Anyone know anything about those computer auto engine anaylizers?

[Pete Lamberty]

Hi Everybody,
I was wondering if it was worth while for me to get one of those engine analizers that tell you whats wrong with your car. My "service engine soon" light will come on for a few days and then it will go off for a few days. The car was running really rough while the light was on so I took it to the local garage. The guy put it on his analyzer and it told him the car needed spark plugs. Well, that all came to $150.00. I feel like I could have done that mself. The car ran fine for a week or two and then the light came on again. It was also running rough again. Well, I figured I am not going to pay $150.00 again so he can put spark plug wires on it. So I replaced them myself. The car runs great, nice and smooth. But the "service engine soon" light stays on. So I think it might be a good idea if I buy an engine analyzer to figure out what is wrong with it. It is ten years old with 87K on it. Do any of you have them and could you reccomend a brand to buy. Any thoughts on this are appreciated. Thanks, Pete

[Steve Dewey]

I have the palm version of this

http://www.auterraweb.com/

This site will help you interpret the codes

http://www.oemaudit.com/Links.cfm

another site w/ codes

http://www.troublecodes.net/technical/

Note OBDII scanners generally work on cars 1996 and later. Some may have adopted the standard early (vs the OBDI).

[Lee DeRaud]

There are two types of widgets that can be described as "engine analyzers":

First, there are the (small/cheap) things that plug into the diagnostic port and read the codes output by the engine's computer. All that does is tell you what the engine thinks is wrong, so you can then look up in the manual how to fix it. That's what your dealer already did...I suspect that plug wires were the next thing on the "replace" list, but they're more expensive and usually harder to install than the plugs themselves. So if you were using one of these widgets, yeah, the plugs probably would have been your first try too. (Although $150 to read the codes and replace plugs sounds really high, unless you have one of those cars where you have to disassemble half the engine to get at all the plugs.)

If that course of action doesn't fix the problem, you turn to the (big/expensive) things that actually monitor the engine's various voltages and functions while it's running (basically oscilloscopes that are long on input channels and short on data rate). They can isolate things like bad sparkplug wires, but require a bunch of specialized training to operate and interpret the results.

Just so you know what you're getting into...these days, a "shade-tree mechanic" is really a computer technician. Being able to read out the codes gives you a leg up when you're talking to the service department, but it isn't a "silver bullet".

[Matt Meiser]

Autozone will check and clear your codes for free. I would assume many other auto parts stores will do the same. Harbor Freight has a OBDII scanner which runs about $40 on sale on a regular basis which I've been considering getting. Actually when it was first introduced I had a coupon to get it for $29.99 and missed the expiration date . For OBDII, the scanner just plugs into a port under the dash and is very easy to operate. The code comes up on a display. Much better than the old systems where you had to count flashes of a light.

[Matt Meiser]

Although $150 to read the codes and replace plugs sounds really high, unless you have one of those cars where you have to disassemble half the engine to get at all the plugs.

I don't know--it cost me something like $45 just for the spark plugs themselves on my old Ranger (v6). The factory plug was a platinum plug. I could easily see someone charging $150 for that by the time you figure their markup on the plugs and labor.

[Pete Lamberty]

I guess I am thinking of what Lee would call the small cheap widget kind. It just plugs in and tells you what the engine thinks is wrong. Thanks Matt for the tip on the HF item. If anyone knows of others please inform me. If anyone is interested I have the bill in front of me. It was $50.00 to scan, $55.00 for spark plugs and $36.00 for labor. The scanner read out was random miss fire P300. Pete

[Lee DeRaud]

If anyone is interested I have the bill in front of me. It was $50.00 to scan, $55.00 for spark plugs and $36.00 for labor.

Probably 0.5-0.6 hours flat-rate to do the plugs: that's $60-$72/hour, pretty typical these days. The $50 scan fee is ridiculous.

[Steve Dewey]

There are two types of widgets that can be described as "engine analyzers":

First, there are the (small/cheap) things that plug into the diagnostic port and read the codes output by the engine's computer. All that does is tell you what the engine thinks is wrong, ....

If that course of action doesn't fix the problem, you turn to the (big/expensive) things that actually monitor the engine's various voltages and functions while it's running (basically oscilloscopes that are long on input channels and short on data rate). They can isolate things like bad sparkplug wires, but require a bunch of specialized training to operate and interpret the results....".

The auterra unit is somewhere in between the $40 HF reader and the multi thousand dollar professional units. It reads some parameters real time, not just the "code" and can help troubleshoot. Of course, if you don't have the manufacturer's service manual, none is going to be of much help troubleshooting. The auterra unit is $250.

I'd rather head to autozone than spend the $40 on the HF reader.

[Matt Meiser]

From what I've seen the one Autozone uses is just a code reader, not a real time monitor--which is why I haven't gotten the HF one yet. That and my oldest vehicle just got traded in on a brand new one.