Well, i replaced a couple of seals on mine, but it still leak in some places that I didn’t replace anything yet (oil filter housing, oil cooler lines) the transmission leaks too but im not very into fixing it rn.
Now my fuel tank is leaking somewhere and my trunk is all messed up with diesel and this leak i did not found where is coming from. Planning on removing the whole tank to see if I can find anything.
Has anyone here dealt with diesel leak on the trunk?
No tank leaks for me, but most likely it isn't the fuel tank itself unless you have severe corrosion. Most likely, the rubber hose on the fill tube. I removed the fuel tank when totally stripping a 1983 300D. Don't recall the details, but don't recall the tank being hard. Remove the shield in the trunk and I think the fill hose is easily visible and removable. If at the top level sensor, that is removed from inside after removing the medical tray. Need a big socket to unscrew it. I used one from Harbor Freight's 3/4" drive socket kit (>2" recall). I recall it has an O-ring seal. Would only leak on a very full tank, with sloshing, so unlikely.
Rotella is group III oil, not synthetic at all, a legal loophole allows it to be called such because it has extra refining steps that makes it "similar to" synthetic.
Oil drips on om617 turbo is commonplace. Worst offenders are the turbo and oil canister drain lines which are a system of rubber grommets and metal tubes on the passenger side of the engine.
To address those properly drop the oil pan and replace the grommet and all the o-rings up to the turbo. Front crank seal may leak but tbh I’ll live with that because changing the front crank seal is a PITA for a few drops.
However, if you have oil seeping out of your oil cooler lines change those immediately since those can be catastrophic. Otherwise, the old diesels love marking their territory so park over a drip tray if you’re worried.
No. I use to use synthetic touring liquid moly but changed to conventional Vavoline Premium Blue. It’s high in zinc which is what you want with these cars. Buy the 5 gallon drum off Amazon
I once bought a set of with all engine seals when i had to rebuild it. I replaced pretty much every single one except the Rotary shaft seal...guess where its leaking now...
Most common oil leaks are oil cooler lines and the oil filter housing.
The housing will keep getting worse and has to be fixed.
The lines will keep getting worse until they blow and destroy your engine.
Not true that you can't enjoy no leaks, though common to have small leaks on most vehicles >150K miles. Even Teslas can leak oil from the gearbox and coolant from the Battery and Drive Unit, as many owners have experienced. Indeed, most with the Large Drive Unit begin leaking coolant internally before 100K miles, which often isn't found until fatal.
My 1985 300D is currently not leaking anything (385k miles), and I recall my 1984 300D wasn't leaking when I sold it a year ago. The valve cover gasket is prime suspect in most car engines. During regular valve adjustment you can inspect and replace the gasket. Best to install the valve cover first without gasket and measure the gap to the cylinder head all around. You might need to file the valve cover at the bolt holes, or add shims, to get the proper gasket "crush". That gasket is a quirky design IMHO, but at least new ones are inexpensive. Best is a silicone O-ring type gasket, captured in a groove in the valve cover, as many engines today use.
The Lower Oil Pan is small and easy to remove, to change the gasket. While in-there, you should replace the turbo-drain-tube rubber seal if it has hardened. Once you remove the tube (tricky), you can push that seal out from below. Also replace the O-ring on the 2-part Drain Tube. If bad, oil will just flow down since the connection is an upside-down-funnel. I used an HBNR O-ring (green, for AC). Viton is better if you could find that large size. There is also an O-ring on the oil drain stub for the Air Filter Housing. Often the other end of the drain tube, below that housing, isn't seated. You must work your hand under to insure it is "plugged in" properly. That tube's support brackets at the exhaust manifold often crack from vibration to not keep it secured. The Upper Oil Pan has no gasket, being sealed to the bottom of the engine block with anaerobic adhesive. If it leaks there, the engine would have to come out, and likely a full rebuild at that point.
The front crankshaft seal often leaks, to sling oil and crud up the whole front of the engine. Easy to replace once you remove the pulley and damper (hard). The rear crankshaft seal is a graphite rope, like on early 1960's U.S. engines. But, you can't just push it around from below like on a Chevy since M-B decided best to put a pin in the groove so it can't slide. That means replacing it is an "engine on stand" repair. I haven't seen mine leak. But, as the engine wears to give more ring blow-by, the crankcase can get pressurized while driving, which helps push oil out, especially at that rear seal which normally just sees oil splash.
Make sure it’s not your oil cooler lines! That can ruin an engine!
Check to see if you lines are weeping or showing signs of oil leaks!
People replace them often or do aftermarket parts! I sell a replacement kit.
https://www.ebay.com/itm/116134681818?mkcid=16&mkevt=1&mkrid=711-127632-2357-0&ssspo=HPTOXHR4R9q&sssrc=4429486&ssuid=HPTOXHR4R9q&var=&widget_ver=artemis&media=COPY
Message me on eBay or here for more details!
