HELP! What is wrong with my car?

Hi,

I desperately need help in figuring out what the hell is wrong with my car.

To start:

I have a 4.6L 1998 Mercury Grand Marquis. I bought it with 107,000 miles on it in January - it was an Arizona car (snowbird) - but I live in Minnesota. The car was perfect when I bought it - had it checked over. Only recommendation was that I do a general tune-up because the car had hit that point in it's life where it was needed (mileage wise). I replaced the crappy coilpacks, bad sparkplugs, all fluids and filters, etc.

The care ran smooth. We noticed that there was an itty bitty leak on the intake manifold from the front (Left side if you are looking under the hood). I was told I could drive it around and that it would be fine until summer came.

However, starting about 3 weeks ago the temperature gauge just shot up - but immediately shot back down, and the check engine light when on. I pulled over right away and called my fiance at work (he is a tech at Tires Plus). He came home and ran a code reader - turned out I needed a new thermostat. Replaced it. All was well. I did notice that after that the temperature gauge always floated just barely above C on the dial.

Then... I came back from vacation last Monday and I picked up my car from my parents. Nothing was wrong. The very next day it was running like 'a bag of ass' - I was out doing errands and the car was running real rough - shaking terribly, blowing white smoke out of the exhaust(not blue or black) and the check engine started flashing (it never stayed on just flashed on and off). I went straight home and called my fiance, and he ran a code reader again. I was misfiring on 3 cyilnders only.

Weird. We checked coolant and oil - they were perfect. Levels weren't down and colors were clear. It was clear at that point that the intake manifold needed to be replaced (figured thats where the white smoke came from).

So, on Friday, Monday, and today (we have an open garage and it's been rainy/snowy so we had to close up shop each day) both my fiance and I replaced the manifold. It was just shit where the leak was at - all gunky. Anyways, we put a new intake manifold on and put everything back together. We started her up and still running a little poopy! Drive it down the block and back and it's not shaking anymore...but the temp gauge isn't working, there is still white smoke and PC340 popped up ....

I'm super sad, because this car is my baby, and I've been doing research and everyone says it's a head gasket. But my fiance is dead sure it's not blown, maybe a small crack; because everything else looked beautiful besides that damn leak on the intake.

Any ideas on what could still be causing the white smoke- when the car is running smooth now? And that code - it wasn't there before we unplugged the battery? Also, why is the temp gauge not working?

Any help would be great. Sorry for the long winded post. :)

I'm sure you double checked to make sure the sensor was connected, did you bleed air out the cooling system? how long did you operate the engine after repairs could there be some residule coolent in the exhaust? Generally leaking head gaskets or a cracked head will put antifreeze in the crankcase. you could pull the spark plugs and inspect them, one extreamly clean(steam cleaned) might indicate antifreeze in the combustion chamber,i have some actually emit steam out the plug hole. you mentioned you had it tuned up did they replace the plug boots along with the plugs? that is normally what should be done if not the engine will misfire. i haven't reasearched the code but you can google it .

We actually replaced the spark plugs when we put in the new intake because there was coolant on them but that was the leaking intake causing that (or so I was told). Every sensor has been double checked, and all are connected correctly. We thought the exhaust would emit white smoke for a while (residual gunk running thru) - but it never stopped; maybe we'll run it more only ran it for 15mins). It's not running rough just the smoke, cam sensor & temp gauge not workin'. Is it possible that the cam could cause some symptoms if it's faulty?

Since you have two sensors with issues I would inspect the connectors for corrosion, you ned to check your cam shaft sensor for proper operation and voltatge. also double check that all ground wires are attached and tight, a loose power ground wire will cause many different driveability problems.

Thanks for the info guys!!...had similar problem! Info helped!! no credit check catalogue (http://www.cataloguesnocreditcheck.co)