1986 300SDL Shake, Rattle, and......miss? - Page 2 - PeachParts Mercedes-Benz Forum

Diseasel300 · #16 06-04-2016, 11:56 AM

I elected to go by the "Tang" timing method. Ordered the holding tool last night. When it, the O-ring, and the delivery valve seals show up, I'm going to pull the IP and time it from scratch.

I'll post back with a progress report, may be a week or so depending on how long that tool takes to get here.

funola · #17 06-04-2016, 12:33 PM

Have you verified no air at any time in the return to tank line? It's so easy to do it'd be a shame to skip it.

Diseasel300 · #18 06-04-2016, 12:39 PM

I haven't done the air check yet, but it will get done when I get the IP timed and reinstalled. Since I know the timing of the IP is way off now, my main priority is to get the timing right first, then check the quality of fuel flow.

Once the IP is timed properly, I'm still going to check LP delivery pressure and check for air in the return line.

Right now we have 2 confirmations about the fuel system on this car: IP timing is FUBAR, and the LP has a leaking non-return valve (leaks down slowly). The non-return valve may just be gummy (it did sit for nearly 10 years), if the rest of the system checks out after the timing is corrected, I won't lose much sleep over it.

barry12345 · #19 06-04-2016, 04:02 PM

Really glad to hear the initial injection pump timing appears really off. Just a double check though.

You quoted you pulled the valve cover pan. When the cam marks where pretty close as you went for the pump timing on the harmonic balancer. That was when you observed the tang was not present?

I just want to make sure I do not encourage you to go on wild goose chases. I think it was right that you wrote that you also ordered delivery valve seals.

If they are not leaky or problematic as some tests may soon reveal. I would leave them alone for now.. Some people have gotten in a bit of a mess before by changing them .

I am mentally working on an in place delivery valves test anyways right now. I just have not totally formulated it yet. Basically a leak down test by applying pressure either right at the pump or through an old hard line attached to the element. Then basically just rotating the engine slowly until you are sure the element port opening has been slowly passed.

I want to simplify it more and am well on the way to that as well. Thanks to another member mentioning something strange to me as usual got my crazy mind engaged. His friend changed the delivery springs and the engine got noisier was reported. So he put the old weaker springs back in and the noise went away. I suspect the new delivery valve springs advanced the timing to what the manufacturer wanted. Or made it more consistant with the intended factory indicator in your injection pump. There are several possibilities. I actually can visualize this.

Basically why does the manufacturer want the relief valve springs changed when their pumps are rebuilt? The delivery valves seal is done by the residual pressure in the hard line. Yet there is a period where an equilibrium pressure remaining in the element and hard line exist is established before that. Weak springs could delay closing during that period. The effects should be easy to rationalize. Also it is pretty obvious to me that questionable issues in say some delivery valves and not others on the same injection pump will impact the sequential timing somewhat. Upsetting the power balance a little.

These springs could be more important that I initially thought. I do not think most members including myself had though of checking the delivery valves function should be a consideration on a fuel system tune up. This includes the springs. Weak delivery valve springs alone might retard the pumps timing in relation to either the drip method or the 603 fixtures timing position. When the engine is in dynamic service. If they are really cheap is also a consideration.

I may be out to lunch as well in this area but if you are going to see the performance I remember when the 603s were new there are a lot of checks. Most are far more labor intensive than actually buying parts.

If you changed the delivery seals early it might cloud the waters. They are a part that I consider as change by indicative need usually rather than preventative in nature.

You seem to be doing really well so far.

If you can get a helper I would want to roll that engine over until the injection pump timing indicator is visable. Then approximate the damper degrees. I am interested in what the the last owner was up to and would not want to miss anything. At the same time there is not an expectation to do things my way.

It is much like in my youth asking a young lady to do it my way. When asked how that was I said on credit. So my way obviously does not always work out.

At 360degrees out I would expect someone put a timing chain on or perhaps changed the injection pump. I just am cautious by nature if someone else has been at something else as well but doubt it. Again this should be a very strong engine by the time everything is checked out. It is nice when a car does not have to be back on the road as fast as humanly possible as well.

Well I am off to the cottage after a pathetic all day meeting.

Diseasel300 · #20 06-04-2016, 04:22 PM

When I had the head off, I checked that the timing mark on the crank was at 0 (it was). The mark on the camshaft lines up very closely with the mark on the bearing tower with the crank at 0, nearly perfect with the crank around 1˚. The chain and sprockets look in good shape and obviously has very little stretch.

I pulled the valve cover pan to make sure I really was on TDC before I poled it over to check timing on the IP. Tang not present in the inspection/timing port.

I ordered the delivery valve seals to have them on hand in case it's determined they need changed. I ordered a new O-ring seal for the IP to block and had to justify the cost of the shipping, so in went the seals and a couple of other spare parts that were cheap. No point in wasting a freight cost right?

My guess as to what happened in the past with this car is as good as anyone's. I would imagine the IP has been off at some point and retimed only using the crank pulley. Who knows? At this point in time, I really don't care, I just want the engine timed correctly, and that's exactly what's going to happen when my timing lock tool and O-ring get here.

