Low oil pressure and runs crappy.....back story

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Topic author
geminiroq
Posts: 17
Joined: Tue Mar 18, 2014 8:42 pm

Low oil pressure and runs crappy.....back story

Post by geminiroq »

Hi Guys,

I recently went through and fixed a few things on my 79 cherk:

* replaced valley pan gasket
* CTO
* EGR
* Thermostat 195 degree
* carb gasket
* fuel filter

Then I had to move it out of my moms backyard and took it to a local mechanic who did the following:

* changed the mechanical fuel pump
* "supposedly" rebuilt the carb
* rerouted a vacuum line that I never saw before that was attached to a thin metal tube that had a spot on the manifold that it used to be inserted into

When I got it back from the mechanic I noticed the following:

* engine feels tight
* engine feels like it is working hard to move the cherk
* stinks like gas
* hard to start
* the oil pressure is low
* engine is getting hot but not overheating.

When I questioned all this this, they said it was fine and that it was an old vehicle but I say that is a whole lot of BS.

What I am most concerned with is the low oil pressure now.

I searched and tried to find some info online and this forum but I couldn't find anything specific to all the problems I listed.

The backstory is....my cherk was sitting for a couple of year....before it was parked it started up right away, ran smooth, had good oil pressure and didn't feel "tight"

At that time it didn't have any known mechanical issues.

On thing to note....when replacing the valley pan...the engine looked really really clean but when I pulled the dip stick after the oil change....there was a glob of sludge on the tip of the stick.

I want to get my rig on the road again and am at my wits end right now and hoping you guys are able to point me in the right direction on fixing my rig.

Thanks...any and all advice is appreciated.
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tgreese
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Location: Medford MA USA

Re: Low oil pressure and runs crappy.....back story

Post by tgreese »

The low oil pressure is most worrisome. It is possible for the fuel pump to leak and put gas into the crankcase. Pull the dipstick, look at the level and smell the oil.

Hot engine temperatures will make the oil pressure lower because the oil thins out, but even then you should have a minimum of 10 psi for every 1000 RPM.

If you worry about sludge, the detergent in modern oils will clean it up pretty well. Look at the sediment at the bottom of the drain pan, and it should get less with a few changes of oil.

It's very hard to own these cars if you can't do the maintenance yourself. If you find a place for service that offers more than indifferent help, it will probably be costly. There is a 1979 factory service manual (TSM) here http://oljeep.com/edge_parts_man.html - all of the engine-top emissions systems are shown there, along with a diagram of the vacuum connections. You have to either learn that material yourself, or show us in pictures what's connected and where. And you'll still need to sort it out, even if you are given helpful advice here.
Tim Reese
Maine beekeeper's truck: '77 J10 LWB, 258/T15/D20/3.54 bone stock, low options (delete radio), PS/PDB, hubcaps.
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csuengr
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Re: Low oil pressure and runs crappy.....back story

Post by csuengr »

That rerouted vacuum tube was the heat source for the automatic choke. The choke uses both electric power and exhaust heat to open. So check to make sure your choke is opening fully. The choke not opening will also make he engine sluggish and lead to a gas smell, not to mention running rich.
1977 Cherokee S, Ford 5.0, 5 speed, BW 1356, 33 x 10.50 BFG's. No longer my DD.
2007 Mercury Milan, 2.3L, 5-speed, now my DD. 29 mpg average.

OssaMAR
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Joined: Sun Jul 22, 2018 7:30 am

Re: Low oil pressure and runs crappy.....back story

Post by OssaMAR »

What weight oil are you using?
20-50 or 0-30?
Try straight 40wt.
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Cecil14
Posts: 727
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Re: Low oil pressure and runs crappy.....back story

Post by Cecil14 »

A good 10w-30 or 10w-40 should be fine, if it is not then there are other internal issues you need to address. Straight 40wt oil is going to be extremely hard on parts on cold starts and until the engine is good and warmed up.


aa
1983 J-10 - 4.6L(MPFI)/CS130D/Hydroboost/NV3550/D300/44/44/3.54/Disc-Disc/32s/42 gallon 'burb tank
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toothofwar
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Re: Low oil pressure and runs crappy.....back story

Post by toothofwar »

I've been running 20w50 in mine for a few years now. On my rebuild I now have around 65lbs of oil pressure on cold starts and a little over 40 on warm idles. But I resurfaced the oil pump housing and replaced the pump gears, spring and valve.

