Yep....I finally got my head off of the 91 SDL I aquired. Number 4 and 5 cylinder has a crack in bettween the valve and glow plug! Oh well, what to do now? The engine has 250k No rod bending yet! Should I just junk the whole engine, or just put a new head on it? If I could find a decent used head, I would just drop it on and cross my fingers! So HELP!!

How deep is your wallet...My suggestion is now that you have the head off the car, cost out the repair costs. Verify that you have no rod bending and check the ridge at the top of the cylinder walls...measure the wear. If it burns no oil now, I' say go for the used or rebuilt head.

Check out the link below to Metric...They have re-manufactured heads. They're a bit pricey on the long blocks.

http://www.mercedesengines.net/categories.asp?cat=17

Here's an interesting site..$2500 for one with the valves...although they have misspelled "bare"

http://www.autoshoppingcenter.com/rebuiltengines/mercedeshead2.html

If you do decide to find a new or rebuilt head, check out this bulletin about the headbolts...

http://www.rebuiltautoengines.com/mercedes-articles.html

My first choice would be a used head from a low mileage car. My guess is that it would be the least costly. New heads don't come with the ancillary items. You will need to install all of the missing parts and you really won't want to bolt old parts to that shinier new head. The new head and all new parts would make you feel the best everywhere but your wallet.

I rebuilt a head on a high mileage 240D, and the only thing I didn't replace was the casting.,

Check this site...I've used this often to find who has the parts and how far away they are from you.

http://car-part.com/

Keep us posted...I have a 603 engine too!

The Tenor Man

__________________
Currently Driving.....
1987 Mercedes Benz 300D Turbo - Daily Driver.
2004 Buick Rendezvous...Smaller than it looks!
2005 Mitsubishi Galant - Not bad for a tin box...Lousey Seats
Past Vehicles.....
1994 Dodge B-250 Van- GAS HOG..Succumbed to rust!
1989 Mercedes Benz 260E - Totaled but no one injured.
1977 Mercedes Benz 240D - Loved it, but SLOWWW! - Succumbed to RUST!
1976 Mercedes Benz 240D - Same as above! -
1975 Mercedes Benz 240D - Same as above!

I think I want a used head option!! The engine looks good, I think just the head is toast. If I could find a used head, I would be in business!

Ok, i have a 617a engine around the house! Would it be crazy to install this engine?

If you were going to keep the car until it goes to the boneyard...it would probably work, but it would take a long time to work out the bugs.

You'd never have to worry about having to get a speeding ticket!

If you don't need the car, you can have lots of fun searching for a good used head...

The Tenor Man

__________________
Currently Driving.....
1987 Mercedes Benz 300D Turbo - Daily Driver.
2004 Buick Rendezvous...Smaller than it looks!
2005 Mitsubishi Galant - Not bad for a tin box...Lousey Seats
Past Vehicles.....
1994 Dodge B-250 Van- GAS HOG..Succumbed to rust!
1989 Mercedes Benz 260E - Totaled but no one injured.
1977 Mercedes Benz 240D - Loved it, but SLOWWW! - Succumbed to RUST!
1976 Mercedes Benz 240D - Same as above! -
1975 Mercedes Benz 240D - Same as above!

Need is relative! LOL! I have 2 gas guzzling Land Rovers that I drive!! Well I will just take my time, when one appears I will go after it! Thanks!

Is a new head out of the question? What do they cost now, $1700-1800?

Sixto
87 300D

Right now...yes! I don't have pockets that deep!

And thats bare, not loaded. Assume this one is iron, not alum like mine. Otherwise it could be welded.

Dumb question but how did this happen? What causes a head or block to crack? Is it just a function of old coolant or just 'age'?

__________________
Jennifer
90 350sdl

Most common cause of head crack-age is running the car HOT.

so why does it run hot? broken thermostat or old coolant?

__________________
Jennifer
90 350sdl

The car has 250k on it! The car ran hot, and the head gasket went! There is oil all in the water, but no water in the oil! I thought it would just need a head gasket replaced, but when I pulled the head I could see cracks inbetween the valve seat, and the glow plug! The car actually started and ran! I drove it up to the car dolly, and drove it back off! I do know some great aluminium welders, but I don't think it's worth trying!

Welding a head is only a temporary fix. Usually done when you dont want to keep the car, just enough to sell the problem to somebody else. Un ethical in my opinion. Might last as much as 5 to 10 thousand miles. If you buy a used head look fo patches of discolored metal. A patch usually has inconsist texture such as tiny air bubbles in the metal and a dark ring around it. Avoid these heads. Have a good machine shop look it over before you install. Have a pressure test done as well. The market is very strong for these cylinder heads and there is plenty of opportunity for a crooked used parts dealer to make great money off these patched heads.

Flywulf

Could be any number of things. Bad T-stat (though they usually fail in the open position), bad fan clutch, not changing coolant regularly (or at all ), blocked radiator, or burst radiator hose. I think those are most of the usual suspects.