PD 4106 8V71 Smokes on Startup
 

PD 4106 8V71 Smokes on Startup

Started by rxeno, February 22, 2011, 10:58:57 AM

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rxeno

Here is a pic of my 1962 PD4106 8V71 on start up. It smokes like this for about 15 minutes (or more) then once it is warmed up it seems to stop. I can take off and run at any speed without smoke. Occasionally my starts are crappy or 3rd gear should have been 2nd and I will get a small puff of white.

I was told a block plug would heat it up and it would stop smoking. :)

Either way, isn't it time for a rebuild? And is this an inframe situation unless something dire is amiss?
Just ran it 65mph on a 1200 mile trip with no problems.
Burned about a gallon of oil maybe a little more.

Filled it and ran around town for about a hundred miles and no oil loss yet.

Very small oil spotting on park.
The dark spot on the ground is water shed of the shell.
This pic is off the backend after the 1200 miles. Not a lot of oil all over it.

Taking it to Motor Trucks in Everett, WA. What should I be expecting as an acceptable estimate on the rebuild cost?

Thanks!
PS Of course the blower will need it too, and the transmission, so I will need to deal with all that.

papatony

   I don't think you have that much of a problem. 8v71s are going to smoke that their nature.  If you went 1200 miles used no more oil than that I would not get into a rebuild mood, you are looking at 8 to ten thousand dollars if its done right.  Keep an eye on your question there are a lot of first class mechanics that can help .  just don't jump the gun.

Len Silva

I wouldn't worry about it.  To me, the best indication of condition is how easy (or hard) it starts.  If it lights off after a couple of turns, compression is good, and that is the best indicator of condition.

Hand Made Gifts

Ignorance is only bliss to the ignorant.

rxeno

Thanks @papatony  That is why I am asking. But 15 minutes of smoke is very disturbing to most everyone so far. Storage made me move out lol.
Neighbors called the fire department the last two times I started her up.

Well, @Len Silva ... she sat for about a week, it was warm weather, and I pulled the switch and she turned over twice and fired up.
But when it is cold here, 38 to 45 degrees, it will take some starter fluid to get her going. I dont like using that but I also am too new to turn her over for a long pull to start up. I read I could fuse some things togethger from the powerful batteries involved.


Ace

If you let it idle at low idle for very long you can expect smoke. If it starts good as in quickly, I wouldn't worry yet abou getting it rebuilt. Keep am eye on your oil pressure both at a dead stop and at speed. My dad used to tell me, ANY pressure is better than none at all!
Ace Rossi
Lakeland, Fl. 33810
Prevost H3-40

eddiepotts

Next time you start it hold down the pedal until you get max oil pressure. Not max RPMs. See if it does not go away faster for you. Do not let it sit and idle for long periods just to let it run.

bevans6

how cold is it where you are?  Whitish smoke is unburnt fuel, so that could indicate a injector problem or a tuneup problem.  Plugging it in will reduce it, as will just driving off as soon as you can.  Not just idling it. 

How is it for smoke after you have driven it for a few minutes? 

Brian
1980 MCI MC-5C, 8V-71T from a M-110 self propelled howitzer
Allison MT-647
Tatamagouche, Nova Scotia

rxeno

Thanks all, yes I am seeing the point now. I am high idling it to "warm up"
So, definitely the smoke goes away after very short driving.
Seemed to depend upon warm up time.

But she sat for 8 years so definite;ly gaskets, fuel injectors all those things are suspect.

The blower needs a rebuild according to a mechanic that looked at her first.
But at $35,000 for the factory rebuild I steered off in another direction.


eddiepotts

That is good. Unless she looks like a new Prevost on the inside, having a shop rebuild everything could really turn you upside down. You may be better off finding a good built conversion that has a good drive train although I doubt you have any real problems. I have only seen mine smoke once but it was about 36* out. It does not normally get that cold here and if it does I have not need to start it.

rampeyboy

First time I started my Scenic up after 5 or 6 months of sitting, it smoked a lot. It had lost prime, and it took this newbie a while to figure that out, but I finally got it. Anyway, it took a few minutes, I didn't count the minutes, but it was scary at first seeing all the smoke. I can't wait to see the campground on a cold morning! Someone else here said they keep going long after being due for a rebuild, so if you don't mind adding oil, just enjoy her!

Boyce
Boyce Rampey
Columbia, SC
Scenicruiser 227

rxeno

Allcomments are greatly appreciated!

Picked her up in california, 70 degrees and smoked for quite a while.
Oil and lube and filters and the shop said, excellent no worries, last for 20 years.

Just spoke with Luke and as noted here, new block plug, fuel injectors, tune up and gasket set and maybe a blower rebuild and we should be in much better shape.

She was a recording studio for 25 years so we are restoring and rebuilding and putting a studio in and then heading for Nashville.

Looks like I am going to save my $10,000 for other fixees and repairs.

bevans6

you really can't get a DD warm idling, so there is no reason to do it.  If you have an external compressor to build air pressure, do that, start it, and drive it away.  With 1200 mpg of oil, you're not too bad yet.

Brian
1980 MCI MC-5C, 8V-71T from a M-110 self propelled howitzer
Allison MT-647
Tatamagouche, Nova Scotia

eddiepotts

That's wise. Now that your here you can get a million dollars worth of info for free. All shops will tell you what they can fix for a little cash. Only someone with a been there done that attitude will tell you if it is worth it. Don't repaint the whole bus because of a scratch on the bumper.

rxeno

One thing that is concerning is the oil leaking apparently soaked the part that is the emergency brake.
How does that fit in with this discussion?
And what to do, oh my :)

Len Silva

The other thing is to be sure you are using the right oil.  Straight 40 wt Rotella-T or Delo-100.  No multi-viscosity oil in these engines.

Hand Made Gifts

Ignorance is only bliss to the ignorant.