Bad head gasket, how long can I drive it?
 

As sort of a continuation of a prior post. Thermostat stuck, car overheated, replaced thermostat. My benz guy says drive it for a while and see what happens before pulling heads.

Well what is happening is that while the oil looks OK there is definetley water getting into the oil (I see no evidence of oil in water). Huge cloud of white smoke when I start it. Drives fine though. Doesn't overheat. I'm losing about an inch of coolant as measured in the resevoir every 200 miles.

I'm OK just filling the resivoir regurally but am worried about more substantial damage. Like hydrolocking the engine, scoring the cylinders, damaging rings ect.

What are my long term prospects here?

TIA

Any idea of what kind of car it is?

sorry, 80 300SD 118k

Don't go too long
 

I had a bad experience doing that. What can happen is the leak into the cylinder gets worse until your Stanley Steamer experiences "hydro Lock" in other words the cylinder fills up with coolant, which does not compress. This causes the engine to sieze, bending important things, very bad. I was actually on my way to a repair shop when it happened, saving on towing, you know. It was a "K car", so I probably did the world a favor anyway.

If the car is worth a head job, do it.

Re: Bad head gasket, how long can I drive it?
 

Hate to say it, but the head NEEDS to come off. Water in the oil can cause FAR more damage than just a blown head gasket. Coolant does not lube at all like oil and can quickly cause lots of metal-to-metal wear. The huge white cloud of smoke (Really steam, but might just be unburnt diesel) does mean you are getting coolant in your cylinders. Not only does this not lube but it, can create hydrolock if the cylinder is stopped on the compression stroke, and rust the unprotected metal of the cylinders/pistions.

It may drive fine, but every mililiter of water getting into the oil WILL cause damage. Park it NOW and get someone to replace that head gasket and have a look around while the heads off (Surface damage, cylinder scoring, deck flatness, cracks, etc.)

I've got to agree. A little coolant out the exhaust is a gamble that you ought not to play very long. Coolant in the oil (look for some muddy color in the oil, or better still drain it and look for water) is a whole 'nother story and close to instant bearing death if you keep driving it. Be VERY sure you aren't getting water in the oil.

Coolant is also heavier than oil - so it accumulates in bottom of sump and at bottom of galleries it passes through.

I once bought a bargain car 220Sb knowing the head gasket was blown...... repaired the cylinder head but crankshaft main bearings were played (extremely rare) on account of coolant running through the system.

Thanks all, that's sorta what I figured. Time to break out the checkbook.