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83 D150 slant six burns a lot of oil.
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Author:  DadTruck [ Fri Nov 03, 2023 6:35 am ]
Post subject:  Re: 83 D150 slant six burns a lot of oil.
The black paint on the 80’s engines makes it hard to find the leak.
My 83 D150 with a tall Wix filter takes 6 quarts at an oil change to get the oil to the full mark on the dip stick. Does the vehicle have the correct dip stick? Maybe you are over filling it?
The oil passage that runs from the rear cam bearing to the rocker arm rail runs through the head gasket, but that head gasket seal area is well within the head gasket perimeter and is not a typical leak area. And if it was the issue it would be leaking all the time the engine is running. it is not uncommon to see an oily film along the pushrod - lifter head to block joint. (just below the sparkplugs) That joint is pretty far away from the head bolts for direct clamp loading, but that is not pressurized oil, that sees only crankcase pressure.

Try power washing the engine and under carriage real good. Drive a couple 100 miles, maybe find an empty parking lot and do some turns and stops then re check with the UV light.
Author:  Rick Covalt [ Fri Nov 03, 2023 8:28 am ]
Post subject:  Re: 83 D150 slant six burns a lot of oil.
Bolt in the alternator bracket goes into the lifter galley. That can run down that side to the oil pan rail. Clean it well, drive it and park it on a large piece of cardboard overnight check go drips in the morning
Author:  Jimmy [ Wed Nov 15, 2023 9:48 am ]
Post subject:  Re: 83 D150 slant six burns a lot of oil.
There seems to be a leak at the head gasket on the back passenger side of the engine. From #5 cylinder to the back. The block is shiney with oil there but it doesn't drip. Drivers side looks good and dry. Alternator, fuel pump, and oil pump looks good. It is hard to see with a black case. Pictures don't show well either.

I have noticed a recent reduction of oil use by about half. I did a piston soak with B12 overnight. Didn't drop right away but the 3rd trip or so after that the oil use is a lot less. Still would like to figure out what is wrong before pulling the motor. I know the problem will show itself or get fixed with new gaskets though.

It still smokes a little when cold. Not at startup, just accelerating. I'm guessing the rings are weak and not wiping the excess oil off until it warms up and thins out.

Thanks everyone. Will update here when/if I get the motor out.
Author:  slantzilla [ Thu Nov 16, 2023 1:20 pm ]
Post subject:  Re: 83 D150 slant six burns a lot of oil.
The head gasket on the passenger side is very narrow along the lifter galley. It is not unusual for them to leak there. You can try retorquing the head, it may or may not work.

I have had good luck spraying the area down with brake cleaner then sealing the area with good silicone sealer until the gasket can be replaced. You also have to be real careful when installing the head because it can catch the gasket in that area and cause a big leak.
Author:  Jase [ Thu Nov 16, 2023 3:19 pm ]
Post subject:  Re: 83 D150 slant six burns a lot of oil.
Quote:
It still smokes a little when cold. Not at startup, just accelerating. I'm guessing the rings are weak and not wiping the excess oil off until it warms up and thins out.

Thanks everyone. Will update here when/if I get the motor out.
I would try the B12 again... or what ever that other stuff is in the white can with red lettering. Maybe put the stuff in, and spin the engine over with out starting it... let it Sit overnight, spin it over some more, and put the rest in the fuel tank.


Also:
I've successfully used "restore" snake oil in a can years ago on a briggs and Stratton powered pavement roller that smoked blue clouds and made people complain of how I smelled like smoke after I sat on it for a morning.. it cut down on the clouds of smoke, it still smoked but more like a two stroke.. (and I didn't want to keep breathing oil smoke for that particular employer)

AND I have used the same In a Mercedes diesel that was tired enough that it would not start below 32*.. with the said snake oil, it will start at 20* if I get the starting procedure just right.
Author:  Jimmy [ Wed Dec 06, 2023 5:49 pm ]
Post subject:  Re: 83 D150 slant six burns a lot of oil.
I'll try retorqing the head. Have thought I should have checked that when I had the valve cover off.

Wondering now if the leak on the passenger side is the distributor. Would it leak a lot? It's the old style distributor. In fact the limited amount of adjustment has the timing advanced 14 degrees at idle. I've thought it seemed like too much but can't retard it anymore. I may pull the distributor this weekend and check the seals. It runs great the way the timing is set.

It smokes very little now. Seems strange but it smokes most after coming to a stop at the light going into town and then after I turn left. Could turning cause oil to slosh and cause oil smoke? After the motor is hot I can make a turn and no smoke.

Plan is to pull the motor over my Christmas break. Have a bad feeling the leak is something weird and after a rering, bearings, and gaskets the oil use won't be fixed.

Have the front wheels and hubs off now. Doing a regrease and new seals.