I may try to find the timing tang before I pull the IP and I may not, depends on how I feel that day and if my helper wants to spend the time on it considering that's going to involve a couple more engine spins to realign for proper timing. I don't know what was done to it in the past, and it isn't really important, it's getting corrected now! Do it right the first time and all...

funola · #21 06-04-2016, 05:46 PM

Quote:

Originally Posted by jt20

Begin by spinning the crank until you find the tang. then check the camshaft location. compare with the crank readout.

........

X2.

I'd add that you must have a helper looking for the tang with a mirror (or solo with a USB endoscope viewing the tang on a smartphone) while you turn the crank with a ratchet (with a long pipe for leverage/ fine control). The window is so small the tang flies by real quick. Get the tang in the middle of the window then read the timing marks on the balancer. If you do not see the tang the first 180 degrees of crank turn, go another 180 till tang shows up and read the balancer marks again. Make sure the both cam lobes of #1 are pointing up i.e. cyl at TDC with tang in middle of window.

Diseasel300 · #22 06-06-2016, 10:42 AM

Found the tang.

Had some extra time (more like I made some time) this morning to pole the engine over and search for the allusive tang.

Found it. Centered in window 28˚ ATDC on Exhaust stroke (exhaust cam opening on #1).

I have no idea how the timing got where it is, but clearly someone didn't know what they were doing when they did it.

I'm absolutely amazed the engine was even running. It should (hopefully) run pretty good once the timing is where it should be.

Diseasel300 · #23 06-27-2016, 06:45 PM

It's been a while since work progressed on this car, so I figured I'd post a status report.

This past weekend, pulled the IP and retimed to 15˚ ATDC on the crank timing marks. While the IP was out, replaced delivery valve seals, O-rings, and springs (new springs are noticeably firmer than the originals).

Everything inside the IP was very clean. No rust, no scoring visible on anything (didn't pull the delivery elements out of the body to look at them, but the chambers they sit in were spotless), and no dirt or sludge, however the relief valve rattled and when blown into had absolutely 0 resistance to even the lightest breath. Considering it's supposed to be a "pressure relief" I assume it should have some sort of resistance, then open at some specified pressure. Mine is of the non-serviceable type, so in the bin it went and I've ordered a new one from Pelican.

A bit of reading on this thread: Fuel injection pump starvation with a good lift pump

and elsewhere on the 'net pretty well convinced me to part with the money to replace the relief valve with a known-good one, especially considering the hideous idle my car has (hopefully had!).

While I have the radiator and vacuum pump out, I decided to replace the vacuum pump since it's already out and the one in my car is original (stamped lid, non-caged bearings) with 173K on the clock. Reading horror stories about how these grenade and kill the engine, I figure it's worth my time to replace it! The face cam on the timing device is in good shape and free from scoring and the roller on the vacuum pump was in good condition too, so it's been lucky this long in life, I just don't feel like relying on luck for something that can potentially cause that much damage. Knowing my luck, it would run out on the maiden drive!

So now the timing is correct, the delivery valves are rebuilt, another problem area identified and corrected (pressure relief), and parts on order to get it done. Once everything is back in, I'll be back with fuel pressures and a report on whether or not it runs any better.

jt20 · #24 06-27-2016, 07:07 PM

sounds like you are being very conscientious and picking up important maintenance items early.

I am only mentioning this next item because of the efforts you have mentioned and your care for detail thus far.

the tesnioning system for the serpentine accessory belt wears out and could cause failure for the front timing cover if not well maintained.

Inspect the the pivot bearing, the pivot arm, tensioner damper, and the cone-like section of the front timing chain cover where the tesioner bearing is mounted to.

Look for finer cracks that start to come together in a complete circle all the way around the base of that cone.

There should be very little play in the tensioner bearing and the belt should ride completely on the idler wheel surface, not hanging partly off of it.

The tensioner damper / shock should have firm and consistent resistance to force in either direction. there should be no 'dead spots' along its travel.

Diseasel300 · #25 06-27-2016, 07:15 PM

Tensioner arm, spring, damper, and pulley already replaced. Pulley was still good, but damper had 0 resistance, spring was likely stock, and the tensioner bearing was "chunky". Both pulley and arm bearing were missing their caps, so I just replaced it all knowing it was bad. Front cover in good shape, free from cracks and damage. Despite the nearly seized arm, the belt was still riding true on the pulley, I can only assume it seized up with all the sitting it did, so no real damage to the engine or accessories as a result.

I will say that replacing the belt is a serious PITA on this car! Didn't enjoy it. Will probably pay someone to do it next time, that's how much I disliked it. Pulling and reinstalling the head was easier, hand to God.

The car is amazingly stock for it's age and mileage, so known issues are getting attention first. I intend to keep the car for a while, so do it right the first time and all.

barry12345 · #26 06-28-2016, 03:22 PM

For what it is worth. When getting an old engine or system back into reasonable shape. Not being the smartest on the block myself.

I find faults and replace/repair them one at a time. Then run the engine. As soon as I am satisfied with what I have addressed I move on to see if there are other issues.

