Community Forums

garberz · 02-10-2014, 11:27 AM

Coming home from a trip recently I had to be towed the last 125 mi. The motor started to spit oil out of the crank case breather and dip stick tube. I probably drove it 100 mi. before I noticed this issue. After I got it home and guessing on several theories on what might be going on, I removed the valve cover and discovered that the bridge and pin under the rocker arm had fallen off the exhaust valves on cylinder #3. So the exhaust was being forced past the piston and rings, creating pressure in the crank case. There's no visable damage to any of the valve train components, even the pushrod is straight. I'm hoping that it was because the valves had excessive clearance as to why it came apart. No loss in oil pressure, no overheating. What kind of further damage can I expect? I'm going to adjust the valves, replace all the valve cover bolts (1 broken one), change the oil and filters, and cross my fingers. What are your thoughts?

Mark Davis

Lee0920 · 02-10-2014, 01:53 PM

Doesn't sound like it hurt anything, put her back together, do a full overhead adjustment and fire it up. Adjustment spec's should be on the motor data plate.

Good luck.

Mike Canter · 02-10-2014, 03:32 PM

So how loose is the valve lash on the other valves? Has the motor ever been worked on?

garberz · 02-10-2014, 04:39 PM

The motor has never been opened before. A few of the other valves seem like they have excessive clearance. I haven't taken a feeler gauge to any of them. I'm going to have to buy a Cummins manual to adjust the valves. I can't figure out how to find TDC on the motor.

Mark

walt2137 · 02-10-2014, 05:50 PM

Mark acording to my book the engine should be at least 140 deg and the intake normal 0.012 and exaust normal 0.022, my picture shows a plastic fuel pump drive cover on the front of the engine with TDC just above with a mark for TDC, you should be able to pull it out and it takes a tool to rotate the engine called a barring tool pt #3824591 rotate 360 and check lash on 2e,3i,4e,5i,6i and 6e. Torque the valve cover to 106 inch lb.
If needed i could try and scan this page of my manual if needed tomorrow afternoon.

Mike Canter · 02-10-2014, 05:59 PM

You have to have that barring tool Walt mentioned. I tried it without it and it is too hard. .022 will feel loose but it is not.

walt2137 · 02-10-2014, 06:06 PM

I should have posted the check limits Intake min 0.006 max 0.022
Exhaust min 0.015 to 0.32

garberz · 02-10-2014, 06:15 PM

Quote:

Originally Posted by walt2137

.....If needed i could try and scan this page of my manual if needed tomorrow afternoon.

That would be great. I haven't ordered a manual yet. I've been looking online for info, but no luck. I've only found procedures for the 5.9 B motor.

Mark

dieselbeaver · 02-10-2014, 11:53 PM

You will be hard pressed to slip a feeler gauge under the rocker arms..... This is due to the "elephant foot" at the tip of the rocker arm. It pivots to eliminate the scrubbing friction at that point - which allows such a longer interval on the overhead adjustment. You will basically have to back each one off quite a ways, press on the push tube side of the rocker and knock the bridge back down. Then slide your feeler gauge in and bring the adjustment back down.

But, remember if you are checking your adjustment "feel" and you accidentally pull the feeler gauge out - you will most likely have to start over.. All I do is make sure they all have some movement before I adjust them - what they are at when I do a tune up isn't that important. Meaning I take a mental note of #3 intake was tight and #? was loose..

Don't quote me but the adjustment interval is like 100k after an initial readjust. So basicly it's a once and done in a RV. In a pinch if you can access the alt pulley nut you can usually rotate the engine backwards if you have to.

Have fun

jdecastro · 02-11-2014, 06:40 AM

Also check your camshaft. I know of thrree cam failures in 2000 ISC's, mine included. My cam failed, broke a cam follower ans broke a chunk out of # 4 cylinder insert. When the cam was removed other cam lobes were bad as well. Good luck.

garberz · 02-11-2014, 07:19 AM

Quote:

Originally Posted by jdecastro

Also check your camshaft. I know of thrree cam failures in 2000 ISC's, mine included. My cam failed, broke a cam follower ans broke a chunk out of # 4 cylinder insert. When the cam was removed other cam lobes were bad as well. Good luck.

This is why I have my fingers crossed.

Papa_Jim · 02-11-2014, 09:27 AM

If you find a valve with way too much clearance, it might be a sign that something (like the camshaft lobe) is wearing out.

I would put the valve bridge back together and roughly adjust it. Then I would rotate the engine and visually check how much the valve is opening compared to the other valves. I might even find a way to use a dial indicator on a magnetic base to get a comparative measurement between valves.

If the camshaft is wearing out, putting the engine back together and running it could lead to catastrophic engine failure a little later on.

Jim

garberz · 02-11-2014, 09:55 AM

Quote:

Originally Posted by Papa_Jim

If you find a valve with way too much clearance, it might be a sign that something (like the camshaft lobe) is wearing out.

I would put the valve bridge back together and roughly adjust it. Then I would rotate the engine and visually check how much the valve is opening compared to the other valves. I might even find a way to use a dial indicator on a magnetic base to get a comparative measurement between valves.

If the camshaft is wearing out, putting the engine back together and running it could lead to catastrophic engine failure a little later on.

Jim

I'm doing this right now. The dial indicator is a good idea, thanks for the tip.

Mark

garberz · 02-11-2014, 04:06 PM

Well keeping my fingers crossed just wasn't enough. I put it back together and adjusted all the valves. The adjuster screw on the rocker arm, (for the exhaust valves that the bridge fell off of), is .060 farther into the lock nut, than the rest of the adjusters. So it looks like I lost that amount of material from the cam or lifter or a combo of both. I'm going to do some research and see what's involved with changing the cam and lifters. First thing is, "Will the cam come out of the motor, with the motor still in the coach"? The drive gear will be on it, I'm assuming it needs to be pressed off.

Mark