Sudden Catastrophic Oil Leak! -- FIXED (bad lower intake manifold seal)

[lobo411]

Additional update:
I retorqued the valve cover and lower intake manifold bolts. The LIM bolts maintained their torque @ 144 in-lbs, but the valve covers required an additional 1/4 turn or so to get them back to 80 in-lbs.

I visually inspected the valve cover gaskets and I felt around the firewall side trying to find fresh oil--nothing, clean as a whistle. Ditto with the lower intake manifold.

I "only" lost 1/4 quart on my 300 mi r/t, which is about what I usually lose. I had 2-3 drips at just about every stop, so I'm guessing that any upper engine leaks I had are corrected. Whatever oil is being lost now is being burned internally, and the few drops I'm seeing are a slow rear main leak.

The rear main probably should be leaking at this point, because the front seal was leaking oil until I replaced it last year while doing the timing chain cover gasket.

The engine is still pinging on hills, so I'm wondering if maybe my 1/4 quart of oil is carbon-ing up the engine. I was planning to switch to a high mileage oil, but I got a good deal on some regular oil so I've been using that. Maybe I'll find a mild additive until I can use up the regular oil I have on hand.

My guess is that the Big Leak was a combination of leaking valve cover gaskets (I used Fel Pro Permadry gaskets and I RTV-ed them like you would a normal gasket. The second set I purchased had a flyer in it saying that using RTV would *cause* leaks), and a leaking LIM due to lack of RTV or prematurely cured RTV in the valley.

UPDATE: Took the car around town. Very little oil leakage--mainly just two drops (one dripping down from each side of the bell housing) after the car is parked and sitting for 30+ mins. I'm pretty sure this is just an existing leak I hadn't noticed before. I may pull the starter to see if I can find any signs of a leaking rear main.

 

[lobo411]

Pulled the starter motor and found the flywheel clean/dry. I also tried retorqing the pan bolts but they were already fully torqued.

 

[lobo411]

OK, last night I cleaned the lower bell housing area. Today...no leaks. Not even a drop over 3 hrs of errands (3-4 stops, where I'd usually lose about 1 tsp-1 tblspoon). Hopefully it was just leftover oil finding its way off the top of the bell housing, and the problem is fixed! Now for my other problem...pinging. Bleh! But that's another thread.

 

[Dono]

Whew!
After living that nightmare, the pinging is suddenly not such a big deal.

 

[rb142]

Run some Techron through it and see if your pinging gets better.

Edit: Never mind. I just saw your other thread.

 

[lobo411]

Run some Techron through it and see if your pinging gets better.

Edit: Never mind. I just saw your other thread.

NP! Feel free to take a look at the pic I just posted of my plugs following the fuel injector treatments. I thought the white stuff was Techron fouling, but maybe I'm wrong. I'd be happy to try Techron again, assuming that that's not what it is.

 

[lobo411]

Whew!
After living that nightmare, the pinging is suddenly not such a big deal.

Heh! Ya, at least the pinging is only an occasional issue. I checked just now and I found a single drop over 3 hrs, but it was mostly oily mud. My hope and guess is that it's just a bunch of crud from the last leak that was just waiting to fall off.

 

[lobo411]

Still leaking a little, but I'm not 100% sure where from. I retorqued the valve cover bolts and it stopped leaking for a few days, but then I started getting a single drop every time I parked. I retorqued the bolts again before my long commute yesterday (they all required about 1/8 turn), but I still got about a teaspoon after parking a few hours upon return.

I found a tiny bit of oil residue on the valve cover to block mating near the rear firewall on the passenger side, but nothing major. Everything else on the upper block is dry. However, the oil drops are all on the driver's side, and I don't see how much oil could be leaking from the lower firewall corner on the passenger side, migrating over the "hump" of the bell housing, and then dripping down the driver's side exclusively.

I'm wondering if I have the same problem as the guy with the dipstick tube issue--excessive blow-by forcing oil out the valve covers. I've been losing/burning about 1 quart of oil every 1200 miles for the last year. I've had pinging on hills for about the same length of time. I've had a film of oil residue that builds up on anything connected to the upper intake manifold vacuum ports--on the brake booster vac line to upper intake connection, on the EGR vacuum line rubber boot, on the PCV valve vacuum line, on the valve cover surrounding the PCV valve, and usually when I pull the upper intake manifold off I get a few drops of oil from the ports. Possibly, this could be forcing oil out of the rear main too?

I replaced the PCV last year and it slowed the rate of this oil film buildup, but it didn't stop it.

Could excessive blow-by due to engine wear be causing additional pressure in the system, blowing oil out of the valve cover gaskets (and causing the bolts to lose torque in only about 30 mi of driving) and leading to a film on anything connected with the vacuum system?

 

[rb142]

It could.

Do a compression test and a cylinder leakdown test and see how much leakage you have into the crankcase.

It is troubling that you are having to torque all these bolts down an eighth turn almost every day.

 

[lobo411]

It could.

Do a compression test and a cylinder leakdown test and see how much leakage you have into the crankcase.

It is troubling that you are having to torque all these bolts down an eighth turn almost every day.

Ya, I'll have to check the garage. I know there are at least 4-5 compression testers in there that I inherited from my dad and uncle, but I'm not sure if they work (IIRC the rubber was in bad shape).

I drove the car around town again today--no leaks. The rundown seems to be:

In town driving, with short 3-4 mile hops on the freeway: no leaks.

Long distance highway driving, cruising at 70-80 mph for a good 5 hrs: leaks.

