Hey guys I'm hoping you might be able to help me out, I'm working on my car and the current status is that I can't start it after changing out the lower intake manifold gasket.
It's a 97 park avenue, basic, with a 3800 series 2 engine. I believe around the 75,000 mile mark (I'll have to double check to be sure, but it's something close to that.)
I'll fill you in with a little back story. About a month ago there was some coolant slowly leaking. I couldn't figure out where since there were no puddles underneath the car. I looked around and saw that the previously replaced water pump had just a little bit of what looked like dried and burnt coolant around it. After taking it off it still seemed to work just fine and I resealed it with a new gasket. I flushed it with the hose, ran it, and drained it. I put in about a gallon of premixed coolant into the radiator and about another half in the reservoir. I ran it and had to get going to work, drove it and about 3 miles in the temp gauge kept climbing. I pulled over let it cool off, topped of the radiator which was not very warm and kept going. About a mile later the gauge kept climbing and I stopped and did it again, but this time after restarting it droved very rough and felt like I lost a cylinder. another mile later, it I stopped and once more I topped it off, but this time I couldn't restart it. I noticed that the inside of the radiator was very warm as I saw a little steam come out as I refilled it, but the cap was cool, and it didn't draw from the reservoir even though I made sure it was very patent when I flush and cleaned it out. ( maybe a loss of vaccum to draw it in?)
I had it towed back to my house and pulled the spark plugs. Fresh coolant shot out of cylinders 3 and 5 (closer to the front and throttle.)
I let them dry, put them back in there and tried again. with about 2-3 seconds it tried for a second and then sounded like it ceased. I pulled them again and this time cylinders 1 and 3 were flooded with coolant, this after only about 3 seconds of the starter trying.
I did a little research and found a few different possibilities for that to happen. Of which including heads/ gasket failure, intake and manifold/ gasket failure of upper and/or lower. I looked more and it sounded more and more like the intake was what was causing the trouble.
I get an estimate for the job and it's easily over 2 grand, so I decide to do it myself. I start by taking it apart. First the plugs, and the wires and etc.I take off the intake manifold and there's a nice puddle of coolant just sitting there. I clean that out, inspect the plastic manifold, nothing really stands out... so I go deeper. I pull off the intake. low and behold the two lower intake manifold gaskets are in pretty bad shape, with seals bowed in, a little bit of cracking and coolant sitting in cylinders 3 and 5 with the rest pretty clean and dry. I get a new set of LIM gaskets and put them in, with a little dab of RTV sealant at the joints and carefully put the aluminum intake back on with a new coolant temp sensor on it. With the plugs still out and the wires disconnected from the plugs I cranked it for about 10 seconds to remove the coolant I couldn't reach that was siting in the cylinders. I torqued the intake bolts in sequence, and the same thing with the plastic upper intake manifold( with new main seal on the upper as well to be sure). I put everything back the way it went, with new plugs, wires and air filter, cleaned the throttle body out with some break cleaner, cleaned up the pcv valve and hooked up all the wires, vacuum hoses, fuel lines... everything. I go to start it and it doesn't want to start. It does cycle but there's no real firing going on. I look the thing over and it turns out I think I swapped the cylinder 2 and 6 spark plug wires. I try again, still no luck. a little frustracted I pull the plugs, look them over and they are a little wet with gasoline. Each one looks like it was flooded a little bit, to the point I could whip the spark plug with my hand and a few drops of gas would fly out and hit the floor.
with them out I figure maybe the fuel rail needs to be primed so it's shooting evenly into the cylinders. I cycle it for about 10 seconds.
I let them dry, put them back in and plug everything in... still no luck. I think to myself," okay there's fuel, air...maybe there's no spark...". so I pull them one more time, line them up, have my brother crank it for about 2 seconds and I see sparks from each one.
So I have fuel, spark and air, but it still won't start. It's not ceased otherwise I wouldn't have been able to cycle out the coolant and well, it wouldn't cycle in trying to start.
when I try starting it I have noticed that there is some firing going on, but it didn't seem very continuous or in sequence. I looked the plugs over and still everything is as it should be, so I'm really lost at this point of what it could be.
Is there something else timing related that would have been thrown out of tune with these part being moved around or coolant having been in the system...?
Any and all advice at this point would be greatly appreciated. this is the first time I've done an engine repair of this magnitude and I want to figure out what I missed so I can get this thing running great again.
thanks guys!
-John