1987 7.3 IDI thumping through intake and smoking

[Wildbill_81]

I've seen a couple posts with these symptoms but unclear on how some of the sources contribute...Here is my situation:
I bought a 1987 S1600 International with a service body from a local welding shop. He got it back in 2009 from the local power company at auction. The truck is a 7.3 IDI with a 5sp man trans and 2 speed rear. The odometer reads 078,000 miles so I know it has to be 78k since I can't see the truck lasting over a million miles. Anyway, The truck starts and runs but rough. There is also lots of blue/white smoke(enough to think it's on fire) and reeks of fuel bad enough to make your eyes water or **** off the guy behind you. Also it has what sounded like a knock(or bad injector), but when I remove the air cleaner lid it is crazy loud, almost like hitting a block of wood with a hammer. Not very metallic, just like the vacuum pump through a 100 watt amp... I replaced all the injectors with remans and no change in the smoke or noise. Some other threads suggest a valve issue. I could understand a sticking intake valve leading to the thumping sound but could that also cause the smoke? Also I noticed what looks to be about a cup of oil on the lifter valley pan. I got a reasonable deal on the truck thinking(and was told by the owner) that it was a fuel injector issue but now I'm starting to wish I didn't buy that thing. Any suggestions? It's getting cold out here in VA so I want to get this fixed before I'm out there in a parka busting my knuckles.
Thanks for any advice!

 

[whitehorse]

My truck done that and was a bad lifter...but check to see if it thumps through the exhaust...could be a bad valve if that's the case

 

[Wildbill_81]

Thanks! The exhaust does puff out the muffler, but hard to tell any abnormal noise under there, plus the muffler is the size of a trash can...

 

[IDIoit]

a leak down test will tell ya.
but pull the valve covers off and check the rockers,
if there good, pull the intake and check lifters,
if they look ok, youre pulling heads.

 

[riotwarrior]

Welcome.

Where did u get remanned injectors?

Likely not building nuff comp to fire and burn all fuel hence fuel and eyes water issue.

Huff out intake could be guides too..best bet as IDIoit said...check under valve covers...u can run with no cover short term...messy but will work. If nothing appears wonky then intake check lifters..

A busted rocker or some valve issue could cause tbe non burning fuel if no air is getting in thus creating the unburnt fueled exhaust.

Let us knkw what you find...oh

Pictures too

 

[BrandonBerkosky]

Mine did the EXACT same thing. You actually put into words what I could not.

I'm NOT saying go buy a new pump. But I put on a used (known to be good) pump. Timed it. and it went away.

Good luck.

You must be registered for see images attach

 

[Wildbill_81]

Update to the S1600

Mine did the EXACT same thing. You actually put into words what I could not.

I'm NOT saying go buy a new pump. But I put on a used (known to be good) pump. Timed it. and it went away.

Good luck.

You must be registered for see images attach

Well since it's 70 degrees out and the kid opened all his presents, I went out and pulled the valve covers. Everything is in order and extremely clean...started it up to look at the valve train and everything seems to operate as designed. I also took off the oil cap while running and it does smoke out of the filler neck. Next step i guess is swapping the pump, I have a good one on the shelf. Also ordering a compression tester this week....

 

[Wildbill_81]

Update to the S1600

Well since it's 70 degrees out and the kid opened all his presents, I went out and pulled the valve covers. Everything is in order and extremely clean...started it up to look at the valve train and everything seems to operate as designed. I also took off the oil cap while running and it does smoke out of the filler neck. Next step i guess is swapping the pump, I have a good one on the shelf. Also ordering a compression tester this week....

 

[chris142]

Shouldnt an 87 be a 6.9?

 

[icanfixall]

Shouldnt an 87 be a 6.9?

Yes it should be a 6.9 and the best year for it. Also it was the last year for the 6.9. This engine will have the ZD9 glow plugs with the solid state controller.

 

[OLDBULL8]

I bought a 1987 S1600 International with a service body from a local welding shop. He got it back in 2009 from the local power company at auction. The truck is a 7.3 IDI with a 5sp man trans and 2 speed rear. The odometer reads 078,000 miles so I know it has to be 78k since I can't see the truck lasting over a million miles

Things don't add up here. International must of had a 6 digit Odometer, Ford only had a 5 digit Odometer in 87, but he says 078000, must be a 6 digit or the cluster has been changed. A Power Co. would have a lot of idle time on the engine. They never shut them off except to eat lunch and end of shift.

In 87 the engine should be a 6.9L, not the 7.3L. Check the pad on the drivers side in the front next to the IP gear tower. Do the numbers start with 6.9L or 7.3L? That would tell us if the engine has been replaced at some time.

EDITED:

In 1987, to reflect the corporate change from International Harvester to Navistar International, the S-Series received new badging. The IHC logo seen on the steering wheel was replaced by the Navistar diamond logo. On the outside, the International name was moved from the top to the bottom of the grille. Instead of matching the grille color, all S-Series trucks wore a red International badge.

IDI420 170 hp (130 kW)@3300 D V8 420 cu in (6.9 L) 1983-87

IDI444 D V8 440 cu in (7.2 L) 1986-89

DT466 210 hp (160 kW) D I6 466 cu in (7.6 L) 1979-89

 

[Hydro-idi]

Yes it should be a 6.9 and the best year for it. Also it was the last year for the 6.9. This engine will have the ZD9 glow plugs with the solid state controller.

The 87 6.9 idi's also have the updated 7.3 style rocker arms.

 

[OLDBULL8]

Should have added, can't tell by the stickers on the valve covers if any are on there yet, they could have been changed.

 

[Sorro71]

I have a November 87 and it came from the factory as a 7.3IDI.
Not sure about the International's though.

 

[chris142]

I have a November 87 and it came from the factory as a 7.3IDI.
Not sure about the International's though.

Your new model year starts in september.yours being november is an 88