new guy with car troubles

[mattgiroday]

Hello everybody,

I'm new here, and new to the Audi scene. I just got a 2003 Audi A4 Quattro 1.8t, however I am having some mechanical issues! My engine light is on, with the codes P0300 (random/multiple cylinder misfire), P0302+P0303 (cylinder 2+3 misfire), and P0118 (engine coolant temp sensor 1 circuit high). So I looked up what to do about these errors, and found out that ignition coils were the most likely culprit as far as misfires. So I went out and got new ignition coils and spark plugs for cylinders 2+3, and a new coolant temp sensor! The misfires are still occurring, however only when the engine is cold on startup (car rumbles, engine light flashes, and I experience a loss of power), and it pretty much goes away after I give er' some gas. Any thoughts on what else could be the problem causing these misfires? Also, now every time I drive the temp sensor randomly goes up to 130 C' once, and the coolant warning comes up. Shortly after that however, the gauge goes back to 90 degrees celsius, and it doesn't happen again. I find that the gauge flares up to 130 when I am experiencing a loss of power during driving (like if I am starting to go up a hill). It is pretty random. Any thoughts on what is causing these problems? Any advice is greatly appreciated! :)

Thank you,

Matt

[jjvwg]

Sounds like a bad head gasket and/or cracked head. Did you continue to drive the car when the temp gauge went up beyond normal operating temp?

[MacFady]

Are your misfires still occuring on the same cylinders now or are they random? If the same cylinders have you tried moving coils around to see if it changes cylinders or remains the same? Any oil/coolant mixing? What did the plugs you changed look like when you took them out?

[blitz2190]

Bleed the coolant system of air, then check the wires going to your coils. If you have no mysterious coolant or oil loss your head gasket is most likely fine

[blitz2190]

double post*

[Furly]

x2 on cylinder head leaking into the engine.

pull the spark plugs out and look inside with flashlight. if you see some of the pistons are black and some are steam cleaned, there's your problem.

we see these kind of threads every week.

[WB650]

As Furly can attest to with my car, keep an eye on the coolant level.

I started to get cold start misfires randomly last September...by December I was getting cooling system failures then my car became undriveable at the end of January and was in the shop getting a new cylinder head b/c it was cracked.

Also, I shouldn't the temp gauge be related to the Thermostat being fault. Maybe its getting stuck open?