The ol gal is billowing smoke... Help

[LindstheMarine]

I am a total noob. I appreciate your patience and help.

I cant catch a break yall... I just bought my first diesel ever (94 f250 7.3 idi turbo) and have been going through it. After owing it for two days I discovered I need to replace the radiator. I got that done, and whilst taking her on a victory lap the accelorator cable broke. Tonight I got a new cable in there and rescued her from the side of the highway. As I slowed down off the highway and got into town I noticed she was billowing smoke from under the hood. Specifically the smoke was white and it appeared to be comming from where the turbo and intake meet. Also, oil pressure was very low.

I came to realize that I unpluged a part to the fuel filter to get the intake in easier and didnt plug it back in for the ride home (see pic for reference). I am not sure of its name or function. I have a service manual comming in the mail and will get spun up on names and finctions of this kinda stuff soon, so bare with me.

Would unplugging this and driving with it unatached be the issue?

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[The_Josh_Bear]

White smoke fuel smell or white smoke coolant/sweet smell?

And that's just a sensor wire, it'll drive forever with zero sensors hooked up so they will not affect the engine. If you have an automatic there are a few needed sensors for the shifting.

FWIW that wire should trigger the fuel vacuum light on the dash, which is supposed to tell you when your fuel supply pump is toast and your IP is drawing its own fuel. I doubt if most of ours work anymore but at least some do!

Welcome to OBN!

 

[LindstheMarine]

The smell was fuel like with a hint of burn rubber or plastic

 

[LindstheMarine]

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Here is a quick video of the plume

 

[chillman88]

Honestly that looks excessive, but it also looks like regular crankcase "blowby" which is not necessarily anything to be broken hearted over.

At the back of the intake manifold there is the oil drain for the turbo. Look closely around that area and see if the rubber piece it goes into is damaged.

Also check that small 1 inch hose that goes into the air cleaner just before the turbo to see if it's loose or damaged. It goes over to the tuna can looking thing on the passenger side valve cover.

I might even pull that hose off the air cleaner and cap the hole in the air cleaner (do NOT plug the hose) and see if your smoke is still coming from the same spot or not. That hose will smoke like that so you'll want to point it away from the intake while you're trying it.

If you're lucky, you just bumped that hose loose while changing the throttle cable.

 

[LindstheMarine]

Honestly that looks excessive, but it also looks like regular crankcase "blowby" which is not necessarily anything to be broken hearted over.

At the back of the intake manifold there is the oil drain for the turbo. Look closely around that area and see if the rubber piece it goes into is damaged.

Also check that small 1 inch hose that goes into the air cleaner just before the turbo to see if it's loose or damaged. It goes over to the tuna can looking thing on the passenger side valve cover.

I might even pull that hose off the air cleaner and cap the hole in the air cleaner (do NOT plug the hose) and see if your smoke is still coming from the same spot or not. That hose will smoke like that so you'll want to point it away from the intake while you're trying it.

If you're lucky, you just bumped that hose loose while changing the throttle cable.

You were correct! The hose was just knocked loose. You have me worried with the word 'excessive' blowby though. Quite a lot comes out of the oil filler valve and it does sprinkle oil on ya when the cap is off, but it doesnt fill overly pressurized (I'll add a vid if you are interested). Would you consider this excessive for a vehicle with 190k miles that has been sitting for the last two years? Would the large amout of blow by be caused by the truck sitting so long and being generally gunked up? Its probably important to note that I did just change the CDR valve.

I also have a second question that may be related. Last night with the intake off I noticed maybe a tablespoon worth of oil pooling at the opening of the turbo intake. Could this be caused by blowby condensing there? Or perhaps excessive crankcase pressure comming in from the exhaust side blowing oil in?

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[LindstheMarine]

White smoke fuel smell or white smoke coolant/sweet smell?

And that's just a sensor wire, it'll drive forever with zero sensors hooked up so they will not affect the engine. If you have an automatic there are a few needed sensors for the shifting.

FWIW that wire should trigger the fuel vacuum light on the dash, which is supposed to tell you when your fuel supply pump is toast and your IP is drawing its own fuel. I doubt if most of ours work anymore but at least some do!

Welcome to OBN!

I appreciate the help! It feels good to have people willing to share their knowledge with me.

 

[chillman88]

It looks a lot like both of mine do when it's just the cap off. I think it just looked worse because of how it was blowing across the intake.

Mine pools oil there too, yes it's the oil condensing. I actually put a catch can in to help reduce the oil fed into the intake.

I wouldn't lose sleep over it. Yes it's annoying, but it's not a sign of impending doom either

 

[LindstheMarine]

It looks a lot like both of mine do when it's just the cap off. I think it just looked worse because of how it was blowing across the intake.

Mine pools oil there too, yes it's the oil condensing. I actually put a catch can in to help reduce the oil fed into the intake.

I wouldn't lose sleep over it. Yes it's annoying, but it's not a sign of impending doom either

Thanks man! I Appreciate it

 

[The_Josh_Bear]

Yep @chillhas you set pretty straight here. He knows his stuff!
Good call on the blow-by tube, been so long since I had a stock intake I forgot about it!

Along the blow-by lines, these engines have a ton from the factory. I've never heard a good reason why, just really loose ring gaps to start with per the International Harvester spec and so even after a fresh rebuild they have a lot. Point is, it's major engine surgery to change and isn't anything to worry about!

 

[asmith]

Since you mentioned the truck sitting for awhile, it may help cut the blowby down a little by just taking the truck out and driving it hard. these engines love to work, so hook some weight up to it and go drive up and down some hills. obviously you dont want to over heat the engine or get the egts up too high but giving it a good workout can really help clean out these motors and help them run better.
I would also add some fuel additive, such as optilube or hotshots secret both of those have always helped my truck run smoother.
but as the other two mentioned these trucks just have a ton of blowby vs other vehicles. you are never going to get rid of it without changing rings to gapless ones.

 

[LindstheMarine]

Right on! I just picked up a bottle of hotshots and I'll give her a good workout this weekend.

 

[420Bullnose]

Next time you got your truck running, pop the hood and undo the oil cap when she's running, then Rev up the motor (~2000RPM) using the linkage at the IP.

If the "Blow-by" clears up/disappears when the motor is revved up you're good to go, but if continues to smoke at the same rate or Greater, I'd look in to it.

420Bullnose

 

[TexasTruck]

Valvoline restore treatment may also help.