cclive

2007 LS2, I'm wondering if it is necessary to remove the intake manifold to replace the oil pressure sending unit, or if it is difficult but can be done without. Has anyone here actually done his own, not had a mechanic do it? I'm looking for first hand info. I'm getting 125 psi and then XXXpsi every once in a while...and surprisingly, it started happening 7 days after the extended warranty expired...

ray_ray

Yes it can be done without removing anything but your cover...i had a special socket made that will fit perfectly on the sending unit..with knuckle and a extension..hardest part was getting the plug of the sending unit..

cclive

Actually, I got the electric connector off easier than I expected. I want to always try the easiest thing first, so I disconnected and sprayed the connector ends with contact cleaner...I'm going to see if that works before throwing new parts at it. Found the new sending unit at Amazon for $33, so that's where I'll be going if needed. By "knuckle", do you mean a u-joint connector for your ratchet?

ray_ray

Yes sir that is correct..

cclive

Thanks for the response...it's good to hear. I have a mechanic friend who said he has two sending unit sockets, one shorter than the other, and that I could borrow one no problem. I'm assuming that yours is fairly short and that's what is special about it? And also, how tight is the unit screwed in? Is it tough to break loose or not bad? I notice that the sensor is mounted on a raised boss and not flush with the block.

haljensen

I couldn't find it but their is (was) a DIY on how to cut the plastic cowl at the base of the windshield above the sending unit for direct access. It was at least a couple of years ago.

Maybe your searches work better than mine.

ray_ray

Besides being a little shorter the side walls are thinner...to get by the intake...there not really very tight..once you break it loose you can turn with your hand...if you can get your hands down to it..good luck....

sick cc

if its reading high, more likely its the sensor, mine went out around 104k. I removed my intake manifold but I have a fast 102. not sure if it can be done with a 102 on but I just removed it cause I couldn't really get to it yet alone see it lol.

frankb

I had done the cut hole under the wiper blades on my C5. Used a coat hanger to unplug the wires and straight down with ratchet and extension. The reason for doing it this way was because the sending unit were cheap and seem to go out fast sometimes.
One thing for sure is you do not want to over tighten because they break.
This was on my C5 so not sure if they are the same. I used aluminium heat tape to patch the hole. This can not be seen from any angle when all put back together. 15-20 min to change out unit. First time took a little longer to cut the hole and remove wiper blade.

cclive

One thing I am definitely going to do is put a towel down behind the sensor to keep from losing anything down there. My SUV still has a stubby screwdriver sitting down there somewhere that will not be recovered until the car is scrapped.

haljensen

cclive: Check the C5 Forum for a DIY, from frankb's post earlier. I know I saw it posted on this Forum but can't find it. Much simpler than removing or trying to work around the intake manifold.

frankb

In the C5 section go to search and put in: cut cowl sending unit. Find amethystvette and he has some pictures on where he cut.

cclive

Found that one...found about 10 more threads also...I've got some reading to do...thanks much!

5 Liter Eater

Why not just take the intake off? Not that hard and you will have unfettered access to the sensor.

cclive

Well here's the follow up. Got the new sending unit from Amazon. I found that if I moved the wiring harness that runs along the fuel rail out of the way a bit, it gave me more room to work. Also bought $8 socket made for the job. It took about 10 minutes to get the old one out. Then when trying to thread the new one, it slipped and fell down onto the block. I could see it with a mirror but couldn't get a grip with fingers. After one hour, I finally got it back using a flexible grabber and said mirror. Then about 10 minutes to tighten it up, first by hand then using socket with u-joint on the ratchet. I'm leaving the FRCs off so I can check for leaks after a drive tomorrow. It is not leaking with the engine running now but I want it to warm up fully and then check it. The only advice I can offer is to get the shortest socket that will still fit the sending unit. Mine was a Lisle and was about an inch longer than it could have been. It would have been easier if it had been shorter. It would not have been scraping on the cowl if it had been shorter. Glad it's done! Thanks for the helpful info.... Martini time.

ray_ray

Great job....enjoy the drink.

saplumr

I'm in this late obviously. I had the same issue but it was only a loose terminal connection. Driving along, oil pressure fine and then XXX then cylcle repeated.

cclive

I was hoping for that...but it was not to be. Mine would gradually creep up from normal and after a couple of hours on the road, it would be at 125 psi. Then it would go XXX for a while. It would show 40 psi or so when the ignition was on without the engine running, so I knew it was the sending unit.

2nd martini good..............................

owc6

When mine went, it immediately pegged and stayed there.

I didn't like it one bit, never having had a car that did that, before.

Cowboy26a

Most say the brass one from Oreillys is the best.