit that screwed right into the engine, once I bought the specially sized socket for my ratchet. The total cost was $8 for the unit and $7 for the socket. The "universal" part was a misnomer; the connector had only one prong for a three-prong connector. However, I found the one slot that enabled the pressure switch to function so I'll be ok until I can order the right one from Moss or Vic Brit.

Thanks for all your help.

Jeff Aronson