Rear Main Seal Leak & Fuel issue - related?

[RealJakeMalloy]

Bronco has a rebuilt 302 with about 5,000 miles on it over the last few years. Been running great - especially the last few months. Highway driving, backroads, etc. Today on the highway about 10 minutes into the ride she starts to shutter like she is running out of fuel. I was able to get off the highway but after about another 100 years she cut off. I was able to restart but same thing happened again and I noticed the oil pressure going to 0. When I was able to pull over I pulled the dipstick - dry. No idea why - no leaks of any kind in the recent past.

I put in 6 quarts of oil in hopes of being able to get it to a nearby shop. Starts up and we get about another mile when it happens again - shuttering like it's out of fuel and cuts off. This time it happened going up a hill. Only now I see a leak from under the truck. I get it towed to a local shop who says two things:

1. Rear main seal leak - he won't work on it. Too much hassle.

2. The turning off is unrelated to the leak - also won't work on it.

Charges me $180 for this and tells me to take the truck. I live about 5 min down the road so I assume I can get home with the truck full oil - only it happens again. This time it is clear it is related to the fuel system. The truck is leaking but when it starts the oil pressure is 50 and holding steady,

If I wait long enough it will start and get about 1000 yards give or take. I am ALMOST home - about 200 yards away but I live up a big hill. I made it 75% up the hill and it cut off again. I think I am close enough to tow it to my driveway with my Land Cruiser.

Is there any obvious fix? Is the leaking main seal related?

I am not mechanical at all although I will say Gemini diagnosed both issues right away.

PS: - anything to be concerned about towing it up a hill for about 100 yards? I have holes to put hooks onto the frame.

 

[jeffncs]

Towing - Use a good tow and towing point on each vehicle, Pur someone in the drivers seat to hold the brake and shift to neutral. Slowly draw the tow strap tight. Gently pull the bronco up the hill and have the bronco driver release the brake and steer. Don’t let your bronco driver slam into the back of the tow vehicle!

 

[jeffncs]

Oil leak and fuel issues should be unrelated. They’re separate systems hat shouldn’t overlap.

What year engine do you have? Earlier engines have a 2-piece seal that’s easier to replace. Later model engines have a 1-piece seal which means the transmission has to come out.

Fuel system carb or EFI? Mechanical fuel pump or electric fuel pump?

 

[Broncobowsher]

Should be unrelated. Sounds a lot like a clogged fuel filter.

But, if it was run enough without oil, the engine could be starting to seize. I've rolled a rod bearing over and remember the engine bogged down a bit like it was running out of fuel for a moment. So it may be related. When you have the pan off doing the rear main, better pull some bearing caps and look at the bearings.

 

[RealJakeMalloy]

I am not mechanical - so I need it fixed. But first thing is to get it home. I have a Holly Carb and a rebuilt 302 on a 1976 Bronco that I have owned for about 30 years.

Is fixing a clogged fuel filter a job a novice can learn to do?

 

[Shimmy]

tow it to the shop you normally take it to?

 

[RealJakeMalloy]

Read the post from the start - but in looking at various videos online it seems changing a fuel filter is easy to do - I am sure I can do it. No idea if this is the issue but likely worth doing either way.

 

[bronco italiano]

where are you located?

 

[RealJakeMalloy]

Encinitas, CA

 

[Shimmy]

Read the post from the start - but in looking at various videos online it seems changing a fuel filter is easy to do - I am sure I can do it. No idea if this is the issue but likely worth doing either way.

i read it. i just assumed you towed it to the closest shop, not the shop that has done your maintenance or mechanical work in the past. i assumed you have a shop do your work since you stated a couple times you weren't mechanical AND are asking if changing a fuel filter is a novice job.

either way it sounds like you need to find a shop that can address the oil issue

 

[RealJakeMalloy]

i read it. i just assumed you towed it to the closest shop, not the shop that has done your maintenance or mechanical work in the past. i assumed you have a shop do your work since you stated a couple times you weren't mechanical AND are asking if changing a fuel filter is a novice job.

either way it sounds like you need to find a shop that can address the oil issue

I towed it to the shop where my oil was changed 100 miles ago - they are the shop that refused and then quoted me $8K to fix it or $20K for a new motor. It sounds like there is an option to drop the oil pan. Alternatively, I can just make sure the engine is lubricated each time I drive it and while messy and maybe annoying won't kill my engine -- or so I have read.

I am going to see if the fuel filter is the culprit for the ability to drive the truck at all.

And yes, I would LOVE a shop within 50 miles that works on these old trucks but it seems to range from incredibly rare to nonexistent.

