Recommended Posts

Finishing up a engine rebuild for a customer in NC. I had one more engine arrive for a head gasket and a lower reseal from MI. Thanks again for your support guys.

post-18826-0-47909700-1410268448_thumb.j

Share this post


Link to post
Share on other sites

What is a lower reseal? When you rip apart these engines, is there anything inside that is causing low oil pressore or an internal oil leak that causes low oil pressure? I have no leaks at all, but the oil pressure flicker after high rpm driving.

I am starting to believe there are 2 issues that hit alot of older N*'s - headbolts, and low oil pressure . of course both are unrelated.

Share this post


Link to post
Share on other sites

What is a lower reseal? When you rip apart these engines, is there anything inside that is causing low oil pressore or an internal oil leak that causes low oil pressure? I have no leaks at all, but the oil pressure flicker after high rpm driving.

I am starting to believe there are 2 issues that hit alot of older N*'s - headbolts, and low oil pressure . of course both are unrelated.

The lower re-seal consists of re-sealing the upper and lower crankcase halves as well as replacing the oil manifold plate which is between the oil pan and the lower crankcase half. The oil manifold plate has oil passages in it and quite often, if there is oil leaking to the ground, it is from the seals that have gone bad in this plate.

The use of the GM Engine Sealant is required and the engine will be leak free after the procedure.


Kevin
'93 Fleetwood Brougham
'05 Deville
'04 Deville
2013 Silverado Z71

Share this post


Link to post
Share on other sites

Low oil pressure could be a saturated oil pressure switch and connector that should be cleaned out with brake clean. If the problem persists after that you might be loosing oil pressure through the main bearings, excessive clearance. What some people do including a long time customer of mine with a 97 Deville is running 15w40 Rotella oil during Summer early Fall and switch back to 10w30 in late Fall/Winter. This has been going on for many years wit no engine issues at all. Keeps the light off and cheaper than a rebuild.

Share this post


Link to post
Share on other sites

Sometimes it's just the switch. It's on the oil filter adapter and can be damaged in an oil change. A damaged switch can also seep oil, making the oil pan wet. It's hard to reach but inexpensive, and lots of people have fixed a flickering oil light at hot idle by changing the switch.

I had a tech tell me that my case half was leaking on a Jasper that I knew was dry as a bone. So I bought a new oil pressure switch and had my filling station change it when they did an oil change. At the next oil change, the oil pan was dry as a bone.

If it's not the switch, the oil pump is much more likely to wear than the mains and rods and cam bearings and lifter bores. It's behind the damper wheel in the front and not easy to change, but it's there and doesn't require a full tear-down to change for just that reason.

If the engine has been run without oil, or raced or otherwise abused without protection such as synthetic oil and an external oil cooler, that's another matter. But I've never had someone come to Caddyinfo complaining about low oil pressure in a racing car or after running it low on oil.


CTS-V_LateralGs_6-2018_tiny.jpg
-- Click Here for CaddyInfo page on "How To" Read Your OBD Codes
-- Click Here for my personal page to download my OBD code list as an Excel file, plus other Cadillac data
-- See my CaddyInfo car blogs: 2011 CTS-V, 1997 ETC
Yes, I was Jims_97_ETC before I changed cars.

Share this post


Link to post
Share on other sites

I replaced the switch a few months back, and thought the problem was behind me. the switch definitely was causing the almost constant flicker. With the cooler weather coming, the car stays at 196. Flicker starts when the car peaks at 219 degrees. also put in a bottle of motor honey a few weeks ago, and haven't seen the flicker since. Next quart will be 15w.

Share this post


Link to post
Share on other sites

The oil pressure switch can go bad again with a twist of a wrench, slipping off the oil filter and whanging the insulator or connector of the switch.


CTS-V_LateralGs_6-2018_tiny.jpg
-- Click Here for CaddyInfo page on "How To" Read Your OBD Codes
-- Click Here for my personal page to download my OBD code list as an Excel file, plus other Cadillac data
-- See my CaddyInfo car blogs: 2011 CTS-V, 1997 ETC
Yes, I was Jims_97_ETC before I changed cars.

Share this post


Link to post
Share on other sites

The oil pressure switch can go bad again with a twist of a wrench, slipping off the oil filter and whanging the insulator or connector of the switch.

The oil pressure switch is so far above the oil filter and blocked by the oil cooler pipes, I don't know how it could be damaged when changing the oil filter. I had a very difficult time changing the leaking sensor on my '97 STS. I thought I was going to have to remove the oil cooler pipes.


Kevin
'93 Fleetwood Brougham
'05 Deville
'04 Deville
2013 Silverado Z71

Share this post


Link to post
Share on other sites

The oil pressure switch can go bad again with a twist of a wrench, slipping off the oil filter and whanging the insulator or connector of the switch.

The oil pressure switch is so far above the oil filter and blocked by the oil cooler pipes, I don't know how it could be damaged when changing the oil filter. I had a very difficult time changing the leaking sensor on my '97 STS. I thought I was going to have to remove the oil cooler pipes.

KHE - Thank you for pointing that out - but the point of my post is that an oil pressure switch can go bad anytime. The one that I had replaced to fix a "case half leak" was about two years old.

And, yes, the wrench would likely be attempting something other than an oil filter removal or installation. But I didn't want to go there.


CTS-V_LateralGs_6-2018_tiny.jpg
-- Click Here for CaddyInfo page on "How To" Read Your OBD Codes
-- Click Here for my personal page to download my OBD code list as an Excel file, plus other Cadillac data
-- See my CaddyInfo car blogs: 2011 CTS-V, 1997 ETC
Yes, I was Jims_97_ETC before I changed cars.

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Sign in to follow this  

  • Recently Browsing   0 members

    No registered users viewing this page.