Delivery valve internal leak as a cause of nailing? Yes? No? Maybe??? - Page 14 - PeachParts Mercedes-Benz Forum

Diseasel300 · #**196** 12-02-2017, 12:23 PM

Quote:

Originally Posted by funola

Can a burned exhaust valve cause nailing sounds? Somehow I think it can.

I'd sure think it would. Low compression is often attributed to nailing and a burnt exhaust valve would certainly cause low compression...

phlfly · #**197** 12-02-2017, 09:13 PM

So you think oily intake manifold is turbo blowing oil? interesting. I thought turbo oil cooling/lubrications is closed loop.

Another to look for nailing noise is timing chain. My friend owns a shop he was all his life on automotive repair (40+ years), worked back in days at Mercedes dealer, he told me the chain can effect nailing too. I might doing this too, after done with fuel delivery valve. I'm planning to jump on DV in mid - December, I will be on vacation so I would have plenty of time, plus I will replace all glow plug as well as intake will be off any way.

Also I did more diesel purge, until it would do fuel color only. Results is even better.

https://youtu.be/gA5dgXhYQ-Y

Quote:

Originally Posted by Diseasel300

The ALDA works off of the intake manifold pressure. It has no connection to the fuel system other than operating a lever inside the injection pump.

Air in the fuel system will come from leaks, old hoses, or loose clamps. The hard lines under the car are also known to develop pinholes from rust. Be looking mainly on the suction side of the lift pump for air ingress.

Why do you need an oil separator? There's a baffle built into the valve cover that does a pretty good job of separating oil, even if the PCV valve has given up the ghost like mine has. If you're blowing oil out the valve cover, you need to address why, the 603 is a relatively low blow-by engine. Excessive oil in the intake manifold is likely from the turbocharger.

Diseasel300 · #**198** 12-02-2017, 09:47 PM

The turbo is fed oil by the engine lubrication system. It has seals internally to prevent the oil leaking out. Over time, they wear out and you start to get oil leaking past the seals on the compressor and/or turbine side. The result is oil consumption, but not by the engine in the usual sense. Leaks on the compressor side will foul the intake manifold and make the engine burn oil. Leaks on the turbine side can result in burnt oil or if bad enough, oil dripping out the tailpipe.

The fact that diesel purge is helping your engine tells you that you have compounded issues. Dirty IP, dirty injectors, and probably built up carbon in the prechambers. Go give it a good hard thrashing on the road for an hour or two and see if it improves. Should be enough time to burn some of the carbon and coke out of the prechambers and head. You'd be surprised what a good ol' "Italian Tuneup" can do for these old IDI engines.

phlfly · #**199** 12-02-2017, 09:58 PM

I replaced nozzles not long ago. But removed injectors were all tested for the pressure and none of them even close to 2000 psi. Number one was really bad it was pissing fuel not even spraying .

Diseasel300 · #**200** 12-02-2017, 10:04 PM

Pressure is only part of the picture. Spray pattern and "chatter" are far more important than the actual pop pressure. A poor spray pattern or a pintle hanging up and piddling will cause nailing, even if the pop pressure is a perfect 135bar.

phlfly · #**201** 12-02-2017, 10:08 PM

Did you watch my last video? I think it's running very good compare to my first video, don't you think?

Quote:

Originally Posted by Diseasel300

Pressure is only part of the picture. Spray pattern and "chatter" are far more important than the actual pop pressure. A poor spray pattern or a pintle hanging up and piddling will cause nailing, even if the pop pressure is a perfect 135bar.

OM617YOTA · #**202** 12-02-2017, 10:35 PM

Could the turbo dumping oil into the intake cause nailing too? As far as the engine's concerned, it's just untimed fuel delivery............

phlfly · #**203** 12-03-2017, 08:00 AM

Untimed fuel delivery ??? Can you explain how you are thinking this way?

Quote:

Originally Posted by OM617YOTA

Could the turbo dumping oil into the intake cause nailing too? As far as the engine's concerned, it's just untimed fuel delivery............

OM617YOTA · #**204** 12-03-2017, 09:02 AM

The injection pump delivers fuel at a very specific time in the engine's cycle. Engine oil going into the intake and being sucked into the cylinders will burn just like diesel. With that delivery method, it's in the cylinder all along and will combust as soon as the temperature in the cylinder is raised by compression, instead of when the injection pump controls injection.

Diseasel300 · #**205** 12-03-2017, 09:53 AM

Unless you're slobbering a huge amount of oil, I wouldn't expect the turbo blowing oil to cause nailing. If you had enough oil blown in the cylinder to actually combust on its own, I'd be far more worried about an uncontrolled runaway condition, not to mention the Chernobyl cloud belching out the back of the vehicle.

Phlfly - Your engine does seem to have benefitted from the diesel purge treatment. There's still a hint of nailing, but it doesn't sound like an iron-worker's shop anymore. Before shelling out $300 on new DV parts, I'd be pulling the ones you have and inspecting them for trash on the seating faces. If they aren't all pitted and torn up, the cerium-oxide cleanup seems to work well.

phlfly · #**206** 12-03-2017, 12:35 PM

It's true but already ordered valves. I will do close inspection and will try post the condition them soon get them out of pump.
But it's more like mid-Dec.

phlfly · #**207** 12-11-2017, 09:31 PM

Got all goodies:
Delivery valve (two parts, one is "piston" and second round like thick washer)
DV seals, washers and springs
DV socket
Glow plug set
Glow plug reamer from Mercedes source (looks like drill)\
Intake gasket.
I would try to attack it this week. I will clean intake as well, I found Machine shop they will clean it for me

Btw what is size of the hex bolts for the intake? Strange tried all mine hex and some too big, some little loose.

Father Of Giants · #**208** 12-11-2017, 09:43 PM

Quote:

Originally Posted by phlfly

Got all goodies:
Delivery valve (two parts, one is "piston" and second round like thick washer)
DV seals, washers and springs
DV socket
Glow plug set
Glow plug reamer from Mercedes source (looks like drill)\
Intake gasket.
I would try to attack it this week. I will clean intake as well, I found Machine shop they will clean it for me

Btw what is size of the hex bolts for the intake? Strange tried all mine hex and some too big, some little loose.

I forgot, but you will need a ball end hex bit or hex key, I STRONGLY recommend you get a long, ball end, hex bit, and a ratchet with a very high tooth count. You may also need a universal joint as well. When I took my intake manifold off the gasket was destroyed in the process, so I advise to buy one ahead of time.

I removed mine with a hex key and it wasn't fun at all, it will be frustrating putting it back on and the experience will be very uncomfortable.

Diseasel300 · #**209** 12-11-2017, 10:11 PM

Do you actually have any dead glow plugs? If not, leave the manifold in place. As FoG said above, the manifold is a SERIOUS pain. It wouldn't have killed them to make the bolts accessible, but nooooooooo, that would be way too easy! Saddle up for lots of swearing and walking-away sessions if you have to pull the manifold.

Father Of Giants · #**210** 12-11-2017, 10:42 PM

Also if you do pull the intake, make sure you buy all of the rubber and plastic pieces that attach to the injector hard lines, because once they come off you will not be able to reattach them, they'll be far to old, hard, and brittle.

Even when brand new, the injector hardline rubber and plastic bits are nearly impossible to put on, very difficult.