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Newbie with black smoke

5K views 33 replies 8 participants last post by  Wik837 
#1 ·
I have a 97, I changed the lower intake gaskets last night I found that the old gaskets had a metal blocker over the egr port. Now since I changed them I'm getting a ton of black smoke at 3/4 or more throttle that won't go away, any ideas?
 
#2 ·
The most common reason for Black smoke is low boost. Doublecheck everything that you disturbed while doing the job, including vacuum lines, and anything pre-and post turbo that you may have disturbed.

If your vacuum system is still all original, the factory lines are notorious for becoming brittle and cracking, especially after they are disturbed by the sort of work that you performed. If you cracked a line or something is loose, the wastegate could be unable to properly close, which would result in low boost, which would explain the smoke.
 
#4 ·
Well checked everything and it looks good the only thing I see that maybe suspect is if I put the waste gate all the way up it will snap back down half way and slowly lower the rest of the way down, is this normal?
 
#5 ·
With the truck shut off it should be loose and gravitate towards where gravity takes it.

When the truck is running at idle the wastegate should be pulled firmly closed - if you have someone start the truck while you watch it ensure that it does this. Once it's been running for a few seconds you should NOT be able to push the wastegate open by hand while the truck idles - if you can, something, somewhere, is wrong.
 
#6 ·
No truck info in your sig makes it hard to diagnose. Do you have a VIN S (EGR) or VIN F (no EGR) engine? If you replaced the lower intake gaskets for a VIN F with the gaskets for a VIN S... that's the problem. ~FH
 
#7 ·
It's an s (vin) I believe it had f( vin) on them before I changed them. Can not move the wastegate after the truck is running. I'm gonna check to make sure it moves when the truck is started. Ty every one for the help and I will get the sig updated
 
#8 · (Edited)
The wastegate is NOT supposed to move with the truck running. The vacuum pump and WG solenoid is holding it closed like it should. The smoking problem is most likely a non-working EGR system. The previous owner apparently blocked off the manifold returns on purpose to eliminate it. Unless you put F VIN gaskets back on you'll have to restore the EGR system to operation or remove the EGR valve and block off the EGR port in the upper intake. ~FH
 
#9 ·
If it has an egr port, then it is an s vin.

If you remove the blocker, you have to add the egr equipment back in there which I suspect was removed when they block it which is 2 EGR solenoid and a vacuum line. Otherwise, you will have black smoke. So, you may want to block them again and see if the smoke goes away.
 
#10 ·
So just wondering why would you want to unblock the EGR if its already blocked? I believe blocking it increases fuel mileage? correct me if im wrong.
 
#11 ·
I got the truck the truck from a friend of mine that put the egr system back on it but could never get it working right ( I know why now), it was puffing black smoke from 3/4 to full throttle. I was in a pinch and got the truck first thing I did was cut the cat off and it was plugged just about solid. After driving it a week or two the smoke cleared up.the check engine light has been on in the truck since he owned it so I was redoing the gaskets to see if I could clear up the ses light and here I am
 
#17 ·
...After driving it a week or two the smoke cleared up.the check engine light has been on in the truck since he owned it so I was redoing the gaskets to see if I could clear up the ses light and here I am
The SES light ON means there's an active DTC stored in the computer. Did you take it anywhere to have the code(s) read? That would be instrumental in diagnosing the problem and much cheaper than just changing things to see what happens.

Just throwing this out there... somebody purposely replaced the manifold gaskets from VIN S to VIN F to block off the EGR system for a reason. You say your friend "put the EGR system back on it". Did he actually get new EGR solenoids, vacuum lines, EGR valve and MAP sensor or did he just re-connect what was already there? That's important to know because now you have the proper VIN S gaskets and a problem with black smoke.

