Advice - Crank sensor - no spark

[nwracer45]

My nephew has an 04 Optima. He was entering the freeway when his car died. Luckly we have a car trailer and brought it home. I jumped online and started search and came across these forums. There is a ton of great information and we came to the conclusion the problem was the crank sensor. This was confirmed once we where able to locate the computer OBD connection.

The reason I am writing this is that I have seen quite a few people on this site spending a large amount of money trying to diagnose the same problem. Even people leaving theirs cars at the dealer for weeks trying to find the problem. Dealers should be able to plug your car into the computer and tell you in two minutes exactyl what is wrong. Better yet buy yourself a OBDII computer and do it yourself. I bought mine on Ebay for $100. It has already paid for itself many times over. I was even able to get through State emission with an exhaust leak on my truck using it.

Anyways, be aware of dealers scamming your hard earned money when they know exactly what the problems are.

Good Luck!!!!!

[bludragon]

If you are near any auto parts place like advance, pepboys...they will let you use theirs for free. To take it off site might require some more, like rental possibly. Even walmart sells the readers for 100$ if you want your own.

[Floorslayer]

Not to start an argument, but a scanner does not always tell you EXACTLY what is wrong. They are actually designed to target a problem, but not always solve it. Electrical problems can be a prime example ie: you mat have a bad wire or ground in a circuit that will say a sensor is bad, when the sensor is not actually bad. I had a vehicle that kept kicking out a speed sensor code.... replaced the sensor 2 x in fairly short order (because they were known to be a problem) ...when it happened a 3rd tim less than 200miles after the second replacement, I realized there is either something making the sensor go bad, or in my case a bad wire so the sensor wasn't being read by the TCM. A scanner will not tell you that when sometimes it works and sometimes it doesn't and unfortunately stealerships do just replace stuff the first time (or two) before they diagnose further....
Now in your case (i hope your sensor replacement works and it probably will), but here is another scenario ... Your crank could be broken and hence the sensor is not picking up a reference or even worse, the crank broke and crashed into the sensor so now two problems.... Scanner won't tell you that either, but it gets you in the ballpark of a problem... Most crank sensors are an optical type that pick up a spot on the crank every rotation (usually it is a magnet sensor picking up a spot)... Magnets don't usually go bad, but can get coated with metal filings and not read accurately. Replacing or cleaning such sensor will usually solve the problem for a while ( and sometimes a long while) but what caused the metal filing to accumulate....food for thought...

BTW i'm not a fan of stealerships either... But I'm not a fan of just relying on a digital screen to tell me what to do (my scanner) Like my buddy said when cars started to get computerized.... They still need 3 things to run Fuel, Air and Spark..... the sensors are just in the way of providing those 3....

[Koptima]

I agree with you as to the purpose of the sensors...They kick out a result not a cause.