Smoke and oil pressure question

[forklift]

I just took my truck out yesterday for its first major drive since I brought it home. When I initially drove it the 300 miles from where I bought it, I had the top on and it was kinda dark, so I didn't notice how much smoke it blew. Yesteday I took off the top and drove it all over the place, but I can't beleive the smoke. It is a non-turbo (I've seen some posts where people said they smoke more) and I'm running straight deisel. I'm woundering what is normal. there is a blackish line of smoke as far behind me as I can see. This has also made me a little nervous about my oil pressure that runs at the first tick mark above zero at idle. Is that normal?? any help would be greatly appreciated. thank you, jake

 

[Big Mike's Motor Pool]

my truck usually runs 60 psi when cold and 30 when its hot at idle

 

[Westech]

ouch man, the multi should run around atleast 20 psi at idle. First off the N/A motors smoke like a, well you know. second, get your self a new sending unit or check the oil psi with a mechanical gauge. thats the first step in checking if you have a proble. Now to cut the smoke a bit I run gas diesel mix. sometimes as high as 50%. it really helps cut the smoke down alot, but you will loose just a tad of power. (less BTU's in gas)

 

[mangus580]

As far as the oil pressure, what range is the guage? If its a 120psi gauge, the first tick would be 30psi, right?

 

[Westech]

you know what mang?

 

[houdel]

Ditto on the double check with a mechanical oil pressure guage. When I brought my Deuce home the guage was acting screwy, showing low pressure, high oil pressure, sticking etc. With only 15k miles on the engine since rebuild, I suspected oil pressure was NOT the problem. So my first step was to install a mechanical guage in addition to the stock guage. I haven't gotten around to fixing the stock guage yet but its on the list of things to do. Right now my mechanical guage reads 45-50 psi idle, 75 psi at road speed, while the stock guage reads 5-10 psi at idle and 30 psi at speed.

Do a search for oil pressure guage, there are lots of posts suggesting possible fixes.

 

[cranetruck]

Here is a confirmation of the above post (image below):


....I know, I need to get a life.

About the smoke, my multifuel was an N/A and it smoked a lot if it was used at low load (=idle) for long periods of time. It was not so bad after a long hard drive. This is true for the turboed version too.

 

[rice]

My 66 oil pressure idles at 40, runs almost 60 on the road. Of course it was a fire truck,only has 3400 miles. It is non turbo, it smokes a lot starting out, but once I get up to speed I don't really notice any smoke unless I hit a hill.

 

[forklift]

I know I don't have a 120psi gauge. I almost thoughth it went too 90, but I've been looking at pictures that show 60, so I was driving today and noticed that when first started and at idle, the truck runs past the half way mark. At speed, it runs near pegged(a little under), and when I lug the gears(which I'll probably be doing for a while yet) it will go below half and work its way back up. I think this is all pretty normal, but after it warms, it drops down at idle. today I saw it sit below the first tick past zero, until I gave it some throttle. It jumped real quick(to me it looked like I caught it not doing its job) and settled just above the first tick. If the picture and text above are accurate, then that means I should be at about 10-15 psi right? I know I need to check this out, but I guess what I'm woundering is should I stop driving it? If it's up while I'm runnig , will it be OK? thanks for all your replys. They are greatly appreciated. jake

 

[Recovry4x4]

I just read in a manual somewhere that 15 PSI is acceptable at idle. General rule of thumb is 10psi per 1000 rpm.

 

[Recovry4x4]

Found it!

Oil Pressure (crankcase main gallery):
Model LDS-465-2
Idle . . . . . . . . . . . . . . . . . . . . . .. . . . . .. . . . . . . . . . . . . . . . . . .OE/HDO-30 at 200°F., 15 psi min
2,800 rpm . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. .OE/HDO-30 at 200°F., 40 psi min

Models LDS-465-1, LDS-465-1A, LD-465-1,
LD-465-1C , LDT-465-1C
Idle . . . . . . ... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .OE/HDO-30 at 200°F., 10 psi min
2,600 rpm . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ......OE/HDO-30 at 200°F., 40 psi min

This comes right from TM 9-2815-210-34-2-1

 

[M35A2]

The first thing you need to do, if you haven't already is to change the oil and oil filters. Get some good quality diesel engine oil flush, enough to treat the amount of oil in your engine. Drain the old oil and remove old filters and replace with new filters and oil.

This makes quite a difference to oil pressure. Then check your oil press gauge again. If it's still doing it, suspect a faulty oil pressure gauge and/or sender unit. I would have thought your oil pump is ok.

Here are some pictures I took of my Toyota Hilux Surf SSRG oil pressure gauge. The first two are in the morning, one at idle and the second at 1000RPM. The second two are in the afternoon after I changed the oil and filter, again at idle and 1000RPM. If you look carefully you can see the difference by just changing the oil and filter.

Do use the engine oil flush though, as it dissolves all the gum and residue that sticks to the inside of the engine over time.

 

[cranetruck]

Jake, you need to tell us if you have changed oil filters lately, also what the level is after sitting for an hour and grade of oil.
These things may have an effect on the pressure.

Make sure the gauge is grounded correctly (image below).

Edit: Andy, I worked on this post before seeing yours..looks like we agree on this.

 

[Recovry4x4]

Another consideration when using engine oil flush is how old the truck is. Remember for the longest times, the military used a non detergent motor oil in their engines. Using a flush on one of these older engines could cause some of that funk to come loose. I had an M54A2C many moons ago that was pretty funky inside as a result of this.

 

[cranetruck]

 

[M35A2]

Another consideration when using engine oil flush is how old the truck is. Remember for the longest times, the military used a non detergent motor oil in their engines. Using a flush on one of these older engines could cause some of that funk to come loose. I had an M54A2C many moons ago that was pretty funky inside as a result of this.

How do you mean "funky" Kenny? Is that an American saying?

I would have thought all engine oil in the 60's didn't have a detergent in, due to technology, or lack of it.

I see what you are saying, but I wouldn't have thought it would cause a problem. The gum is so thick and tar like, that it should just dissolve it, not cause it to come off in chunks. I'm not saying it's a be all and end all solution, but it's an option. It's a process I use at every oil change to clean my engines out. I remember when I got my RAF Defender, I changed the oil without using a flush on the first service and noticed it was very gummy in the oil filter housing etc. The second time I changed the oil, I flushed it out. When I took the filter off this time, the inside of the housing was like new.

 

[M35A2]

Bjorn. I love your book.

Is this the Military issue manual you are using here? I'd love one of those.

 

[rice]

Good oil, changed regularly will eventually dissolve the gunk from the engine. Sometimes cleaners will loosen heavy buildup and cause it to drop in the pan in chunks, which possibly could stop up the pickup up tube. When you change oil, reach your finger in to see if you have sludge buildup in the bottom of the pan. If so, you might consider removing the pan and doing some cleaning.

 

[Recovry4x4]

Sorry Andy, sometimes I write stuff in good ole US slang. Yeah I was referring to that black gunk build up that ocurrs in engines especially without proper oil change regiment. I need to practice my King's English.