Hello everyone,
Hoping someone can help me out. I took my 08 2.7 dodge charger into a local mechanic shop here because i knew i had a bad water pump and a bad coolant housing/bleeder outlet. I had them changed and in the process, the mechanic calls me and tells me that i also needed a new coolant temperature sensor so i get that changed as well. Well, he calls me again and tells me that i also have a bad timing chain tensioner which could have probably caused the water pump to go bad so i also get that changed. So i pick up my car and the minute i crank the car on, i notice that my exhausts don't sound the same. So i drive it around and something is not right. So i go back to the shop a few minutes later and see if i could get a possible answer from the mechanic as to why it was sounding and driving different. So he tells me that it could be because of the new parts and i took that into consideration. Well, the following morning, my check engine light comes on again and to be honest, i'm pissed. So i take it to my local advanced auto parts store to get it scanned and that's when the P0300 code shows up which is a different problem. If i'm not mistaken, this has to do with my ignition coils, spark plugs, fuel injectors. I changed all my spark plugs, ignition coils, and my fuel injectors a few months ago and there were no problems there. My question is did the intake valve cover need to be taken off in order to change the timing chain tensioner because when i looked under the hood, the brackets on the side of the motor were not bolted together to the intake cover. I would appreciate any answers and comments. Thanks for everything.

 

1. If it was just at the shop, I'd take it back and have them scan it, their scanners are A LOT more in depth than the one at Advance Auto and will give a clearer answer than random misfire. 2. I understand the frustration, but I don't feel you got ripped off by the shop, I'm not sure on the 2.7, but I know many motors, the water pump is driven by the timing belt, so when changing one, it is best to change both, because it requires the same tear down, and to have to pay twice would just suck...plus some motors are interference motors, which means if the belt does in fact break, the valves can be stuck open and the piston slams into them...coolant sensor only costs a few dollars to change, they just have a minimum charge. So having it changed when it is already there is a good idea, and to be honest, most shops would have thrown a new one in even if you said no, and just tack a dollar here and a dollar there on different parts of the final bill from the estimate where it likely wouldn't be noticed. 3. Timing belt could definitely cause a misfire. Think about it, it synchronizes the piston stroke to the valves opening, if the computer expects the piston to be in one spot or the valves to be fully open (but they are not) and the computer shoots spark and fuel at the wrong time, it's going to cause a temporary rough engine, even just during one stroke, and the computer compensates. Have the shop clear the code and it may just go away, anything could have happened, turned the key on to push the car out of the shop to get another car in while they were waiting for your parts, and the computer didn't like the readings from the crank and cam sensor not lining up cuz they were moved to take the belt off. They may have had the belt a tooth off, read the code, fixed the belt and forgot to go back and clear the code so it is still in the computer. Just about anything is possible.

In short, confront the shop, they will likely take care of the issue as to not lose a customer and not chance a lawsuit. But make sure they write out a work order for anything they touch, so they can't say something like "Oh, it's been two weeks our work has nothing to do with this new problem causing a misfire" You want documentation that they cleared that code only a few days later and it came back again.

 

Thank you so much HemiMoparGuy1981. I did take it back to the shop and the shop owner looked at it again. He called me back this past Monday and tells me that it's the right side catalytic converter. The converter did need to be changed but was not the real problem. He gives me 3 different options, 1st option from the dealership ($1000), 2nd option was a magnaflow converter ($795), and 3rd option was just an aftermarket converter ($565). I called the shop that installed my exhausts and asked them how much for this job, they said $265. So, I take it to the other shop and after they installed the converter, the issue is still there. I could tell the minute I crank my car on. I ask the guy to put it back on their scanner and come to find out, its the intake gaskets letting in too much air. Soooo, they are fixing that today and asking God that everything comes back to normal. I miss her. LOL but thanks for your detailed response. It is greatly appreciated..!!