Is my OBD insane?


#1

I have a 2000 Chevy s-10, 4 wheel drive. For the last year (and longer) I have been trying to resolve the service engine light repeatedly coming on. Have checked all the codes and replaced O2 sensor,crank sensor,cam sensor, mass airflow sensor, intake exhaust manifold gasket, fuel regulator,catalytic converter,plugs, wires, distributor, gas cap, alternator, checked ignition sensor, and, finally, a new clutch and a used low-mileage engine. Truck runs great, but periodically the service engine light comes on and off, as does the ABS and brake warning lights, and also periodically many lights come on at once and I lose gas gauge and temp gauge, and the battery light comes on. Then I regain them. What’s going on? I have spent way too much money on this but hate to be defeated by a machine, and at this point I must be close to solving it. What’s left? What should I do? PLEASE help me solve this!


#2

I hate to say it, and I’m no mechanic, but those symptoms to me point more to bad cluster gauges/dash, or faulty wiring to those components. All the other replacements/repairs may have been necessary, too, although someone else may be able to give you a better opinion on that.

Have you been doing the diagnosis and all the repairs/parts replacements?


#3

My father had a car that acted like that. Strange instrument reading, lights all coming on, no rhyme or reason to it. Turned out to be a loose ground connection on the cluster. I suspect your’s will be similar. Either a loose connector, or ground wire, or possible a bad solder joint somewhere on the cluster. Damn hard to find that sort of thing.


#4

I have not done the diagnostics and replacement work myself, but rather used local mechanics, locally highly regarded, and in fact, I believe to be competent to perform the work. However, gone are the days when mechanics actually look, listen, smell, do compression checks, etc. They now seem, sadly, to have become code readers, and rely on the computer to tell them where to go, The ability to diagnose seems to have become a lost art. I have long suspected the computer itself but this has been received with disdain - if the computer was not functioning properly then the engine would not run so well. And the parts replacement goes on, the bank account down, and I don’t have a vehicle I can trust.


#5

Then there is the chance that the engine control computer is out to lunch.


#6

Ty to determine what triggers the on/off situations. If bumps in the road are causing these things to happen it could be a loose wire to the guages or even oxidized connections. Sometimes you have to replace the whole instrument cluster to get the problem to go away - but that is very costly.