My 85' 380SE has 268K miles.... aside from the vac. leak- it runs well. However, since I have owned it- it has a slight knock or tap that can only be heard when the windows up/radio off between 1500-1800 rpms- under acceleration. I am pretty sure that it is the camshaft on the passenger side is the cause... I am sure it may be worn. It has 268K - still does NOT burn or leak one drop of oil between the 3-4K oil changes.

I have considered selling this car (getting PS leak fixed now), but since I have realized how poor the fuel mileage is on my truck I just bought- I have been thinking of maybe keeping the Benz for the good mileage I get with it- which is about 19-23 mpg in town vs. 13-16 mpg with my truck.

I know my timing chain may need replaced- I have no idea when it was last changed. I have been quoted about $500 to replace that. Maybe cheaper with another mechanic I may get a quote from- that is fixing the PS leak.

Now- about the camshaft.... will that probably take care of the slight knocking/lifter noise that I hear? Has anyone else had this problem and if so- what all was required to fox and how much $$$ are we looking at? If too much (more than I want to go) I will just not worry about it and drive it until it hits the road. Or I may sell it yet- to someone that knows about these cars and can work on them and give it the TLC it needs. I am not a DIY'er- so I cannot do as much to it as I would like. BUT someone that knows these cars and likes to tinker on them- could turn this in to a nice car. I think she has many more thousand miles left in her. I hate to let her go though... I love the style, the ride, the class, the features, etc.

I could always drop a low mile 3.0L turbo diesel out of a wrecked 81-85 300SD in it? Probably too much of a conversion though.

Any info on these engines appreciated.

Before replacing a camshaft or chain (recomended), I would look at the tensioner. At 260k you really ought to replace at least the chain and guides as well. The noise however may likely be the tensioner by your description.

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64 European Coupe Brilliant Silver with Red interior 4 Speed Sunroof
87 TDT 286k
87 SDL 195k
83 SD 202k
83 SD 201k
83 D 286k
02 R1150RT 32K
00 122HP FLSTF
07 KTM 250SX

"Danger takes many forms"

Chain, tensioner, and guides are not a huge expense if you DIY, and they will increase your confidence in the engine. Have you popped the valve cover to check out the cam? I just had mine off the other day (same car - 85 380SE) to replace the oiler tube connectors and the valve cover gasket. Removing the valve cover takes all of 5 minutes.

As for the gas mileage, are you sure you are getting 19 to 23 around town? That seems nearly impossible. I am very militant about keeping records. I have a spreadsheet which, among other things, contains entries for every gas station fillup, including odometer readings, trip readings, number of gallons put in, grade, price per gallon, etc. On my 85 380SE which is in awesome mechanical condition, I average 16 mpg around town and 19 on the highway. There is almost nothing I can do around town to change that 16 mpg around town figure. If I turn on the A/C and drive like a maniac, I still get 16 mpg. Same thing if I turn the A/C off and drive like a granny - I still get 16 mpg, most likely due to the low end torque nature of a V8. I even have the original window sticker which gives EPA estimates of 16 city / 19 highway. And we all know how incredibly optimistic those EPA estimates are.

My 300E, which is pretty efficient, will never see 23 around town, and it is lighter and has more horsepower.

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08 W251 R350
97 W210 E320
91 W124 300E
86 W126 560SEL
85 W126 380SE Silver
85 W126 380SE Cranberry
79 W123 250
78 W123 280E
75 W114 280

Check it out, just a section of my log below. I have erased out the locations for privacy, but otherwise everything else is there. These are just a few out of hundreds of entries, and I do this for all my cars as I maintain them very well.

Actually, my last fillup lowered my average mileage to 15 mpg. And on this car I only average the last 15 fillups since I fill up about twice per week on average. I use a handheld GPS to monitor my actual mileage; if I went by the odometer I would actually only get 12 to 13 mpg since it is wildly inaccurate. I will be fixing it shortly.

I would like to know what you are putting in your tank in order to get 19 to 23 around town.

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08 W251 R350
97 W210 E320
91 W124 300E
86 W126 560SEL
85 W126 380SE Silver
85 W126 380SE Cranberry
79 W123 250
78 W123 280E
75 W114 280

gmerc, don't you see it? Your engine is not even broken in yet. Mileage always increases once the rings seat...

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64 European Coupe Brilliant Silver with Red interior 4 Speed Sunroof
87 TDT 286k
87 SDL 195k
83 SD 202k
83 SD 201k
83 D 286k
02 R1150RT 32K
00 122HP FLSTF
07 KTM 250SX

"Danger takes many forms"

Hello. Yes, I am sure I am (well, was) getting 19-20 in town.... easy driving mind you. That is why I love driving the car so, as opposed to my 2000 Toyota V8 truck- which gets about 14-16 mpg in town.

However, since the rough idle/running when the engine is cold and the occasional misfire, I have noticed that the mileage has declined, but it is still at least 17-18 in town.

About the chain/tensioner- I would LOVE to have those changed, as well as the oiling tubes as someone mentioned, but since the car has so many miles and I have so many cars already, I do not want to put a small fortune into this car. Chain/tensioner is going to be about $500 - not to mention $$$ for the rails/guides as well. DIY'er? That is something that I am not.... changing the oil, transmission fluid, adding antifreeze- changing bulbs- that is about it. Also, I do not think the knock noise is the tensioner, but I guess I could be wrong.... I have been before.

Hopefully the guy that is going to install the steering box seals will know what is causing the rough cold running.

Thanks again!