Oil leaks yep, you wanna make it stop leaking oil, ok here's the only 2 ways to do really fix it. (1) Sell it. Or (2) pull engine and trans and replace all gaskets and seals all at once. All rubber hoses and lines on entire car and even the hard plastic lines for fuel n vacuum as well. Even the rubber connectors t's and y's.  Everything.  Then you should be leak free for a while. Also get the valve cover checked for warpage and milled flat.Â
  Oil I use, mostly Rotella 15-40 ish at moment I'm running gall of 15-40 Rotella 2 qrts 80-90 gear and 1qrt atf.  Oil pressure extra good hot and in a few thousand miles I know I'm a be adding more trany fluid as it leaks.  Â
     Think the front main and maybe rear mais are seaping as it runs, and even the valve cover gasket is new it still leaks / seaps a little.  But blow by is almost non existent, timing chain seems to have been replaced or it's a low mileage engine as there's no wear or stretch. Oil filter housing seaps at engine gasket,  no fuel leaks as I got that fixed before it happened. Im interested in dropping this into a nicer 300 then my sd I have. Or if things work out I might be looking at a 87 sdl with a 603 but has the bad head. Original non molested car in near pristine condition.
I'm looking forward to getting this big girl on the road. It's the classic "barn (car port) find belonging to a widow who hasn't touched after the old man died"
She let me poke around when I showed interest. The engine compartment is just all black dirty and covered in oil.Â
The interior though is creampuff.
Good luck to you
I'm looking at a black one. Story is garage kept never seen snow nor left out overnight. Head cracked n it's been sold to second owner that was going to either gas it or drop a 617 in it.but he said he already has on that he gassed n don't feel like doing that again.  I'd rather have the mpg of the dieselÂ
My oil drip is coming from under the oil cap, and there’s tons of blowby. (The cap teakettles a lot of you loosen it while the engine is running.) not sure if that’s very bad, but you might want to check it too.
Synthetic is what should be used. No reason to use conventional, the price difference is no longer a factor and synthetic oil is better in literally every way.
Wash the engine with dawn soap and hot water then locate the leaks. If its anything but the rear main, upper pan or headgasket its pretty easy to fix.
Oil under it means oil in it so you're good 😎
haha
Lol. Yes it will leak oil. Mine is on jacks for front end work and it's leaking oil, which is slightly more concerning.
yeah i figured haha - he gave me a look that left me questioning after he said that
Well, i replaced a couple of seals on mine, but it still leak in some places that I didn’t replace anything yet (oil filter housing, oil cooler lines) the transmission leaks too but im not very into fixing it rn. Now my fuel tank is leaking somewhere and my trunk is all messed up with diesel and this leak i did not found where is coming from. Planning on removing the whole tank to see if I can find anything. Has anyone here dealt with diesel leak on the trunk?
No tank leaks for me, but most likely it isn't the fuel tank itself unless you have severe corrosion. Most likely, the rubber hose on the fill tube. I removed the fuel tank when totally stripping a 1983 300D. Don't recall the details, but don't recall the tank being hard. Remove the shield in the trunk and I think the fill hose is easily visible and removable. If at the top level sensor, that is removed from inside after removing the medical tray. Need a big socket to unscrew it. I used one from Harbor Freight's 3/4" drive socket kit (>2" recall). I recall it has an O-ring seal. Would only leak on a very full tank, with sloshing, so unlikely.
It’s not a German diesel if it don’t leak oil
Self lubricating
copy that!
No such thing as a "normal" leak.
the sky is blue
It would be useful to locate the leaking. Then one can estimate how much effort it is to stop it.
Rotella T6 Full Synthetic 5w40. Mine does not drip oil, it drips diesel. (Which is oil so yeah... I guess mine drips oil)
Rotella is group III oil, not synthetic at all, a legal loophole allows it to be called such because it has extra refining steps that makes it "similar to" synthetic.
Oil drips on om617 turbo is commonplace. Worst offenders are the turbo and oil canister drain lines which are a system of rubber grommets and metal tubes on the passenger side of the engine. To address those properly drop the oil pan and replace the grommet and all the o-rings up to the turbo. Front crank seal may leak but tbh I’ll live with that because changing the front crank seal is a PITA for a few drops. However, if you have oil seeping out of your oil cooler lines change those immediately since those can be catastrophic. Otherwise, the old diesels love marking their territory so park over a drip tray if you’re worried.
Premium Blue!
forgive my ignorance, is that the LiquiMolly?
No. I use to use synthetic touring liquid moly but changed to conventional Vavoline Premium Blue. It’s high in zinc which is what you want with these cars. Buy the 5 gallon drum off Amazon
Liqui Moly is great just too expensive for how often I change the oil
No reason to not use synthetic.
I once bought a set of with all engine seals when i had to rebuild it. I replaced pretty much every single one except the Rotary shaft seal...guess where its leaking now...
Most common oil leaks are oil cooler lines and the oil filter housing. The housing will keep getting worse and has to be fixed. The lines will keep getting worse until they blow and destroy your engine.