That is another question. If the front wheel bearings look good do I keep them or just get new? Have koyo bearings now. JL-69349-N inner bearing. Ordered hub seals but they were too small. Measured the sizes and they were seals for an 8 lug hub on the O'Reillys website. Guess the O'Reillys website is off or old dodge parts may be random.
Author:  slantzilla [ Wed Dec 06, 2023 6:15 pm ]
Post subject:  Re: 83 D150 slant six burns a lot of oil.
I had an 83 D-150 for awhile. I ran into the same issue on sheel seals. There are actually 2 different spindle/hubs for these trucks. One is considered light duty for the D-100/Miser trucks. The other is "heavy duty" for the D-150. It can be a pain to find the heavy duty part.
Author:  hank2 [ Thu Dec 07, 2023 1:46 am ]
Post subject:  Re: 83 D150 slant six burns a lot of oil.
Quote:
I had an 83 D-150 for awhile. I ran into the same issue on sheel seals. There are actually 2 different spindle/hubs for these trucks. One is considered light duty for the D-100/Miser trucks. The other is "heavy duty" for the D-150. It can be a pain to find the heavy duty part.
I had a similar/same problem with my '82 D150 when I did some wheel bearings and seals some years ago. There technically was no D100 model for a few years in part of the 80's, but mine is almost a Miser model with 4800 GVWR (bottom of the heap). Anyhow they had 3300 lb. and 3600 lb. front axles. The heavier rating were supposed to be the 8 lug D250/350.

I found that mine, 5 lug of course, took the correct lighter axle outer parts, but needed the 3600 lb. axle inner bearing, race and seal. It's been a while, but I think that additionally that only certain brands fit what I have? I had a list kept of what part no.'s actually worked, but I have no idea what's become of that.
Author:  Charrlie_S [ Thu Dec 07, 2023 3:17 am ]
Post subject:  Re: 83 D150 slant six burns a lot of oil.
Rock auto lists both different front hub seals.
Author:  Jimmy [ Thu Dec 07, 2023 4:13 am ]
Post subject:  Re: 83 D150 slant six burns a lot of oil.
My 83 D150 is a miser model. Looks like it has the heavier front axle.

If the wheel bearings look good after a clean up I'm going to reuse them. My thinking is new bearings are made in china and might be junk. Is a koyo bearing from Japan?
Author:  Charrlie_S [ Thu Dec 07, 2023 4:48 am ]
Post subject:  Re: 83 D150 slant six burns a lot of oil.
I'm glad you guys are posting about these issues. I have a 84 D-100, slant six 833 OD. Have not looked at the front end, yet. I know all the emissions has been removed, the engine has a Super Six 2 bbl (don't know if an option as stock). No lean burn, and the rear has been changed to a 8 3/4 3.91 SG. Wheels and tires are P235-75x15 on Cop Car style wheels. Factory AC, PS, PB. After market cruise control, brake control, class 3 receiver. Engine runs nice. I did pull it to reseal for oil leaks, and put in a new clutch. Waiting on a new Champion radiator (runs warm/hot, but did not two years ago, when I pulled the stock radiator). Hope to have it all squared away to tow my car for the 2024 racing season.
So please keep the info coming on these trucks.
Author:  Jimmy [ Thu Dec 07, 2023 6:17 am ]
Post subject:  Re: 83 D150 slant six burns a lot of oil.
Aftermarket cruise? Who made it?
Author:  Charrlie_S [ Thu Dec 07, 2023 8:07 am ]
Post subject:  Re: 83 D150 slant six burns a lot of oil.
Quote:
Aftermarket cruise? Who made it?
The one on my truck is a Audiovox (long discontinued) Took me a lot of digging to find what it was (nothing labeled/tagged) and get the installation instructions. It was working when I got the truck, but after sitting for a couple of years, no longer working. There are other companies that made aftermarket cruise units back in the day. JC Whitney and Montgomery Ward sold a lot of them.
Here is one on e-bay. I don't recommend buying it, just showing you. https://www.ebay.com/itm/176018707605?h ... R-7u3c-IYw
I have a few NOS Zemco driving computers, one of which does have the cruise built in. (PS: none for sale at this time).
Rostra still makes add on cruise for our non computer carburetor vehicles.https://www.rostra.com/universal-afterm ... rostra.php
Author:  Jimmy [ Sat Jan 06, 2024 4:21 pm ]
Post subject:  Re: 83 D150 slant six burns a lot of oil.
Got the engine out and partially torn down. Lots of pictures to link or post. Should I start a new thread?

Initial observations.

Cylinders are mirror smooth, no gouges.
Think the main leaks were the distributor and oil pump.
Lots of carbon but the sparks plugs still are grey.
.155 to .160 depth from the deck to the piston.
No intake or exhaust gasket I could see. Felpro head gasket.
Can't find my telescoping gauges. Will measure the bore later.
Author:  Jimmy [ Sat Jan 06, 2024 5:17 pm ]
Post subject:  Re: 83 D150 slant six burns a lot of oil.
Slant six tear down https://imgur.com/gallery/4rmWB4J
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