hello,
have a bit of a delima. my car has several problems that i would like to address. #1. poor exceleration, #2 oil leak, #3 drastic sudden drop in gas milage. i went from a consistant 250 miles per tank to just 180 miles in 2 tanks.the gap on the plugs was horrable,050, and the o2 sensor was definatly from 92.even after changing plugs, bosch w/ proper gap, and o2 sensor , bosch i am only up to 225-230 a tank., #4 milkshake in coolant overflow( just changed oil and no coolant in oil, radiator is brand new(nissens) and the system has been flushed multiple times. the history on the car is this: it was a toy for super rich old lady who never drove it, i got it w/ 19k in 2000. 15-18 mos ago the caR went in for a new head gasket. it was slightly warped(.003)so i had it shaved(.007) and new valve guide seals put in. 4 to 5 mos after the gasket was put on a milkshake appeared in the coolant overflow for the 1st time. before the head gasket was replaced their was never a milkshake, and yes i know it needed a new gasket i took it to 4 differnt shops. i had it flushed. the milkshake has come back in some way shape or form since then. the car was in a minor fender bender( front end) which is what caused the radiator to leak. i also thought perhaps it could have been trans fluid not oil mixing w./ the coolant, so it was replaced and the coolant system flushed 3 times @ operating temp w/ the heat on. the shake came back, but not as bad. i did a compression test cylinders 1,2,5,6 came back w/ 150 lbs =/- 2 lbs, cylenders 3,4 came back 90 and 105 respectivally. my delima is this i have put to much money in to the car to sell it( plus the body is still pretty tight), the guy that did the head is a trusted respected mechanic. he said he will warranty the head gasket(even though it is out of the 12/12k warranty he gave me on the job).no charge no problem. its a 12 hr job and his labor rate is $70 per hr. the problem is that it could be a cracked block or head too. if its one of them i owe him at least 420$ and my car still needs to be put back together. i can get a used engine from a reputable source w/ 85k on it - the fuel distributer, trans and oil pans, and pulleys for 600 $ delivered. even though its a 20+ hr job i could pull it out w/ a more experienced friend, take what i need and put it on the new one and drop it back in, and get it done in 2 weekends. i even have somewhere to do it w/ a 1/2 ton ele rolling hoist. the BIG question is do i roll the dice and hope its the gasket and it wont cost me a dime or do i shell out the 600 + 300 for friends help, and 2 weekends of my time to swap engines. if i do the swap i will probally have the trans freshened up while its easy( i plan on keeping the car of a while).even if i have my guy take it apart hoping its the head gasket and its only a cracked head i will be out 12 hrs @ 70 bucks a pop + the cost of the head. if its the head or block and i want to swap it myself i will be out 6 hrs labor, probally slightly discounted, 90 bucks for a tow, and a rental untill i can get it done. it would take a week to 10 days for the engine to get to me, assuming that he still has the same one or one that i like. one additional detail the car did have a new water pump put on about 5 months ago( well after the shake appeared)and the car never got to hot. it got to 104 deg C when the water pump went bad and i had it towed are there any other tests that i can do to eliminate a cracked head block/ head or to confirm that it is a bad gasket????? is there any point in doing a leak down test? that will only tell me if its a cracked head or bad gasket right? any opinions on which way to go??? thanks

Perhaps you could let us know which model Mercedes you are driving.

Stop trying to treat the symptom and not the cause of the "milkshake", have the mechanic remove the head and test for head gasket, cracket head or block, have that fixed and it sounds like the rest of the car is in good shape.

__________________
Jerry

2004 SL500 Black 55K Miles
2002 s500 Black 90K Miles
1986 300E Gold 233K Miles
1966 Twin Cessna 320D
1989 Jeep Cherokee 233K Miles
1994 Ford Van E150 399K Miles

sorry its a 190 e 2.6 1992