If he just re-connected the existing EGR system my GUESS would be the EGR valve is bad or stuck. It's a pricey little dude and the cheapest way around having to buy a new one or do the EGR valve block-off mod is just cap off the EGR valve vacuum port and replace the gaskets with a VIN F set. But that's just a possible scenario running through my mind based upon the result of your gasket change and without knowing what DTC is on the computer. ~FH
 
#12 ·
So...stepping back to the boost issue - do you have a boost gauge installed?

I think confirming if you have proper boost levels would be the next diagnostic thing to do. Again, if it was smoking before you did the job, and smoking after..something, somewhere is still wrong, and I keep coming back to lack of boost in my head.
 
#14 ·
There are a few things that can make the turbo unable to build proper boost levels, even if the wastegate system is working properly...but it could be a frustrating wild goose chase trying to narrow down the problem until you confirm you actually have one.

If you find out that you have proper boost then we need to concentrate elsewhere, but if you hookup a boost gauge and find out that at WOT you're only making a few PSI, you've found your problem - the next key is finding out WHERE the boost is going, or why it's not building.
 
#18 ·
#19 ·
I have a scanner, it's always had p101 p400 and p1406. So when I changed the gaskets and saw they had the blockers on the old ones I cleared the codes and am currently waiting patiently for the light to come back on. Also I just cracked the line going to the wastegate to the solenoid rechecking all the vac lines how do I replace this?
 
#22 ·
Also I just cracked the line going to the wastegate to the solenoid rechecking all the vac lines how do I replace this?
The factory plastic lines are known to get brittle over the years - most people just tear them all out and replace them with regular old inexpensive vacuum line from your nearest autoparts place.
 
#20 ·
Also it was reconnected before he got it it's got new vacuum pump new egr and I replaced one of the egr solenoids because the code popped for it, I just don't know if the vacuum lines to the solenoids are routed correctly cause in the book I have compared to how it's routed in the truck it's backwards at the wastegate solenoid if that matters
 
#24 ·
#25 ·
Well the ses light came on today with a1191 code x2 so now it's hunt down where the leak is, and tips. And is there any way if possible to plug the hole where the black tube comes of the air duck and runs in front of the engine bay? I believe it's for expansion air or some thing for the turbo but I see many of the 6.5s with out them
 
#30 ·
I switched the vac lines the way they where routed originally and now no smoke and no codes. Now that I got that all figured out I'm thinking of redeleting the egr. Thank you all so much for your help. The truck is running like a champ now, and I went from 380 miles to a full tank to 250 miles and I'm not even to 3/4s of a tank
 
#31 · (Edited)
Keep an eye on that fuel gauge. It may start to drop dramatically. It's a 34 gallon tank and not all of that is usable. And I can pretty much assure you that truck is not getting 30 MPG (250/8.5). 18-22 highway MPG is closer to the norm with an empty 1500 running a 3.73 rear.

Rule-of-thumb with a diesel is never let it go below 1/4 tank on the gauge. My personal ROT is to never go beyond 375 miles on the odometer without taking on more fuel. Individual MPG and preferences may vary. But I'd put about 1000 miles worth of calculated-at-the-pump fuel consumption through it to compare what the gauge displays at different levels with actual engine consumption before putting on my party dress. And even then, settle on a miles driven refueling figure rather than what the fuel gauge might indicate. ~FH
 
#32 ·
No, I know I'm not getting 30 mpg eaither it was just good to see it stay there so long.thanks for the tips horseman, I'll keep them in mind as I'm going to keep track of my mpg for a base line.
 
#33 ·
My fuel guage tracks pretty accurately from full to 3/4, seems to "hang" for a bit and then hits half rapidly, then seems to hang for a bit before tracking accurately again down to empty.

It's so predictable that I've become accustomed to it, but I too got overly optimistic on what I *thought* was getting for fuel economy on occasion. ;)

It definately sounds like you're doing better though. Getting the boost back to proper levels means your engine is burning it's fuel efficiently again, which of course means you'll burn less of it for the same amount of driving.
 
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