Hey ya'll, I'm a new member. Just bought a beautiful '99 Deville with 120,000 miles for 2 grand. Was previous owners mother's car. It is losing coolant, but not leaking. He replaced the radiator and the water pump. Runs and drives great, but will only go 6-7 miles before low coolant light comes on and you have to add water.Looks like head gasket problems. Took to local mechanic today, will see what he says. Can't decide whether to replace head gaskets and time -sert block or replace engine. If I replace engine, figured I'd go with the 9 code engine instead of the present Y code. Previously owned a '97 Deville Concours and she was great. Any thoughts?

You cannot swap engines. Different PCM's & trans final drive ratio's. Stick with the "Y".

Heard from mechanic today. He removed the radiator and flow tested it [checked out o.k.], he replaced the water pump, but no change. He determined the head gasket is probably blown as suspected. He does not do this procedure but knows another shop that does for $1500.00. He says the guy is backed up two weeks but he will get to it asap so I guess that is what I'll do.

Hey ya'll, I'm a new member. Just bought a beautiful '99 Deville with 120,000 miles for 2 grand. Was previous owners mother's car. It is losing coolant, but not leaking. He replaced the radiator and the water pump. Runs and drives great, but will only go 6-7 miles before low coolant light comes on and you have to add water.Looks like head gasket problems. Took to local mechanic today, will see what he says. Can't decide whether to replace head gaskets and time -sert block or replace engine. If I replace engine, figured I'd go with the 9 code engine instead of the present Y code. Previously owned a '97 Deville Concours and she was great. Any thoughts?
~ Hey Doc: These are woth a look.
Thermaweld
SteelSeal
Thermagasket
http://www.rxauto.com/
Skullman {:{}

dude... FIRST try BARS LEAKS heavy duty radiator stop leak.... its REQUIRED in most caddy engines.... give it a try before you drop 1.5 g's into something that could most likely be resolved by a less then 5 buck bottle of stuff.

dude... FIRST try BARS LEAKS heavy duty radiator stop leak.... its REQUIRED in most caddy engines.... give it a try before you drop 1.5 g's into something that could most likely be resolved by a less then 5 buck bottle of stuff.

"Heavy duty radiator stop leak" is not the factory "required" suppliment. It is product HDC or the powdered version G12BP as seen below, but it will not seal a bad head gasket.
http://www.barsleaks.net/products.html#Cooling%20System%20Products

Thanks for the replies guys. I did try the Bar's Leaks before taking to mechanic but it didn't do any good. Since I may keep the car awhile I want to know it is fixed properly. The mechanic that does these is getting the car tomorrow so I'll see what he says.

Here's an update. Talked to new mechanic today. He has done many of these cars"more than his share". For 1500.00 he will remove engine, remove heads, install time-serts , check and mill heads, replace heads and while engine is out replace all gaskets and seals in lower half of engine with new updated gaskets. He informs me that the original gaskets were too small and caused a lot of leaks so there is a new version that solves this. All work is guaranteed and will take approx. a week. Almost sounds too good to be true! Will update when work is completed.

Finally, an update. Got the car back yesterday from the repair shop. The place looked like crap but the guy knows what he's doing. For 1500.00 they pulled the engine from the top {that's how this guy does it}, removed the heads, had them checked and milled, installed timeserts, replaced heads,replaced case-half seals, rear main seal, front cover seal, water crossover seals, oil pump pickup, and put it all back together. Runs great, no more water loss and over-heating. I am very pleased with the work and the car. Will probably keep it a few months then sell it and get another or something else. My wife always complains that we have too many cars, but I love 'em.

Congrats!
Thats a great deal on the car and the timesert job!