2005 Silverado 5.3 5300 V8 - The oil px gauge last night all of a sudden pegged out. Check the oil and the level was good, oil was a worn ...

The oil px gauge last night all of a sudden pegged out. Check the oil and the level was good, oil was a worn so thought it could have been a clogged filter. Changed the oil/filter and still pegs out. Trying to figure out how to get to the oil px sensor/sending unit without taking the engine apart. Anyone have any tips or ideas?
Thanks

It's on the top of the block on the drivers side behind the intake. You can see with the right angle, but changing it is a lot by feel. The only thing I took off was the plastic intake cover. You need a special socket to remove it, although it's sold at most any parts store. Don't rule out the cluster as the problem. Clusters in these are known for stepper motor issues.

tsduke is correct. The oil press gauge in my 2003 did the same thing about a year ago. I used my Snap-On diagnostic scanner to perform several "gauge sweeps" and concluded that it was indeed the oil pres sending unit. Not too fun to change; my wrist looked like a human sacrifice from scraping on the metal clamps on the fuel rail when I was done!

I know that this is an old thread, but if anyone happens to read it, I can use a bit of help. I'm replacing the oil pressure sensor in my 05 5.3L right now, and as the previous posters stated, much of this is done by feel if you're trying to avoid removing the intake manifold. I've removed the sight shield, and now I can just get my hand down to the sensor (and my forearm and wrist are already bleeding pretty profusely), but I can't tell by touch how to disconnect the sensor electrical connector. It's a bit smaller than what I expected when looking at the new sensor (or at least it feels small). I'm working at night with crappy artificial light, so I can't even visualize it very well with a mirror.

Does anyone have any hints, tricks, or a much larger illustration of the same type of connector that they could share with me? The illustration from the service manual that tsduke posted is too small and unclear for me to make out how it locks on to the sensor.

Thanks

You should be able to feel the clip around the sensor and pull it back with your fingers. I understand sometimes you can not get enough leverage in tight spaces. If you are pretty mechanicly inclined I would suggest taking off the intake manifold. I't really easy and should only add an hour or two to the job (may make it less if you can get to the sensore easier).

Thanks for the reply ASTE25. Stubbornly, I spent almost all night doing it without removing the intake manifold. Having the benefit of hindsight, I would definitely recommend removing the manifold. I ended up having to grind down the wall of a pretty expensive 27mm socket to fit snugly onto the sensor while clearing various protuberances around it. Not to mention that my hand and forearm are now also ground (like hamburger). Once I had struggled with it for about an hour, I decided that intake manifold removal was the only sane route, but it was too late to get a new gasket for it, and the factory manual explicitly warns against re-using the old gasket, so I didn't want to risk it.

Anyhow, now I'm FINISHED! The reason I'm posting this lengthy post is because I hope that the next guy/girl who searches for info re this job can benefit from my lesson.

Sometime what initially seems like more work is actually the easiest way to do things. Glad you got it done. Did you wind up taking the manifold off, your post confused me a bit.

Sorry about any confusion; I was just kind of giddy from exhausion when I wrote that last post. No, I didn't end up removing the intake manifold because it was way too late to purchase a new gasket, and I had to get the job done by morning. My point was that if I ever have to do this job again, I will definitely remove the manifold. Next time I will make sure I have a new intake manifold gasket on hand before I begin; It can always be returned, if I don't use it. Skipping that step (manifold removal) cost me at least an extra couple of hours, not to mention a pretty mangled hand and forearm.

Well, hopefully there will not be a "next time" for this repair.

2007 GMC Sierra (NBS)

Removed the plastic cover, changed Oil Pressure Switch in about 20 minutes, all by feel, have X-Large hands, scraped up a bit, but managed.

Tools: All 3/8" drive,,, Oil Pressure Switch Socket 1-1/16", 6" extension, u-joint, ratchet. U-joint on top of socket.
(I was prepared with several lengths of extensions, and a rocker adapter, but didn't need them.)

No way I would take off the intake manifold!

Thanks for the info!