FE Power Forums
FE Power Forums => FE Technical Forum => Topic started by: mil9657 on November 26, 2019, 08:55:16 AM
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Hi, I'm having a strange problem maybe you guys can help me out with. I have a 1972 f100 with a 360 in it, while driving home from work last week the oil pressure gage went to "L". I did notice a lack of power when going up hills as this was happening but no other out of the ordinary things. The truck has always ran towards the low side even after I replaced the oil sending unit. Once I got it home I parked it, didn't check the oil until the next day and it didn't show on the dip stick. I decided to drain what oil that was left ( 1 to 2 quarts ) put a new filter on and fill it back up.
The truck started up and ran fine other than smoking a bit, it hadn't done that before. I drove it maybe 5 or 6 miles and the oil pressure was good, better than I had ever seen it. So a day or so later I drove it about 12 miles at a constant 60 mph. Around about 10 miles I noticed the oil pressure gage started heading towards "L" and the just flat lined. The truck lost power but I was able to limp to a parking lot.
I looked under the truck and noticed oil dripping from the bellhouseing. I checked the oil and it was not showing on the dip stick again. I let the truck sit for an hour and checked the oil again now oil was on the dip stick up to the full mark. Started it back up drove it back home and the same thing happened again lost oil pressure and power. I lipped it home to the garage and there it has remained.
I took the valve covers off to check for any obvious signs of obstructions in the oil return passages but could find none. What do you think is going on with this thing? Thanks
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The fact that the oil level went from not showing on the dipstick to reading full indicates you have serious drain-back issues. If the engine is all original and stock, I'd guess you have busted pieces of valve stem seals blocking return passages somewhere. While they usually block the return passages at each end of the heads, they aren't always easily seen if they are down in the passage a ways. It could also be sludge build-up in the passage as it goes around the head bolt. It's a tight area that needs to be clear, and any obstruction will hinder oil return pretty drastically. Or it could be a combination of the 2...which is not exactly uncommon for an original engine with that amount of age on it, especially with the use of older oils and possible lack of regular oil changes at some point through its long history.
It also sounds like you have a leaking rear main seal on the crankshaft, which is likely where the oil from the bellhousing is coming from. At this point, I'd say a complete tear down is in order because you likely have some bearing and/or ring/cylinder/piston damage due to oil starvation. Probably not what you want to hear.
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2X on a complete teardown. :(
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I was afraid it would be something like that. Thanks for responding to my post
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Pull the valve covers, clean the returns and see how she does.
If you were happy last week, you'll be happy again :) Sounds like it was filling the valve covers.
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It also sounds like you have a leaking rear main seal on the crankshaft, which is likely where the oil from the bellhousing is coming from. At this point, I'd say a complete tear down is in order because you likely have some bearing and/or ring/cylinder/piston damage due to oil starvation. Probably not what you want to hear.
Another possibility is that since the valve covers are filling up, oil could be leaking out of the valve cover rail where the intake meets the head.... From there it can leak down the back of the block, bellhousing, etc.
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To add to the other comments, it might be worthwhile to try blowing air under pressure down the drainbacks. If they're clogged by stem seal 'swarf', the air might clear them out. That's not necessarily a good result, for the stuff is then more likely to get stuck on the screen on the pick-up tube and cause obstruction there. But since it won't cost anything except the possibility of rocker cover gaskets, it might give some indication of what's going on.
KS
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Take a good strong flashlight/LED light and shine it into each valve spring and look for a missing valve stem seal. If you see one, take a shop vacuum and rig up a small tube to the vacuum hose and vacuum out the oil drain holes in each end of each head. You will hear the part unplug if it isn't already in the pan. If you have access to a bore scope, run it down each oil return hold in the ends of each head. There are several options to try to find the reason why the oil level changed. Joe-JDC
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I'm with Joe - first thing I'd try is the shop vac and a kludge of reducers to get a 1/2" hose over the oil returns and see what comes up. Valve covers seems like the only logical place for that much oil to hide for that length of time. Old valve seals in engines dry out and shatter like glass.
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I don't disagree with continuing to run the engine if it's cleaned out and pressure returns, I see engines ran dry on oil all the time where I work, but when you lose power due to lack of oil pressure, that means things are getting tight. The engine is living on borrowed time at that point. I know it might seem ok at first, but it's a matter of "when", not "if". But if it's just a point A to B truck, I guess you've got nothing to lose if it starts knocking or is down on power.
Can you even tell when a 360 is down on power? ;D ;)
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Just as a note on how much you can get away with on "0" oil pressure, back in '95 I both a '78 LTD, for the 302 engine core. It was almost 30 miles from my place. The engine ran great but the oil light was on and there was valve clatter. I reved it and there was no knocking, what so ever so, since it was going to be just a core, I decided try to drive it home, keeping it under 40 mph. Got home w/o any knocking. I figured if it started knocking, I'd call a tow truck.
