Consensus on rebuild
 

I have a 1991 190E (190k miles) with a blown head gasket. A head gasket, valve job and coolant flush will cost me $2400. Overall, the car is in very good body shape but it does have a lot of miles on it. Do I fix it and have virtually a new engine or do I look to replace it with one that's running. There are many 190s to pick from here in the Bay Area (SF) for the price of a rebuild.

Your third and least expensive option would be to replace the head gasket, unless it was overheated and rattled itself apart.

My take on it is to rebuild the engine.

You can replace your whole car with another one for the same dollar amount, but then you have a car with a lot of unknowns.

With your current vehicle, you at least know the maintenance record and what works / doesn't work.

hmm.. tough call..

if you have storage space... i would think about spending 3500 for another with much less miles... and storing the other one in a garage for parts.... or part it out..

i once parted out a 300e...and got a total of 2200 out of it... pain in the butt..but i also kept some parts for my current fleet...

just a thought.

if the car is not using excessive oil just replace the head gasket and do a valve job. the bottom end is probably good for 300k more.

tom w

t'was clean
 

Thanks for the input. I'm assuming this to be a head gasket considering the amount of oily goo in the expansion tank. Somehow a black sludge poured through the exp tank cap down the side. This is something that popped up in the past week because I check all fluids on a regular weekly basis. I had a coolant system flush six months ago because the level sensor had corroded badly from the prior use of lousy coolant. My mechanic, also a dismantler, claims that non-Mercedes coolant is a major culprit in heads going bad.
My wife drives the car daily to work. The car smogged extremely clean a couple months ago. Oil barely shows dirt after 3000 miles, when I change it. I took the car on a short drive and oil press was 3 bars and the car didn't heat up past 80c. I didn't detect coolant on the dip stick. I actually would store the car and save it for later but oil in coolant hoses is not good.

I agree with Tom about just doing a head job, which would run you only $1,000 -$1,200.

The bottom ends on any Mercedes engine virtually never wear out.

I'd replace the valve guides and seals, a new headgasket and button it up.

Be sure to do a really good coolant flush afterwards to get all that stuff out of your heater system.

Is it possible?
 

I hate to back up here but I'm thinking if it's possible that the sludge in the ext tank is from the radiator and that maybe this whole thing is only circulating from the radiator through the cooling system. I really can't tell if the sludge is oil or gunk but it's greenish black. If the engine was burning oil to produce the gunk in the ext tank wouldn't there be some evidence on the dipstick, which shows relatively clean oil without any burn residue? My mechanic seemed to want to jump right in on the valve job, citing the number of miles as the reason, even though the car probably consumed 1/2 quart of oil over 3000 miles intervals. Maybe the coolant flush of the green coolant a few months back missed some residue. Thanks again for the responses. I've talked to two different shops over the phone and they're both ready to go treasure hunting, it seems to me.

i think possibly you might not have even a bad head gasket.

i would try flushing it out first. this could be residue from the wrong antifreeze. the pushing it out of the tank could be just from a bad rad cap, perhaps. you don't sound as if you have any other symptoms pointing to a bad head gasket.

your mechanic might be a bit too eager in this case.

tom w

Probably not a bad head gasket. Just flush it well while the AC heater is running. I wouldn't even worry about it till I see capuccino in the expansion tank.

The 1988 & later 2.3's did have oil/coolant head gasket issues at cylinder #4.

Unless you are having other problems like oil consumption, I would consider only the head gasket. Going rate should be 7-8 hrs & parts $200-300