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'97 'Shaker with 3406e Shake!

7K views 8 replies 5 participants last post by  Same issues... 
#1 ·
Hello all from Colorado, new guy to the forum here. First of all, thanks to anyone and everyone who takes the time to read my post with my situation, I have spent weeks and weeks searching tirelessly on these forums to find a similar situation to mine with limited luck. I have a 1997 Freightliner with a 5EK 3406e, 475hp, 18 speed trans, Rockwell lockers in the back with 3.91 gears. She’s not much to look at, but this truck is the queen of the job site with those lockers, I do end dump work. Anyway, I’ve owned it for about 6 months, and it’s always had a slight shake at 1200rpm that gets a little worse at 1300, then disappears at 1400 on up.

Having grown up on a farm with all manner of diesel engines, each with their own quirks, I decided that it wasn’t much to worry about. However, it seems like within the last several thousand miles that it has started to be a little worse. I went ahead and took it into Diesel Services of Northern Colorado, and had them replace the vibration damper (original one was still rubber), run the overhead, and check the overall health of the engine while trying to diagnose the shake. The technician did notice the shake, he did bubble test of the coolant, pressure checked my CAC and rest of system after the turbo, hooked up the computer, did cut-out test. Found the overhead to have several tight exhaust valves, and found injector 2 to give what he said was a “weak reading.” Injector wire harness replaced, said injector now reads fine. $1600 shop bill later, truck has more power, runs smoother 1400rpm on up, but still has a shake. Truck now has a pronounced miss when you poke the throttle when it is cold but goes away when warm. Doesn’t miss when you feather the throttle. The funny thing about the shake is, it does it whether you’re on the throttle or coasting foot off the pedal, and whether the clutch is in or out.

No visible blow-by, uses 1 gallon of oil every 9500 miles, I average 6mpg with the truck. I have always thought the power leaves a little to be desired, I am floorboarded even while empty sometimes to maintain my 1550rpm road speed of 68mph when I encounter hills. Doesn’t blow smoke, and the shop says it has the 500 low nox file when they checked the ECM.

Engine was formerly an OTR truck, owner/op for Interstate Distributor. Came from the factory with 24.5” rims and rubber, he had converted to 22.5” to meet a height requirement when he bought the truck new in ’97. Was able to find most receipts for work done over the years from the dealer in Reno where he had the work done, except for the overhaul. Truck has new turbo and exhaust prior to my ownership. Previous owner said the only time the truck had ever left him on the side of the road is when an injector would fail, so over time it’s had 3 new injectors.

The shake seems to me to be something rotational, like an out of balance flywheel or something internally out of balance inside the engine? Coupled of course with likely injector issues? Any suggestions or experience is much, much appreciated! I am also willing to pay if someone can figure this out!
 
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#2 ·
Miss: A lot of trucks have a cold miss?
Vibration: Does it vibrate out of gear? If you push the clutch in, let off the throttle and the vibration continues would that not eliminate the engine? I have seen thousands of dollars spent and the problem solved when a u-joint was replaced. Many possibilities try to diagnose it and quit swapping parts. Start with out of round tires.
Low power: I read if anyone takes a truck like yours to the engine manufacturer they are required to install the low NOX program. You would have to go to an independent programmer to get it returned to original or improved.
 
#3 · (Edited)
Thanks for the reply and your thoughts! It's definitely not a vibration in the sense of what I've always experienced in trucks, I've had u-joints go out before on the other KW's on the farm and that's definitely a vibration, especially when you get up to speed. Checked u-joints, all seem to have no play, trans in neutral. This is definitely a "shake," that corresponds to engine RPM and not driveline, like how a cammed V8 feels when it lopes. So here's the scenario. Taking off in low gear, you feel the engine shake as it gets up to 1400, then goes away from then on as I keep it 14-1600 running through the gears. You get up to speed, slow up a little for traffic, foot off the throttle, coasting, engine goes down to 1300, shake starts. Still at highway speed, you put your foot on the clutch, let the engine go to idle. Engine shakes while it is slowing to idle. You keep your foot on the clutch, rev the engine a few times, and shake is always present 11-1200 to 1400. Let the clutch out, truck has slowed a little, keep it in the same gear, engine still shakes, speed up, shakes till 1400. Brand new tires all around. Virgin rubber Bridgestones from TCI. No tire shake, almost new condition accu-ride rims when I converted back up to 24.5".