When I pulled it down, I found that the alum/nylon, timing sprocket had lost some nylon and that the hex drive was twisted off. There was a small gap in the oil screen and I found the nylon in the pump BUT, all the crank journals where fine and worn only .001, after polishing them. I used the crank, as is!!
Very hard to believe, I know but, it DID happen.
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When I was at Ford, we sent a new employee to a meeting in Toledo, in a company pool car. Apparently, at the start of the 70 mile return trip, the oil light came on, but "the engine sounded fine". As soon as the Tempo (ugh!) got up on the lift in the X-Garage, the missing oil drain plug became apparent.
Our vehicle coordinator, Ralph, knew where this car was going at the end of its six-month stint in the pool. Executives could buy the six month old pool cars at steep discounts. This particular executive was a known ass. Ralph could have easily had a new engine swapped in, but instead he had the mechanics install a new drain plug and top up the oil.
We never heard a thing about it. The car drove fine for the rest of its time in the pool.
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I advised a total tear-down for one reason: It's a lot cheaper to throw a mildly damaged engine back together (better if no machining is needed and one got really lucky!) than one that ends up with spun bearings, a badly damaged crank, maybe a rod through the block's sides. etc.
Hey, even finding FE parts is getting hard to do let alone all the time it would take to line up and get shipped the needed parts. Throw in machining and the rest and one maybe could have avoided a lot of pain.
And yes, I've also seen a few zero oil pressure engines come back to a long life with a minimal correction (just re-filling the near empty crankcase is a good idea!). Yet, more than that did end up locked-up with a severely damaged engine.
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Bob and others, I was not disagreeing with your assessment about rebuilding, merely trying to help with determining what is the root cause of the loss of oil pressure, and oil. If that can be determined and it is reasonable easy to fix, such as valve job and new seals, or dropping the pan and cleaning it and the screen, then a work truck can be kept in service. A daily driver is a little different for most of us than a weekend warrior FE. I personally would be pulling the heads and pan and checking bearings, and getting a valve job, as well as new timing set as a minimum. Joe-JDC
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Bob and others, I was not disagreeing with your assessment about rebuilding, merely trying to help with determining what is the root cause of the loss of oil pressure, and oil. If that can be determined and it is reasonable easy to fix, such as valve job and new seals, or dropping the pan and cleaning it and the screen, then a work truck can be kept in service. A daily driver is a little different for most of us than a weekend warrior FE. I personally would be pulling the heads and pan and checking bearings, and getting a valve job, as well as new timing set as a minimum. Joe-JDC
Joe, you're good here! I fully agree one must find the root cause of why this happened. I'll add that if the engine has lots of miles, then yes, a teardown to the short block is a good idea as then one can determine how much more (or less) work and parts may be needed.
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Around about 10 miles I noticed the oil pressure gage started heading towards "L" and the just flat lined. The truck lost power but I was able to limp to a parking lot.
Started it back up drove it back home and the same thing happened again lost oil pressure and power.
Doug touched on this. My biggest problem with this situation is here. Lost power- TWICE......Not normal at all. If fuel and ignition were not a factor, then it sounds like the damage has already been done. I don't mean to sound like a pessimist, but the fact is the bearings and pistons probably have excessive wear and will only continue to get worse. I would recommend at the least to pull the pan and check a couple bearings. If you see any discoloration on the crank/rods, it's game over. You could cut the oil filter open too, that would show if there is something seriously wrong before dropping the pan....
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i dont know if running 6 quarts of oil would help or hurt.maybe it would keep a little extra in the pan while driving.
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Yes, you can get away with alot of things in a pinch as people have listed. No noise you say? You may be in luck then. Personally, that info and this time of year, first I would pull valve covers and look at seals, gaskets and ect. and down your drain back passages for obstructions and things you can't get then pull the intake, a pain in the *** but cheap enough. Second, I would cut filter open looking for bearing material sense it obviously ran low oil. Third you will need to pull the pan as there will be debris that made it through and will stop up the oil pump pick up screen and you can check bearings and clearances. P.S If all checks out ok (bearings), good time to throw a pump on and run with a extra quart and your good to go for a while until better weather and you can start collecting things you will need for complete build.
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Had problems before with valve stem seals going past the screen and causing the oil pump to seize and break the shaft.
Some of the Ford OEM screens have a bypass flap which opens up if the screen clogs. This allowed the broken seal into the pump.
Unless you want to risk this happening on the road, suggest you rebuild.
The light goes on when oil pressure is low, which does not necessarily mean no pressure. Having no oil pressure may cause a lot more damage because no oil will be going into the bearings.