Time to learn how to work on the truck, I guess?

 

[Jetfixr320]

Is it Fuel injected or have a electric fuel pump? If so, it is possible that whoever built it, did it correctly and installed a oil pressure switch that will that will cut power to the electric fuel pump to prevent the engine from running with 0 oil pressure.

 

[RealJakeMalloy]

Is it Fuel injected or have a electric fuel pump? If so, it is possible that whoever built it, did it correctly and installed a oil pressure switch that will that will cut power to the electric fuel pump to prevent the engine from running with 0 oil pressure.

I don't know which it is to be honest. But once the truck is running and the pressure is at 50 why would it cut off - even if there was this kind of kill switch? The issue seems to be little to no fuel getting from the tank to the engine other than what is stored in the carb?

 

[Master Chief]

I put in 6 quarts of oil in hopes of being able to get it to a nearby shop.

Just making sure that I read this correctly. The engine died. You checked the oil and it was not showing on the dipstick so you added 6 quarts.

As for sputtering and shutting off, it may be a fuel issue, or fouled spark plugs.

Regarding the oil, has the engine developed a knock from oil starvation leading to bearing failure? If not, you may have been a quart low or so for it not to be on the dipstick. Adding six quarts to the existing quantity will raise the oil level far above the requirement of the engine. It cannot run properly because the crankshaft is spinning in the oil. The high level is also the most likely cause of the rear main leak.

I would first drain the oil and put in only five quarts.

Second pull and inspect a few spark plugs, clean as necessary, gap check and reinstall. If they are fouled, find out why on such a low mileage rebuild. First place is make sure your PCV system is functioning correctly.

Third, check or replace the fuel filter. If the filter is dirty, I would inspect the fuel bowls to make sure no debris made it past.

Once you having it running, warm it up. May sure you’re parked on a level surface and check the oil level, service as needed.

 

[eBronc2]

So, the shop that changed the oil, is also the shop that "diagnosed" it, but they decided it wasn't "worth the hassle" to repair either the oil leak, OR the fuel delivery problem.....but had no issue charging you almost $200 to tell you that, and told you to take the truck away.

Sounds like you should have told him it's "too much hassle" to pay him for not doing anything.

 

[RealJakeMalloy]

Just making sure that I read this correctly. The engine died. You checked the oil and it was not showing on the dipstick so you added 6 quarts.

As for sputtering and shutting off, it may be a fuel issue, or fouled spark plugs.

Regarding the oil, has the engine developed a knock from oil starvation leading to bearing failure? If not, you may have been a quart low or so for it not to be on the dipstick. Adding six quarts to the existing quantity will raise the oil level far above the requirement of the engine. It cannot run properly because the crankshaft is spinning in the oil. The high level is also the most likely cause of the rear main leak.

I would first drain the oil and put in only five quarts.

Second pull and inspect a few spark plugs, clean as necessary, gap check and reinstall. If they are fouled, find out why on such a low mileage rebuild. First place is make sure your PCV system is functioning correctly.

Third, check or replace the fuel filter. If the filter is dirty, I would inspect the fuel bowls to make sure no debris made it past.

Once you having it running, warm it up. May sure you’re parked on a level surface and check the oil level, service as needed.

Thank you. Yes, you have the sequence correct. I think it took a bit for the added oil to get thru the system but it shows full now. I am not mechanical so will try and figure these items out but first think is to get it home and on flat ground. I only want to tow it once more - to the shop that will do the actual work.

 

[RealJakeMalloy]

So, the shop that changed the oil, is also the shop that "diagnosed" it, but they decided it wasn't "worth the hassle" to repair either the oil leak, OR the fuel delivery problem.....but had no issue charging you almost $200 to tell you that, and told you to take the truck away.

Sounds like you should have told him it's "too much hassle" to pay him for not doing anything.

Yes - 100%. I should call Chase to contest the charge.

 

[markatherton]

Beach City Broncos El Cajon, Ca.

 

[ntsqd]

Towing - Use a good tow and towing point on each vehicle, Pur someone in the drivers seat to hold the brake and shift to neutral. Slowly draw the tow strap tight. Gently pull the bronco up the hill and have the bronco driver release the brake and steer. Don’t let your bronco driver slam into the back of the tow vehicle!

In any kind of braking needed situation while towing like this the BRONCO driver is the brakes, FJ provides the power, Bronco is the brakes. Both drivers need to be on the ball.

I don't think that shop would doing any further work for me! Looks like there is Bronco specific shop not all that far away from you.

 

[Master Chief]

See post 18 by Mark. You should have it delivered to him.