I started this "confounded..." thread way back in fall 2012 and instead of adding to that thread (where the actual problem was fixed) I'm going to start a new one that actually deals with my car's issues.

I drive a naturally aspirated 1978 300D with just under 300,000 miles.

Currently, I have a few things going on:
Nailing
Trans leak
Oil leak (either in the cooler or one of the hoses)
Evil servo leak (I'm fixing this very soon)

Nailing.
I've asked about the nailing and it could be coming from dirty injectors, fuel delivery or a host of other problems.

A few days ago, I fueled up with regular diesel instead of the usual B20 and my nailing has gotten worse. I added a couple ounces of cetane boost at the time I added fuel and with normal diesel, the car just nails under accelleration most of the time unless it gets good and hot then I'm driving at a constant highway speed.

I haven't checked the screen in the tank but it could very well be pretty clogged.

A few weeks ago I did a purge and bled my injector lines as well as adjusted my valves (and changed oil.) The nailing got a little better after the valves/purge/line bleed but I was running B20.

I haven't chacked the timing chain stretch and I know this needs to be done but even if it's stretched, I don't have the space to work on the car here on the street.

Even doing a purge, I can get te engine to nail a bit but not nearly as much as with regular diesel and under a load accellerating.

The pressure relief valve has been discussed as has fuel line constriction, tank breather clogs and tank screen clogs. My filter always has black grains coming out of it after I do a purge so I know there is a lot of crap running through my fuel system.

One member mentioned water in the tank getting into my fuel system and possibly causing nailing. This is a possibility since I had a nice window seal leak almost right above the fuel gauge sender and I'm sure the condition exists where water could have weeped past the seal on the sender and gotten into the tank. I will say that nailing is worse on rainy days but they also happen to be colder too.

I haven't done my IP timing ever.

As has been mentioned, I also probably have dirty injectors. As soon as Uncle Sam pays me back I'm going to either rebuild my injectors or replace them outright. As long as that job wouldn't be too hard to do the injector swap on the street, I could do it, I'm pretty sure. While I'm at it, I plan to ream out the glow plug chambers.

Am I missing anything regarding nailing?

Oil leak.
I'm on my second cycle of using pure synthetic and just a few days ago I noticed that either my lower oil cooler hose is leaking close to the nut that attaches it to the cooler or the cooler itself is leaking. I doubt it's the cooler itself but I need to get in there with a mirror and a light to really check.

I've heard differeng opinions on oil additives and I'm not a fan of them myself, prefering to really fix a problem rather than apply a band-aid to it. That said, could some of the LubroMoly oil motor oil saver do an ok job until I get this issue fixed? I don't want to cause any more trouble by possibly clogging up passages in my engine.

I knew that with this change to synthetic oil I could possibly see leaks and so it's begun. I keep close tabs on the oil level and I haven't lost more than a few tablespoons in a couple hundred miles. I JUST changed the oil though about 2 weeks ago and I'd rather go at least a few thousand miles on this cycle rather than change it out.

Transmission leak.
It leaks out the front end of the tranny. Supposedly from the TC seal. I monitor fluid level and keep it right as much as I can. Again, in this case, I don't want to put any sealing products into the transmission.

Evil servo leak.
Gonna bypass it this week.

I think that's all. My biggest issue is nailing and the main issue I have with maintaing the car is that I don't have space to do it and it has to be moved every two-or-so days for street sweeping so big things like timing chain replacement are out. Anything that can put the car OOC for more than a couple days is out. Granted, if I don't take care of these issues, the car is going to be OOC sooner or later.

Apologies for the short novel here.

Phil Forrest

__________________
1972 220D "Trudy," named by a friend.

"The 220D sounds good... I suspect it is the only car that you need a calendar for, rather than a stopwatch, when doing acceleration tests."
Tom Abrahamsson

If that's all then I'd say you're doing OK.

Nailing- definitely service the injectors asap. If you sill have nailing after that then go from there.

Oil leak- I'd be watching it like a hawk. Be a real shame to loose your oil there and kill your engine. Probably would t even notice until it was too late.

Trans leak - TC drain Plug or trans front Pump seals. Both gaily common leaks but one is extremely easy to corect and the other is not. I have a $650 price quote from my mech to fix the front pump seals on mine.

Servo - it's just one of those things... Did mine years ago and went straight forthe electronic upgrade. That'd be the only Soltion that I could weigh in on.

Good luck.

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Current fleet
2006 E320 CDI
1992 300D - 5speed manual swapped

former members
1984 300D "Blues Mobile"

1978 300CD "El Toro"

I'm definitely watching the oil. I've thought about just getting a wrench and tightening down the nut a bit then cleaning off the old oil and seeing where the leak is actually coming from. I don't want to inadvertently break the seal in there and cause a worse leak though. I just haven't had time to do this. I'm going to get under the hood tomorrow to investigate further.

The trans leak is the pump seal. An indy mechanic in Albuquerque diagnosed it last fall and I've been hoping to get some space to drop it and change the seal myself but it looks like I'm going to have to pay a mechanic to do it. Problem is that I have no idea out here in north Jersey who to trust.

And the nailing is as you say. Just needs to be taken care of ASAP but life has "happened" to me a few times over the last few months and a couple difficulties thrown at me which have forced me to spend money in other places.

I just wish I could do the work myself but without the space, I'm limited to little jobs that can be done in a few hours.

Phil Forrest

__________________
1972 220D "Trudy," named by a friend.

"The 220D sounds good... I suspect it is the only car that you need a calendar for, rather than a stopwatch, when doing acceleration tests."
Tom Abrahamsson

Nailing; something happening in the Precombustion Chamber causing the Fuel to burn at the wrong time. B20 and the Cetane Booster have a higher Cetane rating that Disel so it starts burning sooner and that sort of mask the issue.

Besides the worn Injector issue where low openg Pressure and worn seats in the Nozzle cause poor atomization there is late timing due to:

Timing Chain Stretch and Timing Gear wear (also causes late Camshaft timing)

Late Fuel Injection Pump Timing

Air leaks can also cause Nailing.

Low compression can cause nailing till the Engine is warmed up. But, a long with that you would likely have more trouble starting in Cold Weather.

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84 300D, 82 Volvo 244Gl Diesel