If more are found or known I tackle them one at a time as well. It may not seem logical but can avoid the accidental introduction of another problem that may leave you wondering.

What have I changed that is making the new problem perhaps otherwise? Or was it part of the old problem to start with? For example just changing the delivery valves seals alone can introduce issues that take substantial miles to work themselves out on occasion.

My approach in general is that the old diesel Mercedes cars I have purchased. Are usually pretty much an unknown as to what if any service they have had if any. Especially on the fuel systems over the years.

I never claim my approach is for everyone . At the same time my not being a real full time mechanic by any extent means I want to take precautions.

I am really a strong minded person about doing a general full checkup of the old fuel systems in these cars. Usually you will probably find something and if not that is also fine. What you have done though is to improve the reliability or suspected reliability of the system is now much better.

Depending on your equipment I would remove the fuel tank cap and blow out the return line. From the engine compartment. Especially since you seem to have found the relief valve totally open. Also there is a little valve on the end of the vent line for the fuel tank.

Clean it and make sure you can blow up the vent line to the fuel tank. Both may be okay or one or the other may be semi restricted. Just other simple age things seen on occasion primarily with these older diesels.

Again your cars engine type can really move that car when the fuel system is doing everything it was designed to do properly. To me it is always worth the effort.

Diseasel300 · #27 06-28-2016, 05:55 PM

Barry,

I generally share your same mindset when troubleshooting, I like to do one thing at a time. In the case of this car, it has so much sitting time and so much that's still 1986 stock original on it, that some things are getting clumped together and done all at once. After discovering that the IP was out of time, I decided to do the valves while I had the IP out on the bench.

I intend to keep the car for a long time, and I also intend to drive it on trips, so I want it to be done right! It has a lot of potential, and I've ironed out an enormous number of problems with nothing more than a bit of elbow grease and sweat equity. It's a lot of work and very time consuming, but I enjoy it, it's the whole reason I bought the car in the first place.

The "fuel system" is currently a 3 liter polypropylene reagent bottle leftover from some old production process many moons ago at work, since I know the fuel tank is full of really nasty old diesel and needs cleaned. Next thing on my agenda after getting the engine running is to pull the tank and have it cleaned (nasty old green fuel in it!), replace the tank strainer, and clean out the supply/return lines under the car with compressed air.

I want it to run like it's supposed to and not leave me stranded somewhere, it seems like it has the potential to do just that once I get it running properly. Lots of time, a bit of money, and feedback from others on here that have done it and know more than I do is all that's needed. I'm aiming to have the thing running, and hopefully back on the road by Fall. The engine is really the last big hurdle holding me back right now, everything else is in good shape and working like it should.

barry12345 · #28 06-29-2016, 11:08 AM

Great you are still on the bottle.

As soon as you get your new relief valve installed. Have a look for the return line producing output.

If you like the car kind of start a hunt for a better number head at a cheap price. It will be a case if you have it you probably will never need it. If not hard to tell.

But obtained cheap enough while still out there you can resell it for decent dollars someday. They are getting scarce to some degree but at the same time your part of the country could still prove productive for a cheap one.

Some members have found them for fifty dollars at pick and pulls.

My guess is that by running the original number head. When the engine is hot letting it idle for a minute or so before shutdown may equailise any hot spots. Reducing the cracking chances somewhat. Also I suspect there were some alloy issues as some of these # 14 heads did not do well in a hardness tests in comparison to other # 14 heads.

One of our members spotted this years ago. This difference in alloy consistency may also be a reason some #14 heads go the distance and others not.

In any event this requires the original engine cooling system be well maintained as well. Personally I would run a water wetter.

To me these engines are somewhat like a racing quarter horse. They are a little fussy about their requirements. Even tempermental to some degree. Yet can really run and perform exceptionally well.

Personally I would like to own a good 1987 603 engine in a 300d.

I guess I will post one last thing. At cold startup when the glow plugs cool off you may initially find a roughness in idle. It does clear out as soon as some temperature is gained in the cylinders. This is fairly common on these 603 engines. Just do not figure it is a problem.

If you want to do something about it eventually. Junkyard afterglow glow plug relays are out there. You may already know about this but just in case you missed it in your reading.

Diseasel300 · #29 10-21-2016, 09:53 PM

So this is an old thread, but I hate leaving threads open-ended. Been discussing the injection pump in detail on another thread and it seems the IP turned out to be the issue all along. The rear ball bearing on the IP camshaft came apart and the camshaft has just been flopping around in there this whole time. New IP will be going on soon, but I figure I'll link to the other thread for the final conclusions (and some photos of the IP).

300SDL - IP Issues?

barry12345 · #30 10-22-2016, 02:24 PM

Uncommon failure perhaps? Hindsight is so great though. There is also a chance the failure is still occurring periodically for others but the injection pump gets changed without actually knowing the internal fault.

When things get complicated it is still best in my opinion to use certain testing. You unfortunately had it about as bad as it gets for a set of symptoms. Someone had played with this car before you got it. That usually results in more difficulty.

Nobody likes or always finds it easy cleaning up some other persons mess. I hope and doubt you will ever have to deal with worse on this car in the future.