Had a lot of guys pm me about how I cut the cowling to fix the oil sending unit. This fix may not be for everybody, it's just what I did. It was very easy and when I decided to do this I also had reservations as to whether I could do it or if it would work. It may not be the best (as you can always remove the intake manifold or let a dealer do it for around $400. I didn't want to take the manifold off, figured I would screw that up even worse. If you consider doing this, read the entire post and become familiar with it. If you feel you're not mechanically inclined, get someone who is to help.

Step 1:
is the cowling that has to be removed.

Step 2:
Remove the rubber hood seal. This is grooved and just slides off. I then removed the plastic cover over the coils. I guess you could do it without removing them but I removed them anyway.

step 3:
Remove the plastic cap on the windshield wiper arm (just pops off). Remove the windshield washer hose from the connector. Mine came off easy, yours may not so be careful and don’t force it. If you just twist it carefully, it should slide off. Then remove the 15mm nut on the wiper arm and remove the arm.

Step 4:
There are 5 push pins along the cowling. Remove the male center pin first, then remove the female part. You don't have to remove the female, I did, so I wouldn't lose it. You should have both pieces out as in the next picture. NOTE: be sure and use the same push pin for the battery shroud, it’s different from the others.

Step 5:
This is the hole I cut with a dremel. I used a small thin cutting disc and it was easy. I angled the cut so I could put the cut piece back in like it came out. Now you can cut the hole bigger and neater but it won’t be seen anyway. It’s up to you on that. Now you can see the OPS that causes all the problems. I used a small wire to release the lock on the electrical connector and pulled the connector off. I used a pair of long needle nose pliers to put it back on. You then need a deep well 1 1/16” socket to remove the OPS. I used tape inside the socket so the OPS would not fall out of the socket. ONE THING YOU HAVE TO BE CAREFUL WITH: Before you cut the hole, feel underneath the cowling (where the OPS is). There is a hose and and a electrical wire connector (blue color if I remember correctly). The hose is the PCV, I don’t know what the blue connector hooks to. I put a thin aluminum plate under the cowling where I did the cut so I wouldn’t hit these. No biggie, just thought I would let you know. Also, I was asked if you could use a hole saw. I never thought about it but I suppose you could. Just use a short starting bit so you won’t hit anything. If you put a metal plate under the cowling, you shouldn't have a problem. This is fiberglass and cuts real easy.

Step 6:
I then put the piece of fiberglass that was cut back over the hole. If fit nicely. I had a square piece of pliable rubber (about 1/8” thick), put 3M tape around the 4 sides and put it over the hole as you can see in the last picture. Fit perfectly. You can cover the hole however you like, it won’t be seen anyway. The good thing is if it the OPS ever has to be changed in the future it will an easy job.

Install everything in back in place in the order you took them off. Special note: the push pins that came out of the cowling (you may not have noticed), one of them is different from the rest. This different one goes into the lip of battery surround shroud. If you feel underneath the cowling you will feel the flange of it. That particular push pin holds that in place.
The biggest advice I can give, if you do this, is take your time and pay attention to what you are doing. Don’t get in a hurry and don’t force anything. There’s nothing in this procedure that requires anything to be forced or pulled with force.
Like I said, this is a easy fix. But it may not be what you would do or how you would do it. You can always take the intake off. AS ALWAYS, “To Each His Own”.
If you have any questions, comments, or if I left something out, let me know and I will correct this post and surely give you credit for it.

Thanks,
Gregg

 

When I use this procedure I cut a very neat square hole with a dremel and put the piece back with Black RTV Silicon.

You have to look hard to see where it was cut. Plus you would have to pull the wipers and cowl before you could even look.

I see nothing wrong with adding an access hole that GM should have put there in the 1st place.

 

My sentiments exactly!

 

Great writeup and pics to go along. Thanks for the procedure and warnings.

 

Thanks for posting this up. I'll add it to the rest of the files I have on the oil pressure sensor fix.

 

Nice writeup Greg, thanks