As you all know I recently purchased a $300 running and driving 300D 2.5 that needs some work. It has 310k miles on the clock. Just started it today to move it a couple feet. It starts up after 3 cycles of glow plugs, is a little rough to start. It smokes white until it warms up, and if you don't keep on the pedal it wants to stall out first at idle. When it warms up, it idles fine, and is easy to start backup until its cold. It still has a shaky motor however. It is also very low on power, absolute dog! Couldn't make it up a hill to save its life.

No oil in coolant or oil. Both are clean.

Tomorrow I'm going to evaluate engine timing and turn the crank and align the cam with cam bearing cap mark and see what its at and also feel the chain and see how tight it is. I'm assuming this is a combo of worn glow plugs (hence cycling the GPs 3 times to start it easier, at least 2 dead plugs), worn injectors and timing retarded or advanced. Depending on the stretch i'm going to replace the trails and chain & tensioner.

Please shoot me ideas!

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Only diesels in this driveway.
2005 E320 CDI 243k Black/Black
2008 Chevy 3500HD Duramax 340k
2004 Chevy 2500HD Duramax 220k

First thing I would do is a undiluted Lubro-Moly Diesel Purge, run a couple cans of that on a short loop closed circuit through the IP, injectors and secondary filter.

When ever you fool with the fuel/IP/injectors on these OM 60X engines ALWAYS get the engine started and run it until it's up to operating temp 85C first! Then do what you need to do as far as fooling with the fuel system.

It's always easier to start a warm engine that a cold one, particularly engines that have no fuel prime pump facility. Lots of examples of people failing to do this ending up having problems with batteries and starters trying to get them started after opening the fuel system.

That is on order. I ordered pre-filter and main filter and two cans of diesel purge. I truly believe it needs glow plugs badly since its 40 degrees with lots of wind and it needs to be cycled a few times to start and still wants to stall and smoke white/grey.

Which line is the in-line and return line on a OM602?

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Only diesels in this driveway.
2005 E320 CDI 243k Black/Black
2008 Chevy 3500HD Duramax 340k
2004 Chevy 2500HD Duramax 220k

After running the Diesel Purge replace the secondary canister filter, you have no idea how long the present filter has been in place, no ideaa what fuel has been run through it, and no idea what contaminants have been trapped inside it.

Looks like you live a a place where it freezes, the canister has a cotton filter media that is designed to absorb and trap water in the fuel, that trapped water can freeze impeding the flow of fuel.

Once that is done you can use the setup that you used to run the diesel purge now filled with straight diesel to figure out if the sluggish power is rpossibly related to the fuel system from the engine compartment to the tank.

If it runs better you might be having some problem with either the fuel in the tank, the screen in the tank or even the lines from the tank to the engine. If the engine is still sluggish the problem might lie elsewhere.

Lack of apparent turbo boost is often related to the over-boost protection system being clogged with carbon and preventing the ALDA from allowing sufficient fuel enrichment when the increased turbo pressure kicks in at about 2400 RPMs.

You can check if that is a problem by disconnecting the overboost protection solenoid valve out of the circuit and running a clean unplugged line from the fitting on the intake manifold(assuming you've verified the fitting is not itself clogged) directly to the ALDA. If that was the problem doing so will restore turbo boost signal to the IP's ALDA.

OK yeah you want to ensure it's getting fuel first.

You can always plug the block heater in to assist cold staring as you work to straighten things out.

Yeah you might as well get glow plugs done before it gets colder, BOSCH or BERU. Unless your a masochist removing the intake makes it easier. You'll need replacement gaskets at the cross over pipe and an intake gasket.

Once you get that out of the way and you've disconnected the wiring loom from the relay spray the 8mm nuts on the glow plugs with penetrant, grasp the wire terminal itself with a pair of large long needle nosed pliers and then you can put a socket on the terminal nut. That will prevent you from damaging the wire-to-terminal connection and keep the nut "captured" onto the terminal like it is designed to be. Take your time and be thoughtful to prevent causing any damage that will then need to be addressed and repaired if you don't!

Having the engine at running temp before you start the glow plug R&R makes this easier as well. Penetrant on the GPs can never hurt.The GPs are 12mm, I try to break them free with a box wrench and then use a medium deep socket with a swivel to back them all the way out. Ream the holes and install the new GPs, I use a bit of Permatex Never-Seize on their threads

Actually a compression test would be my first order of business. Spending money and finding out later it is low. In perhaps a cylinder or more can prove wasteful. There is information posted on site of how to check the timing chain free for really excess stretch as well.

I am not suggesting what the problem is but I personally like a baseline to start with. Attempting to build on a perhaps rotten foundation can be a waste of resources. Yet if the compression is fairly decent is another story.

I am not sure or not yours is the engine model that develops deeply recessed valve pockets on occasion.

