What Code Reader/Scanner to Buy?

[LBJ]

I have just seen a problem light appear on the instrument panel. It's the engine symbol that indicates I have a new problem somewhere in the engine. Now, what is the name brand of a good scanner to connect so I can determine what the problem is? I bought an EX-SCAN 3000 back in the 90's for my 1991 GMC P.U. and it's now WAY out of date and Autoxray no longer is in business as I've read. Looks like it's a piece of junk now. I have a 2004 Chevy 5.3 V8 in a Silverado Ext Cab Z71. Thanks. LBJ

[LBJ]

Because my oil needed changing, I did that with a new filter. After that, I disconnected the battery for 10 minutes. Upon power up and starting the engine, the ENGINE (icon) light went off. Apparently, the oil filter was clogged. It has been making a light clicking noise lately. So, that was probably the lifters. I had a brand new 1984 Olds just out of warranty and it started making the same noise. Changed the oil and filter, noise went away. I replaced the Silverado filter with a High Mileage Mobil 1 filter and the oil pressure is kinda high - 40 at idle and 50 at highway speeds. Just wonder if they increased the spring pressure to make oil pressure higher for high mileage vehicles? Hard to say. But also changed out the spark plugs as well after 90K miles. They still looked pretty good, but as long as I was under the hood, and the day was cool, did that as well as changed out the anti-freeze. Haven't done that since I bought it new, 13 years ago this month. Ha. Test drove about 10 miles and some highway speeds, all ran well. Guess I'll stumble across a code scanner sooner or later. Lucked out this time.

[lowrollin70gmc]

I bought the ANCEL AD310 code reader via Amazon a few months ago. It works well, and does give some live data feeds for diagnostic work. It’s not a fancy model but for $35 I’m happy.

https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

I’m not sure about your oil change questions, but I would imagine the oil weight and type to be responsible for the pressure change and not the filter bypass spring (I think that would be set much higher than 40-50psi to bypass excessive pressure). For reference, my 04 Burb’s 5.3 has nearly the same pressure readings with 281k, a regular WIX filter, and 5-30 conventional oil.

[LBJ]

Hi Andrew, thanks for your comments. I've been running Mobil 1 since I bought the truck in 2004 with the first oil change. The pressure just seemed higher than normal. Even though I have 90K miles on the truck, it might not really be "high mileage" and not as worn since I have always used synthetic. But, Mobil lists High Mileage as over 75K miles. Tighter tolerances makes higher oil pressure in my mind. Hard to say. I just don't want to put too much pressure in there to create additional wear.

$35 for a code scanner isn't bad at all. I got lucky this time, but next time may need the reader. Lane

[lowrollin70gmc]

I’m not sure what’s up with the pressure then, especially as you know the history of your rig and use the same oil every time. I’m not worried about high pressure, as these do use a crank driven oil pump and won’t wear on the cam and distributor like older engines. Maybe the higher pressure is what is causing the lifter tick to disappear?

[LBJ]

Andrew, maybe so. I'll keep an eye on oil pressure. Funny, back in the 70's -80's, I usually saw oil pressure dropping on cars I owned and was worried about that. Now it's too much oil pressure that I worry about! Ha.

[LBJ]

The latest is that the oil pressure hit 70 PSI driving into (local small town) to get gas. That was at 65 MPH. This morning I drove into Fort Worth to have the Chevy dealer look at the engine to see what they could determine. First off, the oil pressure was 70 PSI when accelerating, but leveled off at 50 PSI, and the more I drove the lower the pressure went. By the time I drove 30 miles, the pressure never got to 60 PSI and usually was between 40 and 50 PSI. I think the oil pressure sending unit is fluctuating and may need replacing. Engine sounds good, no oil leaks, runs good. So, kind of a strange deal. I will keep an eye on it and will replace the sending unit. I told the Chevy service writer what the deal was and told him I guess I wasted a drive in to town. Didn't leave it with them at all. Glad it got better, not worse, the more I drove. Now, all I need to know is where on the block is the sending unit? haha. Hope it's not in a hard spot.

[406flyfish]

It’s on the drivers side of the engine, behind the intake manifold. It’s easier to follow the wires to the connector. It also takes a oil pressure sensor socket. 1 1/16th inch. You can get it without removing the intake manifold FYI.

[LBJ]

Oh good. I just watched a video on remove/replace the sensor where the guy pulled the intake, alternator, fuel bars, and no telling what else off! I said, Crap, that's not gonna happen! hahaha. Glad to hear it can be done without that mess and a 1-1/16 oil pressure socket as they don't give the size of the nut on the sensor. Thanks, LBJ.

[LBJ]

Got my new oil pressure sensor and socket, got out to the engine bay, and dayum, that sensor is almost impossible to get to! It's way farther behind and below the intake than I thought. Got several things in the way and I cannot even snake my hand down there. Guess that video on changing it out was right - gotta pull the intake. Have to think this one over some. Ha

[LBJ]

Bought a code reader from Rock Auto, came in today. Hooked it up this evening and it said No Codes. So, guess that's good. But it has a definite miss on idle. You can feel it bang and shake the truck a bit. I installed new plugs the other day after I changed the oil. Maybe one plug had a crack which would make a miss. Or, maybe I didn't get the plug wire back on all the way down. I'll look at that tomorrow. Other than that, the truck runs fine on the road. The Scan Tool is by PT, Performance Tool. Handles CAN and OBDII codes. One mystery I couldn't find the answer to is what I/M means. I looked all the intro data and that acronym isn't covered. The instruction booklet really doesn't explain the full use of the reader, but maybe I'll figure it out.

[BR3W CITY]

I/M is usually in reference to I/M readiness monitors. They are ECM set "flags" of activity that exist to monitor cycling of certain systems. If you were to watch it on a monitor like HPT ECM Scanner, you'd see they have counts that track certain things like start cycles, mileage etc.

When you scan and clear codes, it sets the cleared systems to 0. For things like emissions systems, its usually around a 200mile cycle. This is so you can't spoof the system by rapidly force-clearing codes. Its basically a bull**** detector. The most common way to observe this is with the gas cap emissions code (evap). If you loosen the cap and start the truck, it may see the pressure drop and trigger the code. You can then go tighten the cap and drive a little bit...and once a requisite mileage amount or start cycle count is reached, the code will clear itself because its observed the "failure" as no longer there.

[LBJ]

BR3W City, thanks for the clarification on the codes. The code reading/reporting thing is a world unto itself.