I know what my Dad's fix would be, after having tried the obvious repairs: put cardboard under the car to catch any drips, keep the crankcase topped off, and have a beer to help you forget about the leak!

Oh and one more fix--start looking for a replacement car for when this one dies.

 

[lobo411]

Well, I haven't got time to do the compression test today, but I did order a new PCV valve tube. I replaced the valve and also put some new generic emissions tubing on it and I was impressed by how loose the old tube was. However, I was a bit worried that the severe angle on the hose might cause an issue, so I decided to buy the Motorcraft molded hose on Amazon for $12. We'll see if that does anything.

If anyone has any recommendations for a nice, conservative oil treatment, I'm still looking for suggestions. I have a garage full of ordinary dino oil (20 quarts at least) that I need to get rid of before I can start using a high mileage oil, so what I'm looking for is something that I can use to approximate using a high mileage oil without going whole-hog into stop leak products.

 

[RomeovilleIL]

Most of the high mileage is nothing more than regular oil with a little leak stop/oil burning additive. CD2 and Rislone have been around a long time and known to work.

 

[lobo411]

Most of the high mileage is nothing more than regular oil with a little leak stop/oil burning additive. CD2 and Rislone have been around a long time and known to work.

Thanks for the tip! I'm going to give Rislone a try...Autozone has a coupon out for double points right now anyway.

 

[lobo411]

K...just threw a bottle of Rislone Engine Treatment into it. I have a fair amount of lifter clatter, so I figured why not. I'll run on that during my long run Wed (300 mi in 5 hrs), change my oil, and then throw in a bottle of Bars Leak Rear Main Seal Repair. Also hoping that my new molded PCV hose will be here tomorrow, and I'm going to run Techron for 2 weeks.

 

[lobo411]

K, the new PCV hose didn't stop the leak, but it does seal a lot better so I guess it was worth the money. One thing--it seems like there's a lot of oil on the PCV valve itself (ie a good sized drop), when every other time I've pulled it it just has oil residue.

I used Motorcraft KCV-98. Fit perfectly even though Amazon said it wasn't compatible for some reason.

Rislone did help my lifter noise--went away almost immediately. I drained the oil today after the Big Run (300 mi r/t in a day) and it was pitch black, so maybe it did clean some stuff out. The oil I drained was only 900 miles old, so it should have been pretty clean.

Installed a new filter and added Bars Stop Rear Main Sealer. We'll see if that does anything.

 

[lobo411]

Still leaking, although I haven't put on the 200 miles Bars Leak is supposed to take to stop a rear main leak.

The valve covers are perfectly dry and perfectly torqued. The LIM bolts are retaining their torque at 144 in-lbs. There is a bit of fresh oil in the area under the LIM/valley area, which is sealed with RTV. Plenty of RTV squished out when I did the gasket.

How much oil really gets up in that valley area? I can't imagine that the leak is still coming from the LIM a second time around--it would be quite a coincidence, and my feeling is there isn't very much oil there in the first place. Just what splashes around, if any.

And isn't the crankcase under negative pressure (lower than the atmosphere)? Wouldn't that cause air to leak *in* rather than oil to leak *out?*

Could oil from the rear main be getting on top of the bell housing?

I guess if it is the LIM, the only thing left would be to try the Chilton's LIM bolt torque spec of 18 ft-lbs instead of everyone else's spec of 12 ft-lbs.

 

[lobo411]

I'm going to try upping the LIM torque to 16 ft-lbs. Kind of annoying that Haynes says 12 ft-lbs and Chilton's says 18 ft-lbs on something that is supposed to be precisely torqued.

 

[rb142]

Direct from the Ford manual, LIM torque:
Stage 1: 8 Nm (71 in-lbs)
Stage 2: 12 Nm (9 ft-lbs)
Stage 3: 16 Nm (12 ft-lbs)

Valve Covers: 10 Nm (89 in-lbs)

Don't trust anything you read in Chilton's or Haynes.

 

[lobo411]

Direct from the Ford manual, LIM torque:
Stage 1: 8 Nm (71 in-lbs)
Stage 2: 12 Nm (9 ft-lbs)
Stage 3: 16 Nm (12 ft-lbs)

Valve Covers: 10 Nm (89 in-lbs)

Don't trust anything you read in Chilton's or Haynes.

Thanks! I stayed up late last night and ended up increasing the torque to 18 ft-lbs before seeing this. Looks like I could bump the valve covers from their current 80 up to 89 in-lbs though.

The engine runs better than it has in years right now. Lots more pep after installing the new LIM gasket, and I don't think I've heard any valve clatter since I ran Rislone through it. If I could just stop the oil leak and get this car through smog in 3 months...well...then I can replace the alternator (bearings are going), the control arms (rubber is gone), and the blend door!

 

[lobo411]

OK, an update. I decided to get a brand new Ford Focus to use as my commuter car one day a week (I average 36 mpg!), but I still drive the Explorer around town 5 days a week.

I dumped some Bars Leak Rear Main Seal Repair into the crank 2 months ago, but it didn't seem to do anything to stop the leak after 500 miles as the bottle indicated. So I decided to dump some Rislone Compression Restorer into the oil too. I stopped paying attention to the leak because it wasn't critical anymore (only driving 3 miles in a trip as opposed to 300), but lately I've been looking for it and it seems to be gone. Who knows which product is responsible or if it's both, and who knows if the leak will come back the minute I go back to just running regular oil. We'll see I guess!