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fsj454
Posts: 378
Joined: Sat Apr 13, 2013 6:44 am
Location: ma.

Re: Low oil pressure and runs crappy.....back story

Post by fsj454 »

I used vavoline vr1 20 50 coventional motor oil. Motor was noisey and sluggish .So I was at swap meet and talked to a amsoil dealer about new products. Amsoil z rod oil 10 30 full synthetic with zinc and all the good stuff for flat tappet cams. I purchased a case for 120.00 .I can not believe how much better my motor runs with Amsoil Zrod oil . :-bd
:fsj:454.nv4500.205.twin stick.hydo boost. hydrolic clutch.dana 60s.soa.37s 17inch.tration bar.warn 1200. 4 wheel disc.aero29 gallon .conferr roof rack.spal pulse width modulation.spal duel fans.painless battery isolator.duel batterys.factory cb. headers 2 1/2 duels.4.56 Detroit locker.alloy 35 spline axles.stainless brake lines .holley 770.edelbrock.fuel.water.intake.H4s.head light relays.racho 9000 shocks.rock ram.steering box brace.j20 steering box.msd8265 probillet distributor.msd super conductor wires.
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Cecil14
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Re: Low oil pressure and runs crappy.....back story

Post by Cecil14 »

fsj454 wrote:I used vavoline vr1 20 50 coventional motor oil. Motor was noisey and sluggish .So I was at swap meet and talked to a amsoil dealer about new products. Amsoil z rod oil 10 30 full synthetic with zinc and all the good stuff for flat tappet cams. I purchased a case for 120.00 .I can not believe how much better my motor runs with Amsoil Zrod oil . :-bd
I've been running the zrod oil since it came out, and the zinc added product they had before that (can't remember the name). I've always been very happy with it. Whether that means anything or not? Who knows. :)


aa
1983 J-10 - 4.6L(MPFI)/CS130D/Hydroboost/NV3550/D300/44/44/3.54/Disc-Disc/32s/42 gallon 'burb tank

Topic author
geminiroq
Posts: 17
Joined: Tue Mar 18, 2014 8:42 pm

Re: Low oil pressure and runs crappy.....back story

Post by geminiroq »

Thank you for the suggestions....I think I will start with another oil change that I will do myself.

I am assuming they used 10w-40 but who knows or what kind.

OssaMAR
Posts: 8
Joined: Sun Jul 22, 2018 7:30 am

Re: Low oil pressure and runs crappy.....back story

Post by OssaMAR »

Yes but 40wt should bring up the oil pressure.

SJTD
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Re: Low oil pressure and runs crappy.....back story

Post by SJTD »

Especially when it's cold as was pointed out above. Why would you recommend that over a multi-weight?
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'84 GW with Nissan SD33T, early Chev NV4500, 300, narrowed Ford reverse 44, narrowed Ford 60, SOA/reversed shackle in fornt, lowered mount/flipped shackle in rear.

mx71
Posts: 246
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Re: Low oil pressure and runs crappy.....back story

Post by mx71 »

Could just be time for a rebuild. Lots of places for old oil to clog places up, be it the timing cover, heads, etc. This was what my motor looked like that I hadn't planned on replacing. Could have had anywhere from 130,000 to 230,000, to 330,000. My guess is 230, but other than everything on the truck just being worn, it was in great shape with almost no rust.:
Image
Image

OssaMAR
Posts: 8
Joined: Sun Jul 22, 2018 7:30 am

Re: Low oil pressure and runs crappy.....back story

Post by OssaMAR »

Running 40wt in an Old motor in the summer is not a problem
If the clearances are large then you need thicker oil.

