Your question seems to be of particular interest right now. All older cars with untouched engines can have head gasket failure do to nothing more than age. The heat cycle can and will destroy the gasket over time. The harder you drive the car the greater the chance that something will break and it always happens at high speed for prolonged periods.
The death rattle:
strange sound like pinging at higher engine speed or just normal engine speed that lasts for a few minuets and then seems to go away. You may never hear it again but the engine will use oil and likely smoke after this. At idle or low engine speeds the noise will be LOUD and you would likely shut it off.
This is a piece of broken piston ring bouncing around in the cumbstion chamber. It will eventually get stuck into the top of the piston or cumbustion chamber. It makes a mess but it usually repairable. The cylinder wall will be heavily scored but it's already worn well past the normal limits anyway.
Head gasket failure:
age, improper installation, over heating, warped block or head will and can cause this. Always check the parting surface of the block. I've pretty much gone to having a very light cut made to true up the surface. This usually only needs to be done once and not every time the head is off. If you want more compression deck the block and NEVER the head.
Regardless of all these things if you run your engine out of coolant it will warp everything. Usually the gasket will blow out. No coolant means you usually won't get any in the engine depending on where the leak started.
There are two types of gasket failures; wet blow and dry blow. A dry blow failure will just go to the next cylinder as a compression loss. Early engines are more likely to do this.
A wet blow will have coolant leak into the cylinder and into your oil pan. 280SL is more likely to have this hapen due to how close the cylinder are to each other and the milled slot between each cylinder.
A cracked head or a leak into the cooling system will cause a sudden rise or temp spike that won't cool down. The rad may be constantly empty every time you check it, yet there seems to be no leaks.
If you think you have a slow leak you may be able to find it with a leak down test. Always remove the rad cap during this test. You can take a small sample of oil and have it tested which will tell you if you have anti freeze in your oil - even trace amounts.
How hard can you drive these cars? That depends on how good the engine is. Damage always happens at high RPM's and it's permanent. How deep are your pockets?
These cars DO have limitations just like any other car. Probably higher for they're time period than many others but they will only go so fast, come to a stop only so quickly, corner only so fast be driven only so hard. New parts and rebuilds should bring the car back up to as new standards while modern lubricants will greatly improve componet life.
If you want to take your car outside of the stock configuration realm then you enter a diffent forum. Even a CD radio is considered sinfull by some. Drop a 6.3 into your 280SL and it's a sreet rod - a German street rod.
I believe that the Pagoda Group understands that there are people out there who may wish to do such things but our primary focus and mandate is to preserve the heritage of the 113 SL while understanding that some may want to change or upgrade their cars. This is, of course, up to the owner.
So, I've talked to the board and presented the idea that we have a new discussion area on this site called R&D (research & development ) This will be a sub heading of the main forum to discuss such things as engine modification/ replacement ( 5 liter anyone? ) brake upgrades, possibly springs or suspension or anything that falls well outside of stock repairs or parts.
If this is your calling this will be a great addition for you. If you have little interest in such things you may not go there but all would be welcomed.
This will be run by the administrators ( not me ) should we decide to do this ( it looks like a go though )
Any input on this idea would be welcomed.
Dan Caron's
SL Barn
benzbarn@ebtech.net
slbarn.mbz.org
