Hey guys. New MB owner.
I just bought a 1980 450SL and really love the car but having some problems and could use some advice.
1. There is an oil leak coming from the head bolt/rear main or maybe both. The headbolt is not accessible without removing the manifold so that's going to be a pain and of course the rear main is no fun at all. I have already had the valve cover gaskets replaced and it helped a little. After about 1500 miles of driving I had to add about 1/2 qt of oil. What should I do? is there any sourt of additive or anything I can do to keep from replacing these seals? Should I even worry about it? the oil pressure gauge is also pinned all the way up as long as I'm driving and goes down to about half way when I let off the gas (as long as the car is warm). It seems to be directly proportional to the RPM. What's the deal with that?

2. The car is extremely sluggish off the line especially when it's cold. It will hesitate and act like it's going to choke down then I hear what sounds like a small backfire coming from under the hood and it goes fine. Once it warms up it not a problem anymore (though still slugish if I try to happer it off the line).

Any suggestions?

thanks in advance.

I cant help with the tuning, but here is my advice on oil consumption: You are getting 1000 miles plus per quart and your complaining? A lot of new cars use more than that! Get your engine diagnized with a qualified m/b mechanic. As a new owner, you should start with right settings. Good luck, Abe G

Your oil pressure gauge readings sound normal, the needle should peg above idle and when hot should be around the mid point, i.e., about horzontal. Your leak may be due to other gaskets having shrunk over time. You might try snugging up the sump and cranckcase bolts, use care and do not over-tighten, just make sure nothing is loose. Thoroughly clean the engine top and bottom, some of your leak may be residual oil from the valve cover leak. One-half quart in 1,500 miles is not bad at all. An old friend and sage mechanic once told me that leaking a drop every 100 feet will add up to a quart in a 1,000 miles. Don't know if the math works out, but sounds like its a toss-up for you whether you are leaking more than your engine is burning. Also, remember that some oil always gets burned, if not, then something important is not getting lubricated.

Have your cold start and aux. air systems checked. If it runs OK when warm then they may be acting up. You also should check that all the vacuum hoses are tight and not leaking; vacuum leaks are very bad news and will cause all manner of problems that prevent good running on an otherwise fine engine.

Finally, the beastie may just need a good tune-up and some TLC from its new owner. I suggest giving it an affectionate nickname and always speaking nicely to it and about it when talking with friends. Cars are very perceptive creatures and can sense fear. When they do, your wallet is not safe...

Be of good cheer and welcome to the great society of SL owners.

230/8

Check the valve covers but my bet is you need new head gaskets.

Never seen a leaky rear main.

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Chas

Had a 380SL, 450SL, 380SEL, 420SEL, 500SEL

Got a Euro 500SEC right now.

Wow, that was quick!. Great Forum.

It sounds like you all agree for the most part that the oil leak is probably not worth the cost or repair. I just wish it wasn't leaking on the manifold where you can smell it every now and then.

In any case, about the sputtering and hesitation. The car fires right up every time I have a brand new Jeep that doesn't start up nearly as easily and seemingly effortlessly as this thing. Only when you hammer it right off the line??? How do I check the vacume hoses? Carb?
I have already replaced the air filter, fuel filter and distributor cap. No improvement.

Look for all of the little hard lines around the engine & give them a gentle finger wiggle. Hmmm. A squirt of aerosol carb cleaner on the lines will give you a surge in idle speed if it hits a leak. It's a good diagnosis tool.

Finger wiggle,

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Norm in NJ
Next oil change at 230,000miles

That car has CIS. I would suggest checking the little filter screen at the fuel distributer head. It can clog and cause poor performance.

Peter

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