I use 20-50wt in summer 15-40wt in the winter.

letank
Posts: 4010
Joined: Wed Oct 03, 2012 9:16 pm
Location: SF bay area

Re: Low oil pressure and runs crappy.....back story

Post by letank »

mx71 wrote:Could just be time for a rebuild. Lots of places for old oil to clog places up, be it the timing cover, heads, etc. This was what my motor looked like that I hadn't planned on replacing. Could have had anywhere from 130,000 to 230,000, to 330,000. My guess is 230, but other than everything on the truck just being worn, it was in great shape with almost no rust.:
Image
your guess is good, it all depend on oil type and frequency changes, my 74 w 349K is cleaner than the 85 at 210K, check the back of the pict for the amount of caked oil

Image

Basically any oil is better than old oil. Running rotella 15W40 on the 85, or castrol partly synthetic 10W40 on the 74 when it became avail in the late 90's...
Michel
74 wag (349 Kmiles... parked, next step is a rust free body)
85 Gwag (229 Kmiles... the running test lab)

Topic author
geminiroq
Posts: 17
Joined: Tue Mar 18, 2014 8:42 pm

Re: Low oil pressure and runs crappy.....back story

Post by geminiroq »

Thanks for all the advise!

I will start with the oil.

candymancan
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Joined: Tue Mar 22, 2016 11:32 pm

Re: Low oil pressure and runs crappy.....back story

Post by candymancan »

mx71 wrote:Could just be time for a rebuild. Lots of places for old oil to clog places up, be it the timing cover, heads, etc. This was what my motor looked like that I hadn't planned on replacing. Could have had anywhere from 130,000 to 230,000, to 330,000. My guess is 230, but other than everything on the truck just being worn, it was in great shape with almost no rust.:
Image
Image

That engine is gummed up lol looks like the oil wasnt changed enpugh in it.

When i took my valve covers and oil pan off everything was just orange stained but no grime like that lol dang
1998 Jeep Grand Cherokee 5.9L Limited 219k
1998 Jeep Grand Cherokee 4.0 I6 laredo 430k
1990 Jeep Grand Wagoneer 155k
1976 Jeep J10.. 85k(repaired)

fsj454
Posts: 378
Joined: Sat Apr 13, 2013 6:44 am
Location: ma.

Re: Low oil pressure and runs crappy.....back story

Post by fsj454 »

Looks like coolant passages are plugged up and motor ran at high temp and cooked oil. remove coolant plugs in block and I bet they are full of shut. RADIATOR IS PROBLY JUNKED UP TO. Check con rod rearing for a AM logo and date and that will tell you if it is a verging motor. Will you be doing assembly or someone else. I am in the assembly stage on my 1990 motor as we speak . It takes time to nickel and dime it but in the end you now what you have....
:fsj:454.nv4500.205.twin stick.hydo boost. hydrolic clutch.dana 60s.soa.37s 17inch.tration bar.warn 1200. 4 wheel disc.aero29 gallon .conferr roof rack.spal pulse width modulation.spal duel fans.painless battery isolator.duel batterys.factory cb. headers 2 1/2 duels.4.56 Detroit locker.alloy 35 spline axles.stainless brake lines .holley 770.edelbrock.fuel.water.intake.H4s.head light relays.racho 9000 shocks.rock ram.steering box brace.j20 steering box.msd8265 probillet distributor.msd super conductor wires.

Cheap Hobby
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Joined: Tue Apr 22, 2014 12:53 pm
Location: Central Valley

Re: Low oil pressure and runs crappy.....back story

Post by Cheap Hobby »

Did your mechanic set the timing to factory spec? When I had to do that every 2 years to pass smog my 79 turned into a massive ture. Comment get home fast enough to rest timing so that it was driveable. Also got much better mpg with idle set correctly to run better.
79 Cherokee WT QT Golden Eagle white with gold windows "Pigger" only blows hubs the night before a road trip or the clodest night of year. Has only been towed cause of stupid.

Cheap Hobby
Posts: 649
Joined: Tue Apr 22, 2014 12:53 pm
Location: Central Valley

Re: Low oil pressure and runs crappy.....back story

Post by Cheap Hobby »

Did your mechanic set the timing to factory spec? When I had to do that every 2 years to pass smog my 79 turned into a massive ture. Comment get home fast enough to rest timing so that it was driveable. Also got much better mpg with idle set correctly to run better.
79 Cherokee WT QT Golden Eagle white with gold windows "Pigger" only blows hubs the night before a road trip or the clodest night of year. Has only been towed cause of stupid.
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