Expert: Roland Finston - 1/27/2012

Question
QUESTION: just purchased a 01 town and country havin a few problems w it. nothin i didnt expect though being used and all. my speedometer is off 5-10mph. how do i go about fixing this problem w out spending the high dealer fees?


thank u,

nick

ANSWER: Unfortunately that modification to the setting of the transmission control module can only be done using a rather sophisticated electronic diagnostic tool. You might get it done at an independent trans shop for less money. It is not a lengthy prodecure to change the setting but it does require the tool to do it.

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QUESTION: I might as well ask another question while I'm on here. My van has 138k it started2 hesitate and auto zone told me it was cyl # 2...I took 1 plug out and it had a lot of carbon on it. Would u recommend a complete tuneup or just changing the plugs?

ANSWER: Hi Nick,
The cause of a misfire could be many possibilities. If you don't know how long the plugs have been in then changing them may be the least expensive first step, and you can do it yourself. So try that. About the only other simple possibility is that the spark plug wire on cyl #2 is defective and allowing the voltage to short to another wire or the cylinder head. So when it is dark out open the hood and observe the spark plug wires as the engine idles to see if you see any signs of such arcing. As to a 'complete turn-up', that is an out of date concept. Rather you should rely on the fault code readout to troubleshoot for the specific problem. It might be that the fuel injector of #2 is leaking, which would explain all the carbon. If the other plugs are not similarly carboned, then that would indeed suggest that possibility as the cause of the carbon on @2. You might also check the compression of that cylinder. So focus your attention on the fault code approach.
Roland
PS Thanks for the nomination. You can do it again with this new question if you choose. Thank you.

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QUESTION: I went ahead and replaced the plugs andwires in my 01 t and c. I still have the same problem. The tuneup didn't m make a difference. Where would u go next?

Answer
Hi Nick,
Were all the old plugs similarly carbon-coated, or just that for the #2 cylinder?
If just the #2 was obvious, then I would check the compression on that cylinder, and if that is at least 100 psi and within 25% of the other cylinders' psi readings, then I would suspect that you have a leaky injector at that cylinder. If they all looked bad, the other thing might be to drive it for a while on the highway preferably because you don't know the driving history of this used car. It could have been mainly run on short trips and low rpm so it built up alot of crud in the combustion chambers which may be blown out by running it at higher sustained rpms. Let me know what you find/found.
Roland
PS Thanks for the earlier rating and nomination. You are entitled to do it again with each new question if you choose.