JoeH

Thinking about it more, I'm going to go out on a limb and say Fuel Filters are possible.  My E7 did that, sounded almost like the Jake brake was coming on above 1500 rpm under load, and didn't quite have as much boost as it should as it neared the governor.  Took 2 sets of fuel filters to clear it up, hasn't done it since.

When a cam lobe gets wiped it gets worn to nothing fast. Check for bent pushrod, driver could have over revved the engine and floated the valves a bit.

Before you pull expensive parts, pull the valve covers and see which rocker has too much slop. More often than not, you'll find either one of the engine brake valve plates popped out from a weak valve spring or a bent pushrod, or worn cam lobe.  We have had all 3. If it's the engine brake valve plate missing on an exhaust valve then just delete the engine brake.

I'd be surprised if they are the same, but then again the oil pans use the same gasket.... Get VIN numbers from an E6 truck and an E7 truck, ask your dealer for the part number for each timing cover gasket.  Same for the front main seal.  The E7 can run the steering pump on the front of the timing cover, so I'm sure the covers are different.

I'd just sift through a Mack junk yard and find a donor front engine mount.  Don't know where you live, but Coopersburg PA has a good one at the Kenworth dealership.

Also make sure those 2 little pins in the side where it says "TOP" are mounted top, they're air bleeders so you don't get a pocket of air against the thermostat when you refill the system. Air won't conduct heat to open the thermostat properly on the first heat cycle.

Automotive thermostats frequently don't have those so I drill a pin hole in them to serve the same purpose.

Should be running at 180, that's where all my Macks run, 1979-1995. Dont know what your truck setup is, if it's real light and you have no hills it'll take forever to warm up, it's meant to work hard.  A new thermostat would have been a good idea, they're not expensive.  Running cold slobbers up the valves, can make them sticky.

Not sure how to add photos at the moment, but we found the oil leaks!  There are 10 holes in the oil pan flange presumably for spot welds to hold the reinforcing strip in place.  Well, someone never spot welded it, so oil was able to seep past the gasket at the front and rear.  

$2,000 for a part 90% complete.

I've had fuel filters cause this; replaced them twice a few days apart and it cleared up.  Almost sounded like Jake brake kicking on lightly. Fully mechanical  '95 E7-350.

I'd never heard of 2 piece pistons until I looked up E7 rebuild kits.  What is the advantage of 2 piece pistons vs 1 piece pistons?

Does anyone know if the oil pan  threaded bosses in the timing cover and flywheel housing are open to the crankcase or if they're sealed?

It's looking like the oil pan gasket doesn't seal around the 2 bolts front and 2 bolts rear. Pressurizing it made oil pour out of the front around the oil pan reinforcement straps, where it wasn't leaking before. Didn't make it leak at the rear much, but we're going to pull the pan back off, smear some RTV silicone on it all around and see what happens!

Did you set the heads down on a table and smash the injector tips while you had the heads off?

Have you driven a manual trans before? Are you "popping" the clutch or easing it out slowly?

I think we're missing some more details. We don't have acknowledgement that hes releasing the parking brake.  When did the truck roll last? Has it been sitting for a long time? What work did you have to do on it?

Sidenote, the part number on my '95 E7 oil pan gasket is the same as my '79 ENDT676.  Mack really liked to keep things standard.  I'll bet one of the oil pans from my 3 spare engines would have fit just fine, and saved me $2,000.  But my daily driver gets what my daily driver needs, no screwing around to save a buck.

'95 rd688s with an E7-350.  Horrible oil leak at the rear of the oil pan area, found 2 cracks in the old oil pan so we put a new one on; still leaking. Inside of the flywheel housing is dry.  Book indicates there's an "isolated" and "non-isolated" oil pan setup.  Do they use the same oil pan?  Mine is the non-isolated setup, did the dealership give me the wrong oil pan? Hoping it's not related to the flywheel housing "Silastic" seal to the engine block...

Could a flywheel housing-to-block bolt break or loosen and allow enough flex to crack the old oil pan and cause the new one to leak?  21,200+ hours.

Any common problems in that area?

The em6-300L is governed at like 1750 rpms. It won't do 2100 rpms unless you're going down hill. We bought an 88 2 years ago, still assembling a truck body for it so we haven't had it on the road yet to know how it drives.

And it'll get colder again.

10 hours ago, doubleclutchinweasel said:

What the...?

Lowrider.

atmospheric-phenomenon-44.bin

Don't think it does, I think it's coronavirus facebook videos she shows me.  Last one she showed me was a mom getting in trouble for not wearing a mask while holding a sign?  But people here are starting to get arrested in more liberal states for not wearing masks.  

We aren't compelled to vote by the government because we established our government. It's ours to participate in or not.  My wife keeps showing me videos of people getting arrested in Australia for protesting the government.  What worth would a right to protest be if you can only protest what the government allows?  That isn't protest.  Here, we can protest the government to our hearts content with no fear of arrest, so long as we respect the rights of others. (I.e. not causing property or bodily harm to others)

America has 50 states, not 51.  If you don't want to vote for trump or Biden you can write in whoever you want.  Mickey Mouse gets a vote or two frequently.  Politics is a dirty business of power hungry people trying to retain their seat so they can personally gain via loopholes.

The critical difference between America and every other government in the world: our government is established BY the people.  The people give the government their authority.  No king or queen, no communist dictator.  Our right to own guns is the last line of defence we have against tyranny.