NOOB adventures in Diesels - PeachParts Mercedes-Benz Forum

dirtwater · #1 04-02-2016, 11:25 AM

Greets,

Long story sorta short, I bought 3 - W124 MB's last year and got a little overwhelmed with needed repairs as I was also replacing a 2nd daily driver at the same time (a 1982 SAAB 900 Turbo) with two newer daily drivers...a 05 A4 and 08 GTI. Out of the W124 MB's I kept the non-driverable 1990 300D 2.5 Turbo Diesel because parking spaces are very scarce for Me. Anyway the 300D has rear subframe issues to tackle among other general repairs to be road ready. Originally I bought it as a W124 parts car and wasn't sure I was ready to start playing with diesels just yet.

I have only driven this car once and that was over to a friends for storage last summer. I had decided I was done with wrenching on old cars for awhile earlier this spring and listed it locally on CL. I hadn't visited to 300D since fall and it sat all winter. Anyway I went over to jump start the car a day prior to selling it. It started within a couple of seconds with barely a jump and one glow plug cycle on a 20 degree day. it settled right down to a decent idle and I was taken aback, amazed, floored etc. This car had been sitting since last summer and it kicked over like it was running just yesterday. So yeah I couldn't sell it and like an idiot I kept it.

I still am not quite sure what My plans are for it but I couldn't see it going to the scrape yard which is why I bought it in the first place. I have about enough skill to fix this one or use the engine as a swap...decisions, decisions.

I started messing about with it a couple of weekends ago and I purged the engine with 2 cans of Liqui-Moly, What a difference. This week I ran one more can of purge thru it before I changed the primary and secondary fuel filters and got a quick lesson on bleeding the fuel system. I solved that by cracking a banjo fitting open. I also changed the engine oil filter and the engine oil. I had no idea of what type syth. or conv., brand etc was in the engine or how long. That said I filled it with Mobil Delvac 15w40 since summer is coming, it was on sale at NAPA and I am a Diesel NOOB. I went with all Mann filters, a habit I have been trying to keep going since I started messing around with old Audi's.

So I have a couple of questions.

Isn't there a hand prime pump option available for the fueling system that isn't a add on bulb-hose type? I could not find a fuel prime handle or plunger anywhere on the IP.

Can engine pinging be caused by old valve lifters and or both old injector nozzles. It seems to be such conflicting info on these engines. I think My om602 is pinging a little but since I am new to diesel noises I am not sure entirely. I did take a video post purge, fluid and filter change and should add as a you tube link.

a little white smoke? this car smoked a fair bit at idle...purge got rid of that smoking about 99% and smoothed out the idle a bit. back on the diesel from the tank it is smoking again a little bit at idle again, not nearly as bad as pre-purge maybe 10-15% than before? Old diesel? the tank had (a rough guess) 2 gallons pretty old well over a year or two, 4 gallons of newer last summer and 7-8 gallons of fresh a month ago diesel in the tank so IDK?

After playing around a bit with this one, doing a ton of online reading on the OM602 and MB diesels in general and owning a couple of diesel tractors in the past that I loved I can't figure out for the life of Me why I didn't get into these years ago?

Sorry for the long winded first post and Thanks in advance for any input.

C.

t walgamuth · #2 04-02-2016, 12:02 PM

Old diesel is not likelty to cause white smoke. Cannot speak for any other fuel which might have been in it at one time. And it keeps pretty much forever. I had some heating fuel in the basement of my building which I estimated to be at least 40 years old. PUmped it out and it ran in my 350SDL just fine.

Your valves could tick if you have the wrong oil in it.

shertex · #3 04-02-2016, 12:21 PM

The OM602 is self-priming. Make sure the canister filter is filled with fuel and crank, crank, crank till it starts.

dirtwater · #4 04-02-2016, 01:30 PM

yep, I wasn't thinking bad is in old gas but bad as in being 'Hygroscopic' from sitting in the tank for prolonged periods of time and absorbing H20 I always thought that was a issue for marine diesels that sat idle for long periods on time.

As far as the self-priming thing I did initially think that was the case that it might be self priming when I couldn't find a handle or plunger. I did fill the secondary filter with fuel prior to reinstall. It did try to fire briefly and I assume that was what was left in the IP before it became air bound? and just spun the crank there after. I did try 3 three times to kick it a over but was after that I didn't want to put any un-due load on the starter or battery if it really needed a actual air bleeding.

Below is the video of it running post purge, fluid, filter and prime. I made note of the linkage of the left side of the engine early in the video (Transmission related?)of course I pulled it in the wrong direction

nevertheless I thought most of the linkage seem loose. Anyway it seems to idle okay but I can hear a slight tick? nailing? and maybe a tiny skip? IDK? like I said diesel noob...I am not sure what a perfect running om602 sounds like in person.

https://youtu.be/ILb7sEnzSG8

https://youtu.be/wlgZeVpgru0

Thanks

C.

babymog · #5 04-04-2016, 07:41 AM

Agree ^^ and agree ^

Old diesel should run fine. I have a loader that sat for about 15years, started and ran fine on the fuel. If there isn't water or "algae" in the fuel it will run fine, if contaminated it simply won't run on water nor on clogged filters.

Pinging sounds like a normal cold 602, white smoke sounds like a normal cold diesel. If the white smoke hangs around, it is smoke, if it dissipates quickly or smells or anti-freeze it is steam (bad).

If you can get the car out and drive it a little to get the engine warmed up you should have a better idea of what the sound and smoke really is.

tombance · #6 04-04-2016, 09:11 AM

Agreed. Go and give it a good drive around. Find a long steep hill and put your put down to get it hot and blow out the carbon.

Maxbumpo · #7 04-04-2016, 02:57 PM

WARNING: you've now contracted dieselitus maximitus. There is no cure. No family intervention can help. Soon most of the cars in your household will be old MB diesels; don't resist or fret, just try to pace yourself, keep an even flow.

I can hear an occasional miss in the first video. If the engine was cold, that should go away when warm.

If you goal is to get the engine running perfectly, I'd start by sending the injectors to Greazzer for cleaning, checking the spray patterns and setting the pressures.

If you've still got a miss and smoking, and you've done the diesel purge thing which normally would be the first thing to do with a rough idle and smoke, then you could think about rebuilding the delivery valves (new copper washer, new springs, and new O-rings). Research that job before you dive in, special tool(s) required and special torque procedure when re-installing the DV's. Poorly sealing copper washers can cause idle problems like yours, but so can other things (like injectors).

dirtwater · #8 04-08-2016, 09:31 AM

Thanks guys. Will proceed with suggestions and report back.