Oil Leak ? [Archive] - The Chrysler Minivan Fan Club Forums

: Oil Leak ?

02-05-2008, 09:44 PM
Hi all great forum
My 1990 3.3L automatic developed a bad engine oil leak where I have to now add oil everyday. Its at back area my guess either oil pan or rear seal. Had a so so mechanic bend down look at puddle under car and say seal $400 plus. Could the oil pan leak that much or is it probably the rear seal and being pushed out by pressure or is there also that much pressure in the oil pan?:ask_wsign He took $700 of me last month to fix my other car so now I have to fix this myself. Any tips or ideas would be appreciated.

02-05-2008, 09:59 PM
Does it develope a puddle only when running? If it puddles when off also, you're probably looking at the pan. I'm actually expecting my '90 OEM manual to come in the mail soon, so I'll be more help then.:ask_wsign

02-05-2008, 10:02 PM
I agree with Ghost...If it enlarges when running you may be looking at rear seal...slow leak all the time points more toward the pan..

02-05-2008, 10:04 PM
Oil pan is no problem. 10mm socket is all you should need. Rear seal is something else as the tranny must come out and flex plate removed to change it. You could also have a valve cover leak. How about the PCV system? Is the crankcase under pressure? If so, you could be forcing oil out of the engine. Any oil in the air cleaner? The crankcase should be under a vacuum from the PCV system unless you have a lot of blowby.

Best thing to do is get the engine washed so you can identify just where the oil is leaking. Just my $0.02.


02-05-2008, 10:20 PM
Thks for help,,, on gravel pad just put a piece of wood under to see if it leaks overnight without running it,,, yes going to have to wash it so much oil under there never be able to narrow it down. Will post as I find out more. My other question was is there much pressure in pan for it to force it out or is it mostly pressured up to moving parts. Or maybe too much pressure as was said that may be my problem.

02-05-2008, 10:42 PM
A rear seal leak will be heavier when the oil level is high, or the vehicle is parked at an angle, favourable to the leak. After a liter or more leaks out, the leak may slow down considerably. The engine doesn't necessarily have to be running for the oil to leak out quite quickly down to a certain level.
If you were parking your vehicle on the level, the leak could be minimal. If you then changed your parking space and started parking on an angle, the oil leak may increase or decrease.
Had a Dodge Shadow with 2.5 engine, notorious for rear seal leaks, and the above is based on how it leaked. I thought the oil pan was rusted but a brand new oil pan did not stop the problem.
Is the leak adjacent the transmission (rear seal location). May have to operate the vehicle at the "add oil" mark and monitor it frequently.
If this leak appeared suddenly, then I would bet you changed your parking arrangement at that time.
Other than taking the oil pan off and checking it out, I don't see how one could determine the source of the leak other than if wetness is near the middle of the oil pan, I would tend to rule out front or rear seals.

02-05-2008, 10:45 PM
I dont think there is much pressure on the pan...The pump just forces the oil into the motor..then it runs back down to the pan...There may be some but not much pressure on the pan...

02-05-2008, 10:51 PM
Thanks for info jeep,, thats very interesting. Making me think,, it did sit for a while not being used and probably not very level, maybe seals or gaskets dried up a bit.... Another question which I bet I can guess answer to ,,,, Is it safe or wise to put in the stop leak additive I saw advertised or is that for just a few drops here and there a minor leak?

02-05-2008, 11:04 PM
Thanks. Probably no harm in trying but wonder what that does to an engine. Sometimes seals leak because of scoring or deposits on the shaft. Don't think it would be effective in that case.

02-05-2008, 11:29 PM
Another question which I bet I can guess answer to ,,,, Is it safe or wise to put in the stop leak additive I saw advertised or is that for just a few drops here and there a minor leak?

Well, like you said, you already know the answer. But yeah, it'll gum up in your engine. If it's leaking, it's for a reason, better to fix it than to band-aid it. Just my 2 cents.:beerchug:

02-05-2008, 11:59 PM
Well thank you all.. You have been very very helpful. Will do my homework now and go thru the steps and checks you all suggested and let you know what happens.

Thanks again


02-06-2008, 12:14 AM
"So, for any of you considering oil leaks on your vans, if you change the valve cover gaskets make sure all the crankcase vent holes flow freely. If you get enough pressure it can easily vent out other places, like main seals, etc."

Just saw this in another post, thought it might help.

02-06-2008, 01:02 AM
Another problem is oil leaks. Anytime you bolt aluminum to iron, the gasket in between is compromised, due to the expansion differences between the two metals. This is particularly evident in the chain case module gasket. The gasket moves over time and creates a gap just above the oil pan rail, and boy does it make a mess. Lower intake gaskets leak in the corners. An upgraded gasket was designed with longer, tapered rubber ends that was supposed to end the use of RTV, but RTV will always be a necessity on that application.

