Oil Leak - Ideas? January 09, 2018, 09:06:29 PM Have an 84 bird, 3.8L, 73K miles. Has developed a significant oil leak. Trouble is eveything is so wet, its hard to tell what is causing mostly. I have done the valve covers, 3x since over 15k miles, both with the rubber gasket, then back to felpro cork. Its not the valve covers. The bell housing, the oil pain, the front cover, all is soaked, but the drips come off the right side of block area, after running down around the starter mounting area and off the edge of cover that seals off the converter area (by the starter). Crossover is getting some drips on it and smoking a bit (hard to tell from all the caked on cooked oil on it). The right side of the block is dirty, but I dont see any significant leak from there in the region that I can see. Itll drip maybe 4-5 drips per minute just idling, more if revved.Any ideas? Im getting close to saying bye to this car, but this is a spare mess around car, but this oil dripping is just too messy to continue.Thanks for the tips.Russ Quote Selected
Oil Leak - Ideas? Reply #1 – January 09, 2018, 10:35:32 PM The only way you can be sure is to clean it up. I would spend a couple bucks on some degreaser (or even brake cleaner) and clean up the suspected area. Then start it up and see if you can see where it's coming from. Quote Selected
Oil Leak - Ideas? Reply #2 – January 10, 2018, 06:45:14 AM I wouldn't be surprised if you found the intake leaking at the rear end seal. I've see some older 3.8L cars (of all types) leaking from the rear of the intake, in a couple of cases I attributed it to increased backpressure caused by cats becoming obstructed. Be ready for this rabbit hole to go deep. Quote Selected
Oil Leak - Ideas? Reply #3 – January 10, 2018, 08:46:50 AM Quote from: TheFoeYouKnow;464217I wouldn't be surprised if you found the intake leaking at the rear end seal. I've see some older 3.8L cars (of all types) leaking from the rear of the intake, in a couple of cases I attributed it to increased backpressure caused by cats becoming obstructed. Be ready for this rabbit hole to go deep.Interesting thought on the cats. The rear intake seal is seeping a bit as Ive looked back there but it doesnt appear to be losing much as its not all that wer back there. So is this a pretty well know effect of plugged cats (causing oil leaks all over)?? Quote Selected
Oil Leak - Ideas? Reply #4 – January 10, 2018, 08:53:38 AM Those older cats are pellet-bed style, they failed all the time. The problem with "plugged cats" as most people think of them, is that people only think about obstructed catalysts in their terminal phase where they don't flow at all. It doesn't happen all at once, and up until they completely block, the pressure has to go somewhere. In a lot of cases, pressure backs up until it becomes excessive blow-by. So then the excess pressure is in the crank case, the PCV can't vent it all into the intake, so it finds its way out and once the seals or gaskets are compromised, oil comes out, too. Not saying this is your problem, but keep it in mind. Even if it is the root cause, you'll still need to find and repair the leak. Quote Selected
Oil Leak - Ideas? Reply #5 – January 10, 2018, 09:27:20 AM Thanks. One thing I should add, is that I use only mobil 1 synthetic in motors, and Im suspect that I helped leaks along by doing this. Ive had 2 of these motors back in the old days, and both motors wore out at low miles (80K ish). They all were leakers, but none this bad. Quote Selected
Oil Leak - Ideas? Reply #6 – January 10, 2018, 11:46:16 AM Quote from: TheFoeYouKnow;464219Those older cats are pellet-bed style, they failed all the time. The problem with "plugged cats" as most people think of them, is that people only think about obstructed catalysts in their terminal phase where they don't flow at all. It doesn't happen all at once, and up until they completely block, the pressure has to go somewhere. In a lot of cases, pressure backs up until it becomes excessive blow-by. So then the excess pressure is in the crank case, the PCV can't vent it all into the intake, so it finds its way out and once the seals or gaskets are compromised, oil comes out, too. Not saying this is your problem, but keep it in mind. Even if it is the root cause, you'll still need to find and repair the leak.And I'll say if blow by was so bad as to push oil out of crankcase, the engine would be sorely lacking in power... Engines will usually fill intake/air cleaner with oil long before they actually leak... I've seen cats plugged so badly that engine would start and die, were not losing oil... Most gaskets before mid '90s were junk, leaked at 10 years, at 30+ they are all but useless... The '86 HO 5.0 I originally used in my Bird was streaming oil out back of intake, extremely common in those engines... At less than 120K mi My '93 Lighting was g oil between block and oil pan, at 191K my '96 F150 5.0 is yet to drip... I dunno how much of improvement is gasket vs the oil pan rail supports, suspect the supports are a major factor...Mobil 1 has seal conditioners I doubt it actually caused the leak...If it's main bearing seals leaking a high mileage oil may help, but I've never seen any improvement on front cover, oil pan etc gaskets... Quote Selected
Oil Leak - Ideas? Reply #8 – January 11, 2018, 08:27:00 AM Is it easier to pull engine or engine and trans together?? Quote Selected
Oil Leak - Ideas? Reply #9 – January 11, 2018, 08:54:49 AM That depends on you, your equipment, and if you can get a helper. Personally, I've never taken an engine and trans together unless I needed them both out, and even then, I've preferred a drop to a pull. That's only because I have facilities and equipment to do a drop. I've got pics of a Fox drop on here somewhere.Speaking of engine pulls, here's what I'm doing today Quote Selected
Oil Leak - Ideas? Reply #10 – January 11, 2018, 09:51:24 AM Ughh, ffin 4.6/5.4, glad I'm retired, don't have to mess with such tripe... I paid a friend to replace the POS plastic intake on my '98 Grand Marquis that busted at 63K mi, didn't want to do it myself(I'd already had intake for a couple months)... When I installed the 5.0 AOD into Bird I did it as a unit, without help, using cherry picker... Definitely touchy... When I pulled it back out I dropped transmission, apparently the old saying "balls shrink with age" applies... Quote Selected
Oil Leak - Ideas? Reply #11 – January 11, 2018, 09:58:16 AM That's a 4.2 with a manual. Just about as bad. Quote Selected
Oil Leak - Ideas? Reply #12 – January 11, 2018, 10:05:04 AM Quote from: TheFoeYouKnow;464227That's a 4.2 with a manual. Just about as bad.Oh yeah, my bad, should have taken a better look... Everything is buried but if nothing else, the three runner exhaust manifold gives it away... Quote Selected
Oil Leak - Ideas? Reply #13 – January 11, 2018, 12:23:56 PM The hard part is getting that 10 spline input shaft to line up. Quote Selected
Oil Leak - Ideas? Reply #14 – January 11, 2018, 12:40:05 PM Does the 4.2 eat head gaskets as fast as the 3.8? Quote Selected
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