Hello All...Newbie here. In February I purchased a 2001 Grand Marquis w/114K miles. The car would surge every now and then and the CEL was on so I had that checked and the code P0401 for the EGR come up. We replaced EGR with a new one. CEL came back on after a bit. I wanted my new purchase to have new plugs and Coils put on. Still no significant difference in power after doing that. After a month I noticed coolant coming out of the housing to where the thermostat is...it was cracked. I had the intake manifold replaced and was told the new intake came with a new thermostat and that was replaced too. Coil #4 was also replaced. Since then I hear what seems to sound like valves ticking and some whining noise from the engine but not sure exactly where from. My mechanic just says it could be a sensor. I'm not happy with that. This noise can get worse while accelerating. Now, I find that while running the A/C when 90 degrees out it will blow warm and the temp light will come on and the temp gauge goes way up to "overheating". I put on the heat and the gauge automatically goes back down and the car starts to sputter. I believe I read that the car is going through "failsafe" mode because I'm not leaking coolant at all. I am now throwing a code P1299 for Cylinder head sensor. Is it possible that I had gotten coolant where the plugs and coils go when the intake manifold cracked on me? And this is the cause of all this?
I just now found out that the person I had do the plugs and coils did not use any dielectric grease!

I've read through this forum but just can't seem to pinpoint my problem. Thanks for viewing and any advice you may have would be greatly appreciated.

KooK

If you get a P1299 it's overheating, period...

Sounds like it may be low on coolant, try running it with the nose elevated(will purge any air in system) and add coolant till it's full...

The noise you hear may be a loose spark plug or maybe broken exhaust manifold bolt, though in warmer weather states usually isn't a problem, generally a "northern thing"...

thanks for your response but I am not losing any coolant at all. But I will try running it with the nose elevated as mentioned.

I appreciate your reply to my post.

KooK

Sensors generally don't make ticking or whining noises.

For the ticking sound, you could you be hearing the fuel injectors. They are a bit chatty on this motor.

As to the whining sound that could be a bad power steering pump, bad idler pulley, or an issue with the transmission. You really need to localize it better...front, back, left, right, top, bottom?