like the title said, how can i check the rear rockers?
my car sounds like its got a knock, but it sounds like on the outer end of the motor... im thinking bent rocker or bad lifter...
but yea, is there any other way other than stephascope (sp?) and removing the intake to check them? like any tell tail signs?
1) tilt the motor forward
2) remove rear valve cover
might need a mirror and a light to see the inner halfs of them, as they're a bit hidden by the lower intake manifold.
to check the lifters, I think what you can do is pull both (or one at a time) valve covers, start the car, and watch the rockers. if one isn't moving, you've got a collasped lifter. don't worry about the valve covers being off with the motor running, at idle speeds it'll hardly spray out at all. surround the area in a rag if you want.
knocking noise could also be an exhaust leak, i'm told. possibly the EGR tube. you wouldn't be able to see it without removing the heatshield sleve. you might be able to feel the exhaust leak around the edges of the shield with the car running, other than that you'd have to remove the EGR and block off the intake/crossover, and see if the noise has stopped.
compression check would be the easiest method to see if a pushrod is bent, but a visual inspection is probably the best bet to see if the rocker is loose or whatever.
Be warned that several of us have experienced a bad camshaft, particularly on lobe #10, which is exhast for cylinder 5 IIRC, so it's probably in your best interest to remove the rocker arm cover and inspect.
I usually just remove the alternator bracket, the belt as well obviously, then the MAP sensor and evap sensor and bracket right off the back of the plenum, then its mostly accessible from there. There are four torx bolts holding it on. I bought new bolts from the dealer that now use a 1/4" bolt head instead of torx so they go on a bit easier. They also come with new grommets so you know they won't leak, mine did and it was surprisingly bad. Then I would just remove the fuel pump fuse and turn it over to see if they are all moving, particularly the said lifter on lobe #10. You could also turn it over by hand if you remove all the plugs, but you will know right away if a pushrod is bent, make sure to pull them out and put them back in on the right lifter, they are different lengths for exhaust and intake. That will definetely ruin a lifter/pushrod/valve. Good luck.
Quote from: R Dubya on August 17, 2007, 05:31:14 PM
Be warned that several of us have experienced a bad camshaft, particularly on lobe #10
that too. and boy does it suck when that happens :cussing:
ya, in my old 91, I had the cam replaced... would have never really known it was bad if I didn't blow a head gasket... but my old buddy basically rebuilt the motor after that point... damn I wish I kept that motor... :icon_frown:
yea, i have a feeling that the cam is screwed... i plan on pulling it and droping in a normal 3.1 with 58k on it til i get the turbo one rebuilt... plan on doing a whole new valve body, re-do the heads, better valve train parts, and a nicer cam...
kinda off topic, but how often do these motors fail on the botom end? i havent heard of a problem yet with them... but wondering anyone elses results
Quote from: 90grandprixstet on August 18, 2007, 01:58:58 AM
kinda off topic, but how often do these motors fail on the botom end? i havent heard of a problem yet with them... but wondering anyone elses results
make sure your fuel pump wiring doesn't twitch at 8 PSI and that you're not using plugs that are too hot and you'll be good as gold :D just keep up with basic maintenance