'97 A/C Evaporator removal question

[decollect]

G'morning all. Replaced the compressor, accumulator, and orifice tube on my 3.1 Lumina after the compressor clutch grenaded. Figured it was 8 yrs old, might as well spring for the extra parts instead of just replacement clutch. It held vacuum just fine and accepted 30 oz's of 134. However it only cools when the car is moving. Mechanic said I have blockage in Evaporator. Says when the car isn't moving, because of blockage, the condensor is running too hot, so when the Freon finally gets to the evaporator, it can't cool down enough because the blockage in the evaporator doesn't let the freon out fast enough to get cold enough. When there is air moving past the condensor, it cools it off JUST enough to do it's job. I have to agree with this assessment as when stopped, it blows 65 degrees, but if you get it on the road for more than 5 minutes, it runs all the way down to 37 degrees at the center vent.

Question: How much of a pain in the A$$ is it to pull down the heater core and evaporator. Have Haynes book that says it IS do-able. I've been under the dash before, installing a stereo, but that's as far as I went. Any weird things I should look out for?

Thanks

[cadgear]

Its a lot of work but yes, doable. You'll do good to drain the cooling system, or at least have a lot of plastic sheeting and a drainpan. Haynes is pretty accurate in the step-by-step aspect, just take your time and don't try to force things. Its a lot more involved than a stereo, that's for sure..

[decollect]

hehehe yah, I have NO doubt that it will be a touch trickier than stereo. And to add insult to injury, apparently the blockage has gotten worse, as now there's NO cool air coming out, though the compressor is still kicking on. I get no cold flow back to the compressor.
And yeah, Haynes did say drain the coolant. Oh well, time for a drain and flush on that as well, anyway.
By the by, approximately what mileage can I start anticipating the intake gaskets to cut loose? She's got 52k on her now. Any way to prevent/forestall the "inevitable intake gasket sucking coolant" malady?

[cadgear]

Unfortunately, no. New coolant has new corrosion inhibitors, new aluminum sealant, and new problems with it. While personally I can't say when it might go, its usually between 50k and 100k. I replaced mine earlier this year, in Feb, at I think 72k. It might last you through 150k, or it might start going tomorrow. I think its the repeated expansion and contraction that is the ultimate culprit (well, bad gasket design too), so if you have a lot of short-trip miles it would seem to go earlier.

Its not neccesary to drain all of the coolant; if you unhook the heater core hoses from the firewall and plug them, you won't have to drain the whole system. But if its 1997, then yeah, you're three years overdue for a system flush. Might as well go ahead and knock that out.

[decollect]

I'm gonna hazard a guess that it's been done, but since I cannot be CERTAIN, will go ahead and pinch for it. Hey da wife and teen-agers ride/drive the car, don't want it going kaflooey. The car is former police unit, but had no lights. Best as I can find, some municipality around PA or NY. Usually (unless they're a REALLY poor district) the maintenance is kept up pretty good. Oil's usually changed every 2-300 gallons used, etc. This particular one looked like was used by a commander or something, again, no lights or antenna holes, but wired for computer, has the suspension mods, etc. Lastly, I think she was run off the road on the passenger side before I got her. Tranny pan is concaved in about 1/4 inch (nothing major) there's a few scrapes on the RH control arm and frame rail, just a little hint of looseness in the right suspension and a bit more torque steer than usual. I'm sure within 20k I'll be addressing the front end, but that will resolve the tiny noises I'm hearing on that side compared to the other side, and it will resolve some of the torque steer.
Thanks for da help, Cad.

[decollect]

ps, though the RH side kicks up just the barest bit more noise on bumps than the LH, they did put her back together pretty darn straight. As long as you're not inducing torque steer (on the gas hard), it will drive straight as an arrow. After now some 8k of driving it since bought the front tires are dead bang perfect even wear. Not gonna worry 'bout the front end for a bit at this point.