This might help also?

02-06-2008, 07:24 AM
Hey Ghostimage. Your van do a 90 degrees????? Must be slippery out in Wiinnipeg. :biggrin:
Oooops, sorry, didn't mean to wake you up. 8:20 am here and 6 inches of snow to shovel. My aching back. :jpshakehe

02-06-2008, 11:38 AM
Hey Ghostimage. Your van do a 90 degrees????? Must be slippery out in Wiinnipeg. :biggrin:
Oooops, sorry, didn't mean to wake you up. 8:20 am here and 6 inches of snow to shovel. My aching back. :jpshakehe

No 90 degrees, but I sat for a few seconds, wheels spinning at idle from a red light. Gotta love having skating rinks for roads. Well, at least theres no snow to shovel :blink: Yet.

02-06-2008, 02:21 PM
Hi guys Used to live in Winnterpeg , now in BC.. winters too brutal..
Anyways,, wash it as good as I could to help see,,, drove it up on ramps approx 6'' so it as at an angle now front up rear on ground... snugged up bolts on pan,,, started it and it does not seem to be leaking as it is sitting,, now I'm not sure if it was the tightening of bolts that did it and oil at angle now? But wouldn't it leak even at angle if it was the seal? Going to back it down and see what happens, but thought I would ask just to get some feedback.

02-06-2008, 03:08 PM
The seal can definitely leak when the vehicle is at an angle, including side to side, depending on whether that angle puts more oil against the seal or takes it away. Was the leak near the transmission (a possible "rear" seal leak)?

02-06-2008, 04:15 PM
Don't guess. It's costly. Clean the engine and trace it down to the source. There are flourescent dies you can put in the oil to help.

02-06-2008, 07:10 PM
Well I snugged up bolts on pan , didn't seem to be very loose, no leaks while up on ramp,,, backed it down off ramp ran it for 10 minutes,, not a drop!!!!
Boy am I glad I didn't rush off buy pan gasket and seal and start stripping it down... Touch wood but it was leaking about a 2" circle in 5 mins,,, not a drop now....
Thanks to all of you for the help... Guess it pays to start at the simple things first and work your way thru...


02-06-2008, 07:19 PM
Forgot to say ,, the know it all mechanic that bent down looked at the puddle under van and said rear seal $450 plus,,, would have done it and gladly taken my hard earned dollars....

02-06-2008, 11:01 PM
Glad to hear everything work out for you. And that your money didn't walk away on ya!

02-06-2008, 11:21 PM
Yes, start with the simple things first. If that doesn't work you might want to take the oil pan off to inspect it and its gaskets. There will be more than one gasket to replace I'm thinking, probably 4 based on past experience with other engines.
Good luck. Keep your fingers crossed.
Cheers :beerchug:

02-06-2008, 11:34 PM
If he even did it!!!! I know a few that woulda tightened the pan bolts, cleaned the sucker up real good and TOLD you he raplaced the rear main seal !!! Gotta be careful who you let peak under your hood now-a-days !!!

02-07-2008, 05:16 PM
Maybe there's no oil left to leak out?! :-)

02-10-2008, 12:42 PM
This type of oil leak (oil pan gasket or oil seal) is dependent on a few simple criteria:
- The oil pan gasket and the oil seals are basically at the same level (distance above a level ground surface) except the oil seal encasement protudes down into the oil pan area somewhat, making the bottom part of the oil seal slightly lower than the pan gasket.
- The oil pan is a container. If the container is full and you tip that container, such as being parked on a side hill, the oil will spill out, or try to, unless the pan gasket and oil seal are tight. If the oil in the pan is only at the "add oil" mark, or some in between level, then the oil may not be able to spill out unless you park on a steeper side hill.
- With the engine operating, pressure against the oil seal or oil pan gasket is minimal as the oil pump is picking up oil from the pan, and pumping it up into the engine where it is dispersed and allowed to run back down into the oil pan. "Crank case ventilation" (you know - those PCV valves) comes ino play which basically vents the chamber where the pan gasket and oil seal are.
- If you park your vehicle on the level or leave the oil at the "add oil" mark and park on a slope, there may be minimal leakage, maybe not even enough to add oil between oil changes.
- If you park on a side hill however, significent oil leakage will likely occur, and especially so if your oil had been topped up to full.

One vehicle we had was considered by me to be a non oil user (did not add oil between changes), although I knew there was some indication of oil leakage, insignificent though it seemed. When my son moved into an appartment and started parking this car on a side hill, oil would leak out profusely until it reached the "add oil" mark, where it tended to stay. Rear oil (engine) seal leakage was the problem and it responded to the level of oil against it in the "parked" position.