P0300 - P0303 misfire detected

[yannla]

Hi,
Since I bought my 2004 PT Cruiser, I have this misfire problem (random + cylinder #3)
I took my car to the garage and of course the problem is still not resolved.
So I scanned the errors myself and this is what it returns to:
Does anyone can tell me if there is something wrong with the numbers.
I don't know how to read them...
One more thing, when it is very cold, like -25°c, I have to fully open the throttle to be able to start the engine. Otherwise it won't start.

***************
meta-info header:Error Codes
file version:1
type:5
time:1426960606756
name:Trouble Codes
codes:P0300,P0303,
codes_p:P0303,
codes_raw:486B1043030003030000​4C;;
codes_p_raw:486B1047030300000000AD;;
*****
Error Codes
P0300
Random/Multiple Cylinder Misfire Detected
Vehicle speed (Speed) 0 km/h
Intake air temperature (IAT) 0 °C
Long term fuel % trim Bank 1 (LTFT1) 0.0 %
Engine coolant temperature (ECT) 51 °C
Fuel system status (FSS) Closedloop:usingO2sensorforfue​lmix
Calculated engine load value (EngineLoad) 38.43 %
Timing advance (TA) 16.5 °
Engine RPM (RPM) 186 rpm
Short term fuel % trim Bank 1 (STFT1) -6.25 %
Throttle position (TP) 15.68 %
Intake manifold absolute pressure (MAP) 40.0 kPa

P0303
Cylinder 3 Misfire Detected

===================
Pending Codes
P0303
Cylinder 3 Misfire Detected

Raw values
Error Codes 486B10430300030300004C;;
Panding Codes 486B1047030300000000AD;;

[NitroPT]

P0000 codes are designed for values outside the set of rules for a normal DTC.

If you choose to do the Diagnostic work yourself you will need to start first re-set the DTCs and cycle the engine one time and recheck for the DTCs.

Your description of the start issue should yield other DTCs.



May I also suggest that you start a introduction thread and get welcomed to the forum. Some experienced members will be more receptive to helping you if some of feel you are here to become a regular member instead of just getting free advise on a single thread.

[yannla]

Nitro,

Right, I don't use to post on forum... I'm quite a newbie...
I have a PT cruiser 2004 2.4L turbo.
I don't have that much experience on PT cruiser since we bought it last year.
Except the rust and the misfire, the car runs great.
There is nothing I can really do for the rust, we have too much snow (and salt!) on the roads.
Fix the body is not a fair game in Quebec...
My project is to have a brand new color this summer, I'll post the pictures.
We use to have an 1989 mini cooper and what I can tell is, we have the same nice feeling of driving (comfort is not comparable )

Anyway, I always have this misfire issue.
It is not really a big deal, only the idle is a little bit low and I have these misfire codes.
For 6 months, we (me, my dad and the mechanic) are not able to fix.
I already spend $3000 on it for this problem:
- new: camshaft sensor, Timing belt, air filter, battery, intake manifold gasket (it was leaking)
- We also swapped the wires and spark plugs and re-set the DTCs... spark plugs looked good
- We gently sprayed a little bit of water on the top of the engine and nothing happen
I still have the same rough idle and misfire code P0300&P0303.

I have a couple of symptoms:
- When very cold, -25°C (rare), it is hard to start the engine. I have to open the throttle... weird !
Above -20°c the engine start correctly.
- When the fuel tank getting empty, the idle is better, around 850... weird again !
- whatever the temperature or the idle speed are, I can hear a constant misfire every 1.5s...

I would say this is not an electrical or a leak issue.
My best guess for now is fuel or/and compression problem... what do you think ?

[quicksilverdon]

You spent $3,000 and didn't see fit to put in new plugs and wires?

[ptcruisersteve]

More information would be great!
How many miles on the PT Cruiser?
Was a compression check done on the cylinders when the spark plugs were taken out and the gap checked?

[yannla]

Yes, $3000... no comment...
PT is about 100.000kms (62000miles)
We checked the wires with a multimeter, looks good.
We also checked the gap of the spark plugs (bosh, gap .50), looks good.

I did not check the compression yet. But regarding the codes P0303, I would focus on cylinder #3 and check the injector and compression.

I found a good article on this :
Part 1 -How to Test the Engine Compression (Chrysler 2.0L, 2.4L)

[ptcruisersteve]

Originally Posted by yannla

Yes, $3000... no comment...
PT is about 100.000kms (62000miles)
We checked the wires with a multimeter, looks good.
We also checked the gap of the spark plugs (bosh, gap .50), looks good.

I did not check the compression yet. But regarding the codes P0303, I would focus on cylinder #3 and check the injector and compression.

I found a good article on this :
Part 1 -How to Test the Engine Compression (Chrysler 2.0L, 2.4L)

Make sure you do the compression on all four cylinders. You need to know the compression on all four cylinders to see if there is a big difference enough between the cylinders or extremely low compression to cause the misfire.

[LionPT]

Originally Posted by yannla

Yes, $3000... no comment...
PT is about 100.000kms (62000miles)
We checked the wires with a multimeter, looks good.
We also checked the gap of the spark plugs (bosh, gap .50), looks good.

I did not check the compression yet. But regarding the codes P0303, I would focus on cylinder #3 and check the injector and compression.

I found a good article on this :
Part 1 -How to Test the Engine Compression (Chrysler 2.0L, 2.4L)

The gap shouldn't be that high, it was changed to .40 I believe.

[quicksilverdon]

Originally Posted by yannla

Yes, $3000... no comment...
PT is about 100.000kms (62000miles)
We checked the wires with a multimeter, looks good.
We also checked the gap of the spark plugs (bosh, gap .50), looks good.

I did not check the compression yet. But regarding the codes P0303, I would focus on cylinder #3 and check the injector and compression.

I found a good article on this :
Part 1 -How to Test the Engine Compression (Chrysler 2.0L, 2.4L)

Resistance is only one parameter of wires - another is the insulation that breaks down (Particularly with the added heat of a turbo) and allows arcing to engine block producing a misfire. Plugs and wires are a maintenance item and should be replaced together. Plugs and wires are the most frequent cause of a misfire.

[babydolls2004PT]

Guys,

I'm having the same issue with my 2004 Turbo off and on the engine light comes on. I have changed the wires and spark plugs, the next thing to check is the coil. Is there anyway to find out if this is bad, before spending money on the part? I replaced the cam and crank sensors and the pvc valve last year. The car has some hesitation and I can smell gas when I am going up hills or getting on it hard. Does anyone have any suggestions.

Thanks,
Babydoll