As far as the power goes, I have heard that the low nox tune is a dog, but I don't believe this truck should struggle the way it does, even on smaller hills. Our two other trucks, both 5EK's, both '95's, bone stock pull circles around this truck, and it's pretty common for them with live bottoms to gross 100k hauling sugar beets out of the field. I'm usually 80-82k gross depending on how adventurous I'm feeling, what with having to use the interstates as most direct route with my crushed rock I haul. Engine should still build to the rated HP, even though it's slower to get there, right? I'm more concerned with the shake than the power for now. Spoke with Cat, looked up my serial 5EK83742, says it comes with the injectors and iron to easily uprate to 550. Not looking to hot rod and probably won't uprate, but I don't think it should have a problem running with the other trucks. It's a little frustrating!
 
#4 ·
No one's mentioned clutch.

I would take all your bolts that hold your clutch to the flywheel out and rotate the clutch 180 degrees and put bolts back in. You can do this thru the inspection cover on bottom off bell housing while you bar engine over.
Could be a clutch not sitting correctly on the flywheel. Or simply a bad out of balanced assembly.
If its old maybe just put a new one in.
 
#5 ·
Sounds like Swaan flew through that gauntlet before. I thought about an engine vibration caused by clutch springs out of place and another that the mounting bolt shoulders bottomed on the resurfaced flywheel before the pressure plate was tight against it. Those were a long time ago and I do not recall there exact reactions. I did not mention them because I would thank the higher the RPM the greater the vibration. Other out of balance stuff causes vibrations that come and go with speed. Swaan maybe on track with clutch problems at different RPM's.
 
#6 ·
I never thought about the clutch! Thanks swaan and tenwheeler both for your expertise. When I get the truck back tomorrow I will pull the inspection plate and get to work! Come to think of it, the last clutch brake adjustment I had the shop make didn't make any difference with slowing things down to get into gear. Wonder if this is a sign of a clutch problem? Can a flywheel wear unevenly enough to cause a shake as well?
 
#7 ·
I would do as swan said and unbolt the clutch from the flywheel, but I would slide if back as far as possible away from the flywheel and start the truck and rev it to see if the shake is still there. I have been through a similar problem that turned out to be the clutch. Also have had similar problems that were never found.

Check fuel pressure, Check for air in fuel suction and return lines. Has the cam sensor ever been recalibrated in the ECM? It sounds odd, but pull your belts and remove the damper and start the engine. Rev and check for the shake.

If separating the clutch and the above items make no difference, I would get the ECM reflashed with a pre LowNOx file and see how it runs. If it persists, injectors would be my next step.

Good Luck!
Engine shakes can drive you nuts!
 
#8 ·
Okay some updates. Thanks again to everyone willing to chime in on my truck issues here. Took the clutch away from the flywheel, still the shake persists. Took it to the shop, mechanic is convinced it’s the flywheel, unknown if it’s been surfaced or balanced in the past. So, looks like lots of life left in the clutch, so unfortunately I made the decision to live with the shake for now and concentrate on the performance issue. Fuel pressure is 65psi at idle and 75-78 at 1500 Rpm. Mechanic did cutout test, and found that like the other shop, cylinder 2 wasn’t contributing much and apparently neither was cylinder 1.

Sprung for two new injectors from Cat, and after having them installed, noticed a marked improvement in power. Not up to par with our other two 3406E trucks when it comes to lugging power, but all of a sudden, here is my doggy old truck now with the familiar Cat 1400-1600 rpm power band, just like our two KW’s. Ran some loads to Torrington, WY and actually didn’t want to use the cruise, had a lot of fun just using a third of that throttle at 65mph, hearing that turbo spool with every little hill, was almost what I expect the truck to run like in the long haul.

