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Botched Timing Belt Replacement & Check Engine Light

I took my 2004 non-turbo base model PT Cruiser with 88,000 miles in the day before yesterday to the dealer with the cheapest bid for a timing belt change. They said the car would be ready in 4 hours, and it ended up taking all day yesterday and this morning because of a supposed issue with the water pump.



Then, I get a call this afternoon, telling me that they had put everything together, and took it out for a test drive. According to them, the car ran smoothly, but then started running really rough. They took everything apart again, and checked their work on the timing belt, which was fine. Now, they seem to think it’s something else.



The check engine light was on when I took it in, but it just comes on and goes away, never running rough. I know that I should have gotten the engine light checked out earlier, but, it seems to be a little weird that the car was running absolutely fine until I just happened to take it to their garage.



(The engine light problem dates back to when it was under warranty. When it was under warranty, they (the original dealership) replaced all the wires, and the ignition coil. Although the light comes on, I haven’t had any problems with it since.)



They ran the codes, and said that it was showing 1 and 4 misfiring, and that it told them to check the cam sensor and oxygen sensor, but those are fine. They’re stumped, and gave me a loaner car to drive around “until they figure it out.”



What should I do? This is my only car, and I can’t afford to buy another one, or even to pay much more on top of what I’m already paying for the timing belt.



PS: They’re replacing the timing belt, serpentine belt, and water pump. I asked them about replacing the timing belt tensioner, but they said that they would have to check to see if it was pneumatic or not, because supposedly, pneumatic tensioners do not need to be replaced. However, it seems like the people on this forum with PT Cruisers replace their tensioners, so I’m wondering if the guys at the shop even know what they’re doing…(?)

The hydraulic tensioner does not come with a timing belt set but in my opinion it should be part of the job.

There’s really not enough info known to make much of a guess and without having car in hand it’s even tougher.
It’s also unknown if a screwup occurred and you’re being BSed so they can cover their tail.

If the car were given to me I can tell you what my first step would be. That would be a compression test and vacuum test to verify that compression is good and something has not happened to cause low compression, such as a mis-timed or jumped timing belt.
I’m pretty sure this engine is an interference fit, meaning valves may bend if something is out of whack.

If the compression is good, and since cylinders 1 and 4 are not adjacent to each other, then one has to consider the coil, plug wires, plugs, wire connector plug at that coil, etc.
I think looking at the cam sensor and an O2 sensor as the cause of misfires on 2 cylinders only is a bit misguided. This does smack a bit of guessing in my opinion.

I don’t want to accuse these guys of anything but if the compression is down on 2 cylinders and factoring in the story about a water pump issue along with the assumed guessing about the problem, the truthfulness of their story could be in question to phrase it politely.

I’m guessing that they’re not giving me the whole story, but I have no idea how to handle this, or what to do about it. Does anyone have any advice?

They said it’s the computer. They said that they would pay for it, so that’s nice, but I’m still wondering if that’s the problem at all. It seems a little odd that changing the timing belt would make the computer go bad, no?

There may be no connection. You said the engine light problem predates the timing belt installation. The computer may have been bad, or going bad, before the timing belt job.

Take the free computer and don’t worry about it.

I got my car back last Friday afternoon, and, as far as I could tell, it was running fine. I hadn’t driven it very far until yesterday (Monday night), when I drove about an hour out of town and back. I noticed some hesitation on the way back, but it wasn’t very bad. This morning, I started the car, and it died out (I might not have cranked it for long enough). On the way to work, I definitely noticed a distinct hesitation in the early parts of acceleration (it felt like I was “lugging” the engine, even though I was shifting properly). During lunch, the problem got even worse: the hesitation and “lugging” feeling got so bad that I thought the car was going to die. At one point during the last episode, the engine light flashed on and off (and then stayed off). It seems to be worst in second gear, but it happens in all gears. I took it to the dealer who worked on it, and they dismissed the possibility of it being a timing belt issue right off the bat. In his words: “the timing is either on or off. If it’s the timing belt, it won’t run.”

Is this true? Considering the problems they’ve had with it before, I’m not sure I trust their diagnosing abilities. What should I do?

If the engine light came back on did you have them pull the codes to see what it meant?

If the timing belt was off you most likely would have noticed symptoms immediately and they would not change; the car would not run fine and then start acting up on an intensifying basis. Of course anything is possible however I believe it is not related.

The engine light flashed, but it never stayed on. It’s not on right now, so I don’t know if they’ll be able to pull the codes.