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Yippee Success!!! 04 PT Cruiser

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Basil

Basil

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As I posted in another thread, my younger son's PT Cruiser has been misfiring badly, so I've lent him our Santa Fe while I try to sort out the issue. I had Auto Zone pull the codes and found it was misfiring on two cylinders. So the first thing I tried was to replace the plugs and wires (it was time anyway). Initially I thought that was going to fix the issue because it was running smooth right after that and the check engine light went out. So I took the car back to my son and thought all was good. The next day he calls and tells me the car is doing the same thing again. So I took it back to AZ to check the codes - same codes - same cylinders. Ah ha! It must be the coil pack going bad I thought, so I replaced the coil pack last night. No joy - same issue. After some internet sleuthing I am now leaning towards the likely culprit being a bad intake manifold gasket. Several people on forums described the same issue and that turned out to be the problem. (If not, my next option is the PCM - which I really hope is NOT the issue)

Replaced the intake gasket - again no joy.

I had the codes read again at AZ and this time, all the codes were fixed (probably due to new coil pack) except one. The #3 fuel injector was still showing bad. I pulled the fuel rail and did an ohm checks on all injectors and all were in spec. Next, I swapped #2 with #3 to see if the code would move. It did not. At this point, I convinced myself it had to be one of 3 things. Either a bad connector at #3, a bad wire harness elsewhere (in which case I was toast) or a bad PCM (computer). First I replaced the #3 injector connector. Nope - still bad. So now I could either assume the harness was bad or I had a bad PCM (computer). Before I ordered a new PCM I cleaned the contacts on the existing PCM and seated and reseated the 4 connector plugs several times hoping it was just a cruddy connector . No joy.

Ok, so last week I ordered a new (rebuilt) PCM for $337 from Flagship One. The come flashed and ready to insert based on your VIN.

The new PCM came today. I swapped it with the old one, and viola! That car is running like a champ - NO codes!

It was a bad PCM the whole time!
 
That's always a good feeling when you finally succeed....
IMG_2917.JPG
 
IMHO, you did everything in the right order; cheapest to most expensive. And likely precluded any intake gasket failure or leaking injector seals, later down the road.

Have I mentioned I hate computer controlled cars!?!
 
Congratulations Bas! This saga just reminds me why I hate computers with wheels attached.
 
Here's another good reason, Walt.

shopman4.jpg
 
Good on you for figuring it out
I stop looking under the hood about 1980 not interested nor the patience for anything newer
measuring manuals by the inch instead of pages seems to be the norm these days
 
1958 Rambler owner's manual: 56 pages

2017 Nissan Altima owner's manual: 498 pages. Radio/audio section: 117 pages.

That's just the owner's manuals - not the workshop manuals!
 
DrEntropy said:
IMHO, you did everything in the right order; cheapest to most expensive. And likely precluded any intake gasket failure or leaking injector seals, later down the road.

Have I mentioned I hate computer controlled cars!?!
Click to expand...

Changing that intake gasket was the hardest thing I did. Getting the intake manifold off on that car is a nightmare! It's a transverse motor and you have to reach down between the from of the intake and the radiator to undo the bolts on the bottom edge of the manifold. There is about 2" of space between the radiator and the manifold which results in very scrapped up arms! Then there is a stiffening bracket that connects on the bottom edge of the manifold and extends down and bolts on the block much lower down on the block - I could barely get my socket on that lower 15mm bolt and turning the wrench with your arm jammed in such a tight space was next to impossible! (and no, you can't get to it from below - too much stuff in the way.). It would have been easier if I'd removed the radiator, but really didn't feel like going through the mess of draining the cooling system!
 
:bow: This has been a splendid read, with a joyful outcome to boot. A regular "Who dun it". Turns out the culprit was The Brain... lurking under the hood all along. Thank you for sharing the twists and turns. Kudos, elrey
 
elrey said:
:bow: This has been a splendid read, with a joyful outcome to boot. A regular "Who dun it". Turns out the culprit was The Brain... lurking under the hood all along. Thank you for sharing the twists and turns. Kudos, elrey
Click to expand...

It was quite an adventure. I can't wait to tell the guy at AutoZone, who assured me the problem could not be the PCM "or it would be throwing all sorts of other codes," that it was the PCM that fixed it! (He suggested I but a new Crank Sensor, TPM, Cam Sensor, etc.)
 
Which raises the question ... if the computer system itself, or the actual sensors, are on the fritz, but you don't know it, then the codes sent out are probably bogus.

hmmmm

Reminds me of my (former) doctor, who'd stare at the computer screen telling me what's wrong with me, but never looked at me directly.
 
Basil said:
It was quite an adventure. I can't wait to tell the guy at AutoZone, who assured me the problem could not be the PCM "or it would be throwing all sorts of other codes," that it was the PCM that fixed it! (He suggested I but a new Crank Sensor, TPM, Cam Sensor, etc.)
Click to expand...


Nothing in your description would indicate either of those sensors was the problem. One consistent non-pulse (or wonky pulse) on the same #3 injector would not come from them. If they go bad, it would either not start at all or run so horribly you'd think the thing was gonna grenade itself.
 
DrEntropy said:
Nothing in your description would indicate either of those sensors was the problem. One consistent non-pulse (or wonky pulse) on the same #3 injector would not come from them. If they go bad, it would either not start at all or run so horribly you'd think the thing was gonna grenade itself.[/COLOR]
Click to expand...

That's what I would have thought, but must confess I thought seriously about trying those sensors first before trying the $337 PCM. But logic kept coming back to the PCM.
 
I wish you a lot of luck with your fix.
My Grandsons PT Cruiser would just stop running on the freeway and he would lose his power steering. It was very scarry. We tried a lot of things but I finally came to the conclusion that this is one of the most unsafe cars ever built. No matter what you do to fix it you never know how long the fix will last and under what harrowing circumstances it will happen again. I value my grandsons life so we are getting rid of it and he now has a Mazda 6 that is serving him well.
 
I waited an hour at a car rental lot for another car as all they had when I arrived was a PT Cruiser. Drove one a couple of times and said never again. The first one I had to open the door getting out of the rental parking lot because I could not find the window lowering button. Off to a bad start. with it.

David
 
Congrats. Determination is the key to success.
 
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