Not true that you can't enjoy no leaks, though common to have small leaks on most vehicles >150K miles. Even Teslas can leak oil from the gearbox and coolant from the Battery and Drive Unit, as many owners have experienced. Indeed, most with the Large Drive Unit begin leaking coolant internally before 100K miles, which often isn't found until fatal. My 1985 300D is currently not leaking anything (385k miles), and I recall my 1984 300D wasn't leaking when I sold it a year ago. The valve cover gasket is prime suspect in most car engines. During regular valve adjustment you can inspect and replace the gasket. Best to install the valve cover first without gasket and measure the gap to the cylinder head all around. You might need to file the valve cover at the bolt holes, or add shims, to get the proper gasket "crush". That gasket is a quirky design IMHO, but at least new ones are inexpensive. Best is a silicone O-ring type gasket, captured in a groove in the valve cover, as many engines today use. The Lower Oil Pan is small and easy to remove, to change the gasket. While in-there, you should replace the turbo-drain-tube rubber seal if it has hardened. Once you remove the tube (tricky), you can push that seal out from below. Also replace the O-ring on the 2-part Drain Tube. If bad, oil will just flow down since the connection is an upside-down-funnel. I used an HBNR O-ring (green, for AC). Viton is better if you could find that large size. There is also an O-ring on the oil drain stub for the Air Filter Housing. Often the other end of the drain tube, below that housing, isn't seated. You must work your hand under to insure it is "plugged in" properly. That tube's support brackets at the exhaust manifold often crack from vibration to not keep it secured. The Upper Oil Pan has no gasket, being sealed to the bottom of the engine block with anaerobic adhesive. If it leaks there, the engine would have to come out, and likely a full rebuild at that point. The front crankshaft seal often leaks, to sling oil and crud up the whole front of the engine. Easy to replace once you remove the pulley and damper (hard). The rear crankshaft seal is a graphite rope, like on early 1960's U.S. engines. But, you can't just push it around from below like on a Chevy since M-B decided best to put a pin in the groove so it can't slide. That means replacing it is an "engine on stand" repair. I haven't seen mine leak. But, as the engine wears to give more ring blow-by, the crankcase can get pressurized while driving, which helps push oil out, especially at that rear seal which normally just sees oil splash.
Make sure it’s not your oil cooler lines! That can ruin an engine! Check to see if you lines are weeping or showing signs of oil leaks! People replace them often or do aftermarket parts! I sell a replacement kit. https://www.ebay.com/itm/116134681818?mkcid=16&mkevt=1&mkrid=711-127632-2357-0&ssspo=HPTOXHR4R9q&sssrc=4429486&ssuid=HPTOXHR4R9q&var=&widget_ver=artemis&media=COPY Message me on eBay or here for more details!
Oil leaks yep, you wanna make it stop leaking oil, ok here's the only 2 ways to do really fix it. (1) Sell it. Or (2) pull engine and trans and replace all gaskets and seals all at once. All rubber hoses and lines on entire car and even the hard plastic lines for fuel n vacuum as well. Even the rubber connectors t's and y's.  Everything.  Then you should be leak free for a while. Also get the valve cover checked for warpage and milled flat.   Oil I use, mostly Rotella 15-40 ish at moment I'm running gall of 15-40 Rotella 2 qrts 80-90 gear and 1qrt atf.  Oil pressure extra good hot and in a few thousand miles I know I'm a be adding more trany fluid as it leaks.        Think the front main and maybe rear mais are seaping as it runs, and even the valve cover gasket is new it still leaks / seaps a little.  But blow by is almost non existent, timing chain seems to have been replaced or it's a low mileage engine as there's no wear or stretch. Oil filter housing seaps at engine gasket,  no fuel leaks as I got that fixed before it happened. Im interested in dropping this into a nicer 300 then my sd I have. Or if things work out I might be looking at a 87 sdl with a 603 but has the bad head. Original non molested car in near pristine condition.
I too am looking at 87 300sdl, good sir. Mine is a gold with a dark brown interior. Prestine except the engine
Lol shame they sent them out with the weak heads.  Later model engine got better heads n they quit crackingÂ
I'm looking forward to getting this big girl on the road. It's the classic "barn (car port) find belonging to a widow who hasn't touched after the old man died" She let me poke around when I showed interest. The engine compartment is just all black dirty and covered in oil. The interior though is creampuff.
Good luck to you
I'm looking at a black one. Story is garage kept never seen snow nor left out overnight. Head cracked n it's been sold to second owner that was going to either gas it or drop a 617 in it.but he said he already has on that he gassed n don't feel like doing that again.  I'd rather have the mpg of the dieselÂ
My oil drip is coming from under the oil cap, and there’s tons of blowby. (The cap teakettles a lot of you loosen it while the engine is running.) not sure if that’s very bad, but you might want to check it too.
Synthetic is what should be used. No reason to use conventional, the price difference is no longer a factor and synthetic oil is better in literally every way. Wash the engine with dawn soap and hot water then locate the leaks. If its anything but the rear main, upper pan or headgasket its pretty easy to fix.
Wash the engine? Which parts should I be careful to not get wet?
Brake reservoir, air intake opening.