oil pressure emergency advice

[taxspeaker]

Hey guys I am 4,200 miles into this Alaska trip. The car is running great, no engine temperature issues or valve noise. When I left home I had put in Brad Penn High zinc 20W50 synthetic oil. I had it changed at 3,000 miles in to the trip with a 5w30 synthetic of a good quality. I have consistently been using 1 quart per every 400-500 miles. The last 12 quarts I added were some of the original Brad Penn 20W50 which is mixed with the 5W30. My oil pressure is fluctuating and dropped all the way to 10psi about 20 minutes ago at the end of todays 350 mile mountainous travel. I am in a hotel in the middle of Haines Junction Alaska and am concerned about whether to push on tomorrow or not. One part of me says it is the mixing of viscosities, plus the lower weight that is causing pressure to drop. Pressure does not drop any when I decelerate, if anything it stays the same. When I accelerate it will go back up a little but in the early part of the trip with Brad Penn Oil I was reading 35-40 psi and now it is 18-20PSI except when it drops.
The dropping is occurring late in the day after a ton of driving. The gauge is an original Chrysler rebuilt a few months ago with a new sending unit 2 years ago. Any comments appreciated-tomorrow is schedule at 500 miles to Fairbanks. Thanks

[A383Wing]

if you can, put a mechanical gauge on it and see what it says....that will tell you which way to go next

[nascarxx29]

If you have access to real gauge you can tap in next to original pressure sender,you temp is not rising and your not hearing valve lifter noises.but a real reading would be most accurate..then you would know for sure.anything from oil pump oil filter might cause flucuations

[nascarxx29]

http://board.moparts.org/ubbthreads/ubbthreads.php/ubb/showflat/Number/5929187/site_id/1#import

[Alaskan_TA]

I agree, hit the parts store & install an actual pressure gauge.

If you get the right fittings, including a tee, you can mount both & compare them.

One of my rigs had oil pressure that would drop down to 10, then zero after 10-20 minutes, but the actual pressure gauge proved it a liar. Thousands of miles later, the aftermarket gauge still works right & the other one still lies. Hopefully you discover the same thing.

[cdr]

if you are loosing pressure it is probably the crumbling valve stem seals that have plugged up the oil pick up screen , that is likely the oil consumption problem,, the seals are in the oil pan,, in this case i have removed the oil filter & the hole NEXT to the threads on the oil pump goes to the screen, remove drain plug & get a blow gun & blow in the oil pump hole , at about 50 psi & it will remove most of the valve seal material.

THIS IS JUST A GUESS TO WHAT IS WRONG!!!!!!!!!!!!!!!!!!!! but have seen it many times on old engines

[nascarxx29]

Original nylon alum timing gears
 factory units

can end up in the sump pick up

[cdr]

Original nylon alum timing gears
 factory units

can end up in the sump pick up

THIS ALSO!!!

[birdsandbees]

Now you've got him terrified!  

If he has oil pressure all day and then it slowly drops later on I'd almost suspect he has a sender heating up throwing it's resistance off, if the motor isn't overheating, oil consumption isn't changing etc. Only way to know for sure as has been pointed out.. get a mechanical gauge on there if you can.

My 'Bird shows pathetic oil pressure on the electric gauge, not a whole lot better on a real gauge either but I've driven it across most of Ontario numerous times and 26 years later the engine still doesn't knock.

I'd also never run 5W30 in a 440HP and if anything the 20W50 should be showing a higher pressure as you get more of that in the sump than the 5W30, so something has changed.

[taxspeaker]

Ok what about this-I am in a community so small there is no auto parts (or any other type) of store, but there is a mechanic shop. I have been thinking about what is changed-I did 15 miles of deceleration down the Chilkoot pass today. Idling and deceleration are notorious for poor fuel burning and I had the lowest quality fuel in the world all day for 3 days. COmbine poor fuel, deceleration & high temperature together in an engine that already is burning some oil and you lower viscosity. Add in high engine oil temperature (not water temp) from the climb back up the mountain pass and you make the viscosity worse with a hot gauge. I am thinking about waiting for the mechanic tomorrow, see if he has a manual gauge, change the oil and filter and seeing where things are then. I am 110 miles from a cab/rental car/airport and am thinking my options are:
1. Do the above and continue if things look ok-I do not want to end now even though I technically got in to Alaska today at Skagway, or
2. Do the above and drive back to the nearest city 110 miles away,
3. Hire a tow truck and tow it back to that same city
WHat do you think-he doesn't open until 9 PDT

[nascarxx29]

How miles are on your motor,Has it ever been rebuilt or untouched original

[taxspeaker]

The engine has 5,000 miles on it-of which 4,000 came this week. It was rebuilt years ago and sat in a museum before I bought it

[70 sublime]

Is it numbers matching ?

