: Guidance on Oil Dye and where the leak is

05-13-10, 05:07 PM
This weekend we need to find where the oil leak is on our 94 racing caddy. Like I have said, it is a leak, not a drip so I think it is the rear main seal.


When I put the die in (car is on a lift) where would the leak be if it was say

* Rear Main Seal
* Oil Pan
* Half seal
* Oil filler
* Any other things that could leak?

We have everything to fix the rear main seal, but nothing for the other stuff. So if you can help guide me on where I should be looking I would appreciate it.

We need to get it fixed this weekend

05-13-10, 09:18 PM
Oil pans and halfcases don't leak like you describe. They seep. Check in the vicinity of the oil filter. The adapter seals (O rings) are there as well as the pressure switch and cooler lines. They generally seep as well.

05-14-10, 10:30 AM
Dye probably won't help if this leak is as bad as you say.....

The rear main seal will drip at the transmission/engine joint - the bottom of the "bell housing".

The front cover seal drips behind the harmonic balancer.

The oil filter adapter will drip.......at the adapter flange.

Is the oil level sensor still installed ??? That could have a crack in the plastic hex head or a bad electrical connector (internal seal).

Is there a washer on the oil drain plug, and is it firmly tightened - not torqued to "squeak tight and a quarter turn" - just tight ?

Oil cooler lines (if any) will drip either at the quick-connect fittings at the front of the filter adapter or at the metal to high pressure line swages; maybe at the radiator tank end fittings.

(Seems that, for all the time and money you've dumped into trying to make a FWD Cadillac into something it will never be, you could have modded almost any RWD car on the planet and been on the track a month ago.......just sayin')

05-14-10, 11:52 AM
Actually we haven't really spent much money, just time.

And dude, it is a racing caddy, that is just sweet.

05-14-10, 07:55 PM
When trying to determine whether mine had the dealer defaulting half-case leak or the oil pan leak, I did this:
1) raise the front-end on ramps
2) spray purple power on the block and trans from the bottom
3) wait 5mins, hose off with garden hose
4) let dry overnight, start engine and run for 3-5mins only
5) check from below with high power flashlight
You'll see any oil seeping/leaking very easily.
Mine was just the oil pan seal, but they did the rear main while they were there, too.