96 engine light comes & goes..odb2

[96tsport]

Had an engine light come & go for awhile but from what I read, if the CEL light goes out, means everything's ok for obd2 setup. So, I figured something minor like a fouled plug(s) that was clearing up..

Ship was running good this way but was getting worse recently, engine shaking on start & idle getting (more) erratic, but no probs when adding power. The other day though, clearly lost a cyl at slow speed from starts (air on). Just went to pick up my daughter from summer school ..~ 15 minutes of a slow speed stop & go drive.

Had a 1 hour trip (& back) planned early the next morning at highway speeds so ended up scoping the engine (all I could get done at the last minute..) & came back with a misfire in #1 cyl, front 02 sensor & egr valve not set right.

So ..moral of the story is that, even if the CEL light goes off ..doesn't necessarily mean everything's ok. Even with the above probs, CEL light went away ..sometimes.

Wrench did an interesting test that I'd not seen before, just prior to scoping the engine. Pressed on the brake & added power which I suppose is meant to test the engine under load. Clearly, 1 cyl was not firing in that situation.

2 hr highway trip the next day worked out ok & have since changed the 3 rear plugs (to ac platinum ..crappy said 1 hr labour..took almost 5..) & wires, & the front 02 sensor (so far..). Crappy tire also had the egr for ~ 125 bucks. From what I read here so far & even pricing it online, didn't see anything cheaper.

Plugs of course tell a tale & plan to get some pix together to post. #1 cyl was slightly oil fouled & the other 2 had evidence of coolant contamination (whitish deposits & some crud buildup) but all appeared well worn with huge gaps.

#1 also had a piece of porcelain broken off which I assume passed & might explain some ticking noise I was hearing there for a bit. The part that bends over the electrode was almost gone.. very thin. Plugs were ngk platinum.

Turns out the rear plugs are pretty easy on this setup .. if you know what you're doing. This post was the key & mentioned it to the young mech after he fumbled around with stuff for over 3 hrs trying to get to the plugs. The coil pack has to come out & not sure if it had to be done but he loosened the alternator to reach the #1 plug. He removed the top front engine connection (dogbone?) but did not succeed in moving the motor forward. Prolly didn't know about this & I think that the tranny has to be in neutral when tilting the engine forward, or there is a risk of breaking the motor mounts.

http://www.automotiveforums.com/vbul...54#post3663754

[96tsport]

Just an update. Changed all the plugs now & all wires, as well as the front O2 sensor (Bosch..) Drove it a bit & CEL light came & went so changed the egr valve & same thing (only thing left was P0441).

Mech said the codes had to be cleared (no charge but does disconnecting the BAT clear codes?) to see if there was still a prob so had that done & CEL light still came & went.

Only code now & only thing I haven't dealt with is P0441 (another thread) which mech sez is no big deal & van is humming.

Went over the paperwork from when baught & made a mistake. Have been saying ~ 25k in the last 2 years but it's actually ~ 45k (kilometers).

I'll post some spark plug pix when I get a chance & sort it out.

#1 & 6 are distinctly different from the rest & appear black (unlike the others) with some oil fouling, but didn't seem bad for ~ 45 k of driving (that I know of) & considering how much oil is being used (~ 3+ litres per oil change) Both plugs were also missing some insulating porcelain from the center electrodes.

Had a bit of a scare, when the mech was (trying to..) pulling #1. Asked me if i wanted to continue cos he felt that the plug might break & if it did, it was my prob.

I had a look & felt to me that the plug was turning.. which it was.. Sooo, lucky moment for me & lucky also that they let me have a go at it. That plug had to be dealt with ..one way or another.