If you do not want to go to this extreme, at least pull the valve covers and used a coat hanger or stiff wire to clean the drains from the head to the lifter galley. I have done this in the past on old engines and used kerosene to clean the heads and flush everything through.
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If your returns are blocked and the top end filling with oil then it is possible your loss of power is too much oil being sucked into the PCV and diluting the fuel mixture.
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Y'all can probably quit posting to this thread. It has been a week since mil9657 posted this question. He has a total of two posts since joining the forum. He hasn't acknowledged any of your contributions. If I had to guess, I would say mil9657 is a posthole.
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Y'all can probably quit posting to this thread. It has been a week since mil9657 posted this question. He has a total of two posts since joining the forum. He hasn't acknowledged any of your contributions. If I had to guess, I would say mil9657 is a posthole.
Yes, you may be right. It is somewhat frustrating not to hear back from a poster about the issue. Not just here but on other sites as well. Hey, we all tried!
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The light goes on when oil pressure is low, which does not necessarily mean no pressure. Having no oil pressure may cause a lot more damage because no oil will be going into the bearings.
I've never checked in any of the FE powered trucks, but my 73 F350 (has a factory installed 460) the gauge reads on the low line of normal and the light is off at it has 3psi at hot idle on a verified mechanical gauge and I would certainly consider 3psi with 15w40 low in my book! So if the light was on while at higher RPM than idle it probably isn't good, although there could still have been some pressure.
But at the end of the day it's all a guessing game until parts start coming off. I'd listen to some of the advice given here and start with the easy stuff like pulling valve covers and then intake. If there isn't anything obvious there then if you don't want to risk ruining rebuildable core castings I'd pull the engine and tear it down. Based on what you find at that point decide if you can/need a rebuild.
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If it lost power then there is definite damage. I think, like others, your returns got clogged and all your oil went upstairs.
You may have some miles left if nothing seized or started knocking but the life is likely been reduced drastically.
They lose power due to friction.
I ran my 360 two days with no oil pressure....probably close to an hour total in two separate 30 minute intervals. I went to put the headlights on and boom, lost my headlights etc. Thought I had a ground go bad, backed up with some other things. Unfortunately all I had were two electric gauges and both running off same circuits. My assumptions cost me a motor. The motor did not have long left to begin with but I hated to ruin it. It started not taking fuel, sputtering, then smoking, then knocking. In the end it seized and would not turn over....ironically it got me home. Somehow I figured out if I could keep the RPM's in a certain range she would run...so home we limped at a steady 30 mph slipping and sliding. It would have been a long cold walk in the 4" of snow/ice we only get once a year!
Good luck.
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If you have 3psi at idle and oil in the pan you have likely wiped out the rod and main bearings.
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If you have 3psi at idle and oil in the pan you have likely wiped out the rod and main bearings.
If you are referring to my 73 F350, it's been like that since I bought it (maybe 6 years now?). If it isn't hot (like after a trip to my driveway from the gravel pit with 10k lbs in the bed) then it has around 8-10 psi. When it's been worked real hard it's got less, but the gauge isn't real accurate below 10. I drove it 3 or 4 years with just the factory oil gauge that showed right on the low line. Then I put a mechanical gauge in it and now I wished I hadn't. But it just takes about 300 rpm off idle to bring the pressure up. Talked to the shop that rebuild the engine and was told they ran a std pump but larger main and rod clearances knowing it was a heavily loaded work truck. As far as I know the engine was built in 1983, still running just fine - used not long ago to haul in a bunch of asphalt grindings to fix the end of the driveway.
(https://live.staticflickr.com/65535/40772896193_f6ea061571_b.jpg) (https://flic.kr/p/257XKwR)20171107_121033 (https://flic.kr/p/257XKwR) by Patrick Oilnut (https://www.flickr.com/photos/156200076@N06/), on Flickr
I'm not saying it's the right way to build an engine, or that I like what it does, but it's lived a LONG time like that. The only signs anything is wrong is all the old school valve seals long ago turned to powder so it smokes bad at an idle. For the cost of the truck and the once a month it gets driven on average I'll just keep filling the oil and checking the gas. It isn't a 1200hp Kaase race engine.
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Y'all can probably quit posting to this thread. It has been a week since mil9657 posted this question. He has a total of two posts since joining the forum. He hasn't acknowledged any of your contributions. If I had to guess, I would say mil9657 is a posthole.
Yes, you may be right. It is somewhat frustrating not to hear back from a poster about the issue. Not just here but on other sites as well. Hey, we all tried!
It is the same when you take time out to measure and send photos of parts and the kid (not the op) assumes his time is too valuable to give a simple thanks or no thanks.