It may just be the glow plugs but you can check them for free other than a little time. An engine at about 40 degrees out does require them to be working if not perfectly at least somewhat. That white smoke you are seeing could be un burnt fuel. Another free test is to loosen each injector line in turn to determine if all the cylinders are firing. Simply because you state the engine is quite rough at idle.

Fuel feed and return off the top of my head the top line is the feed and the bottom the return, but I could be wrong. Just make note what's what when you disconnect it. If there is much fuel in the tank you can just use a piece of rubber fuel line to form a loop capping both the feed and return together to prevent gravity from draining the tank while it sits.

Fuel flows from the steel feed line to Primary filter, to the fuel heater thermostat, then to the IP fuel pump, to the secondary, to the IP.

The Fuel Heater Thermostat can be plumbed out of the circuit it necessary, they often leak but they are a pretty easy cheap repair.

If you're getting deep into that fuel circuit you might end up replacing fuel lines, if you do be aware that the proper MB hose clamps often times work much better than generic screw type band clamps. You can't allow leaks in the flexible lines where they connect to the steel lines and the bibs on filters and such or you will be sucking air into the fuel feed.

A valid compression test can only be accomplished on an engine that is at operating temperature, no one should fool themselves otherwise.

While a good indicator of an important element of engine health it only can eliminate compression failure as root problem, it does little to diagnoses what other fuel or timing issues might effect poor running problems.

I will start with a diesel purge and see what it does, then replace pre-filter and the spin-on filter. Compression tester is in order of purchase as well.

__________________
Only diesels in this driveway.
2005 E320 CDI 243k Black/Black
2008 Chevy 3500HD Duramax 340k
2004 Chevy 2500HD Duramax 220k

Look into the wastegate actuator swap. It made a huge difference on my dads 92 300D 2.5. We spent a long time chasing vacuum leaks and keeping the factory system working, but after one too many days with random no-boost conditions I spent the $100 and like 2 hours to do it, set it at whatever the factory peak pressure is (12-14psi?) and haven't touched it in years nor had any issues with boost.

Like everyone else has said though, compression test is the best place to start. No sense in throwing good money after bad if you've got a dead cylinder. You can shovel all the boost and diesel purge in the world into it and with 0 compression it still won't matter.

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68 280SL - 70 280SL - 70 300SEL 3.5 - 72 350SL - 72 280SEL 4.5 - 72 220 - 72 220D - 73 450SL - 84 230GE - 87 200TD - 90 190E 2.0 - 03 G500

Nissan GTR - Nissan Skyline GTS25T - Toyota GTFour - Rover Mini - Toyota Land Cruiser HJ60 - Cadillac Eldorado - BMW E30 - BMW 135i

Agree with the compression test being first order of business for a motor that starts/ runs rough with no history on motor. If it starts/runs perfect from cold then don't bother with a compression test.

As for cold vs hot compression test both are valid IMO. If you get cold 400 psi on all cylinders wouldn't you like that and accept that as good indicator and go on to do a hot compression test? I would. OTOH if you get cold 400, 400, 50, 400, 400 you know you have a serious problem. In which case I wouldn't wast time to do a hot compression test, and do a leak down test instead to see where the big leak is coming from.

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85 300D turbo pristine w 157k when purchased 161K now
83 300 D turbo 297K runs great. SOLD!
83 240D 4 spd manual- parted out then junked

Unplug your MAF and go for a spin!

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92 e300d2.5t
01 e320
05 cdi
85 chev c10

BIG Update... Determined a lot today on the car by pulling the main filter.

All cylinders are getting fuel. I'm about 100% this issue is caused by a combination of bad diesel, and water in the fuel as well. I took off the main filter and poured it in a cup. It's black, has water, and has dirt particles everywhere. It had a ton of air in the system as well too after I bled the system and prior to removal of the filter. I'm thinking the injectors are clogged as well. I'm thinking a purge is going to make a large difference. The pre-filter is completely black as well.. I'm going to run a purge and update when I recieve the purge, and filters. I'm also draining the fuel tank and running fresh diesel through it.

Thank you everyone so far for your responses. I'm going to look into all the issues you've mentioned as well.

Also, found a bunch of vacuum lines disconnected and cracked. Reconnecting the missing ones helped shifting. Still shifts hard, but there is a ton of deteriorated lines as well.

__________________
Only diesels in this driveway.
2005 E320 CDI 243k Black/Black
2008 Chevy 3500HD Duramax 340k
2004 Chevy 2500HD Duramax 220k

You might need to clean the tank to get rid of the black stuff. Pull the tank strainer for an idea of what you're dealing with.

Sixto
83 300SD

Yup I was thinking that. It's probably nasty in there. It could be algae the particles I'm seeing. I might pick up some Biocide for the tank.

What's the best method for cleaning the tank? Just a pressure washer and letting it dry?

Also, from what I've found is that enough to make this motor run like garbage?

__________________
Only diesels in this driveway.
2005 E320 CDI 243k Black/Black
2008 Chevy 3500HD Duramax 340k
2004 Chevy 2500HD Duramax 220k