[nascarxx29]

Reads as numbers matching.http://www.dodgecharger.com/forum/index.php/topic,78446.msg881690.html#msg881690

[70 sublime]

Well if it is numbers matching motor I think the first thing I would do is get a mechanical gauge on it to see what is happening for sure then decide where to go from there

[Arnie Cunningham]

5w30 is too thin for these old motors, as has been said 20w50 works well, if you can't find anything else try for rotella 15w40, my guess is they have some because so many of the diesel guys run it,  unless the gauge goes to zero at idle I would drive it, also don't be afraid to be a quart over full, the windage tray will help keep it from frothing
Just my opinion, hope all works out well

[MoParJW]

About mixing different oil viscousities, I once asked someone from Mobil tech support about it, he told me the last number must be the same of the oils you want to mix.
For example you could mix 10W40 with 15w40.
He told me if the last numbers don't match, you could risk the different viscousities not blending properly, I tried to blend 15w40 & 20w50 in a plastic cup and found this to be true.

[moparstuart]

5w30 is too thin for these old motors, as has been said 20w50 works well, if you can't find anything else try for rotella 15w40, my guess is they have some because so many of the diesel guys run it,  unless the gauge goes to zero at idle I would drive it, also don't be afraid to be a quart over full, the windage tray will help keep it from frothing
Just my opinion, hope all works out well

i agree get the ALL brad penn 20/50 back in the motor  asap   or if you dont have  get 20/50 racing valvoline in it ,  the racing have more zinc  and most parts stores carry it

[taxspeaker]

Thx for comments. Awaiting tow truck from 120 miles away. If someone texts me I can send you the best picture ever taken of a superbird. It is in front of emerald lake on Klondike highway to Skagway with snow caps and streams behind. Breathtaking! I can't shrink size in phone for web posting but I can text it. My number is 502-552-5161
Trip still not over but temporary delay until I figure out oil pressure. I agree probably valve seals blocking oil pump because I began smelling exhaust 2 days ago and wondered at the time about valves

[birdsandbees]

I still think it just needs that mess of oil drained and refilled with any good 20W50. Do that and then get a gauge on it at the same time. Good luck!

[moparstuart]

I still think it just needs that mess of oil drained and refilled with any good 20W50. Do that and then get a gauge on it at the same time. Good luck!

i agree  im not even thinking the mess is clogged on this fresh of a motor  ,  Put a good thick oil back in it and I bet the oil pressure goes right back up ,   I have a Direct Connection High Volumn  pump on mine  as long as the motors cool inside it runs 60 to 70 pounds even at temp , if it get hot 200 plug it drops to around 40 ,  with a standard pump i could see it dropping to 20 with thinner oil and warmer temps .    
 For peace of mind in the future i would run a High Volumn pump on the thing !!!   and its easy to install  what 4 bolt and external .

[Pete in NH]

I still think it just needs that mess of oil drained and refilled with any good 20W50. Do that and then get a gauge on it at the same time. Good luck!

I have to agree with this. These old engines have fairly wide clearances and that thin 5-30 oil when it gets hot just isn't going to hold oil pressure very well. Today's engines with tight tolerances might get away with thinner oil but even in these engines light weight oil is more of a fuel economy gimmick. I've never run less than 10-40 in my 71 383.

[70Sbird]

Just my   and I have enough goofy problems of my own to keep me busy and confused but....
I suspect that the sending unit is the most likely culprit. I would find a cheap aftermarket gauge and simply mount it under the hood somewhere ( to avoid trying to snake the nylon line into the car) and simply verify what pressure you are actually are making when hot at idle compared to the gauge in the dash. I would also agree on an oil an filter change, the oil to just get a consistent viscosity back to a known and a filter to possibly remove any contaminates. that may have broken loose in the last 4,000 miles. Since the engine appears to be running fine with no lifter clatter I'm betting that you do have oil pressure.
Check it out an let us know what you find!
Scott

[moparstuart]

Just my   and I have enough goofy problems of my own to keep me busy and confused but....
I suspect that the sending unit is the most likely culprit. I would find a cheap aftermarket gauge and simply mount it under the hood somewhere ( to avoid trying to snake the nylon line into the car) and simply verify what pressure you are actually are making when hot at idle compared to the gauge in the dash. I would also agree on an oil an filter change, the oil to just get a consistent viscosity back to a known and a filter to possibly remove any contaminates. that may have broken loose in the last 4,000 miles. Since the engine appears to be running fine with no lifter clatter I'm betting that you do have oil pressure.
Check it out an let us know what you find!
Scott

[RECHRGD]

Yes, sending units can do some wacky things.  Mine was leaking a few weeks ago so I replaced it with a NAPA unit.  With the new unit it now reads from 15 to 30 pounds.  The old unit read from 35 to 65 pounds.  I always run 20/50 Valvoline racing oil......

[moparstuart]

Yes, sending units can do some wacky things.  Mine was leaking a few weeks ago so I replaced it with a NAPA unit.  With the new unit it now reads from 15 to 30 pounds.  The old unit read from 35 to 65 pounds.  I always run 20/50 Valvoline racing oil......

  me too

[skip68]

That picture is beautiful.   
I tried to resize it and post it but can't get it to post either.   
Hopefully you get some good news today and it's nothing major.   

[taxspeaker]

Bad sending unit trip resumes tomorrow!

[skip68]

  That's good news.   

[BigBlockSam]

 

[hemi68charger]

I once thought I had a similar problem. Turned out when I pulled the sending unit, there was RTV debris obstructing the inlet orifice into the sending unit.... Removed, good to go.......