I did notice a new couple of “blips” under full load, seems like maybe the two injectors that were installed might be stronger than the rest. Boost did not change, still would max out at 22 psi, ultimately didn’t gain me any more power on the hills, but at least it would full spool at half throttle now, instead of all the way to the floor. Truck ran like this for 2 weeks, and yesterday after coming back with my last load, I noticed that after pulling out from the pit and onto the interstate that here I was again, back to having to push that throttle almost all the way to the floor to get the turbo up to full spool….. Lost throttle response through every gear, instead of being able to skip gears in low range when starting out, I now was back to hitting every single one, floorboarded with every gear change to get it to accelerate like it did before.

Frustrated is an understatement! Ran it all day like this, it doesn’t miss, just needs the throttle mashed to get to full spool. Before the injector swap, it would average 6.4mpg. After injector swap, I was getting about 5.6, but my enjoyment factor went way up! Checked fuel pressure again today, still 75-78 psi. Now today, after filling up, I’m back to 6.3…… Maybe it’s time to just break down and take it to Cat and put it on the dyno and diagnosed for another 900 bucks….. Maybe time to spring for 4 new injectors.... I don't have Cat ET, is there any other way to check cam sensor calibration like mentioned in the above post?
 
#9 ·
Okay some updates. Thanks again to everyone willing to chime in on my truck issues here. Took the clutch away from the flywheel, still the shake persists. Took it to the shop, mechanic is convinced it’s the flywheel, unknown if it’s been surfaced or balanced in the past. So, looks like lots of life left in the clutch, so unfortunately I made the decision to live with the shake for now and concentrate on the performance issue. Fuel pressure is 65psi at idle and 75-78 at 1500 Rpm. Mechanic did cutout test, and found that like the other shop, cylinder 2 wasn’t contributing much and apparently neither was cylinder 1.

Sprung for two new injectors from Cat, and after having them installed, noticed a marked improvement in power. Not up to par with our other two 3406E trucks when it comes to lugging power, but all of a sudden, here is my doggy old truck now with the familiar Cat 1400-1600 rpm power band, just like our two KW’s. Ran some loads to Torrington, WY and actually didn’t want to use the cruise, had a lot of fun just using a third of that throttle at 65mph, hearing that turbo spool with every little hill, was almost what I expect the truck to run like in the long haul.

I did notice a new couple of “blips” under full load, seems like maybe the two injectors that were installed might be stronger than the rest. Boost did not change, still would max out at 22 psi, ultimately didn’t gain me any more power on the hills, but at least it would full spool at half throttle now, instead of all the way to the floor. Truck ran like this for 2 weeks, and yesterday after coming back with my last load, I noticed that after pulling out from the pit and onto the interstate that here I was again, back to having to push that throttle almost all the way to the floor to get the turbo up to full spool….. Lost throttle response through every gear, instead of being able to skip gears in low range when starting out, I now was back to hitting every single one, floorboarded with every gear change to get it to accelerate like it did before.

Frustrated is an understatement! Ran it all day like this, it doesn’t miss, just needs the throttle mashed to get to full spool. Before the injector swap, it would average 6.4mpg. After injector swap, I was getting about 5.6, but my enjoyment factor went way up! Checked fuel pressure again today, still 75-78 psi. Now today, after filling up, I’m back to 6.3…… Maybe it’s time to just break down and take it to Cat and put it on the dyno and diagnosed for another 900 bucks….. Maybe time to spring for 4 new injectors.... I don't have Cat ET, is there any other way to check cam sensor
DID YOU EVER FIGURE THIS OUT? I NEED HELP! MINE IS DOING THE EXACT SAME THING AND ITS DRIVING ME CRAZY! I HAD A NEW CLUTCH PUT IN AN WAS TOLD THAT A FLYWHEEL DOWEL PIN WAS SMASHED IN. I WONDER IF THE FLYWHEEL HAS ANYTHING TO DO AT TIMES WITH THE SLIGHT POWER VARIATION AND OUT OF BALANCE FEELING?! PLEASE SHED SOME LIGHT ON THIS ISSUE...
 
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