TheAMCForum.com Homepage
Forum Home Forum Home > The Garage > AMC 6 Cylinder Engine Repair and Modifications
  New Posts New Posts RSS Feed - 258 oil light comes on briefly, rarely
  FAQ FAQ  Forum Search   Events   Register Register  Login Login

Click for TheAMCForum Rules / Click for PDF version of Forum Rules
Your donations help keep this valuable resource free and growing. Thank you.

258 oil light comes on briefly, rarely

 Post Reply Post Reply Page  12>
Author
Message
Pdok View Drop Down
Supporter of TheAMCForum
Supporter of TheAMCForum
Avatar

Joined: Apr/03/2011
Location: Alabama
Status: Offline
Points: 1021
Post Options Post Options   Thanks (0) Thanks(0)   Quote Pdok Quote  Post ReplyReply Direct Link To This Post Topic: 258 oil light comes on briefly, rarely
    Posted: Nov/29/2022 at 7:58pm
OK, 1976 Grem. stock bottom end on 258, 55K original miles, normal service history, no heavy usage, no noticeable oil leaks/burning. Engine is clean, regular oil changes, I've been inside the oil pan to change the gasket, no debris or buildup. Oil pickup was secure as of about 5K miles ago anyway.

Very occasionally, the oil light will flick on for 2-3 sec, then turn off.

It happened about 2 years ago in a descending, tight right-hand turn coming off a cloverleaf exit at about 15mph. Light was on for 3 sec, and went off after the turn stopped basically.

Today, it went on on a slight downslope, while I was braking to a stop around 10mph, same thing, light went out right as I stopped.  I was very gently applying the brakes, hardly enough to feel since I had coasted most of the way to a stop already.

I understand that the oil is sloshing forward and away from the pickup tube, as a possible cause of this.

However, I don't want to overlook something else, if there's any thoughts out there on what else could be a concern here.

Also, I'm wondering if there's any sensible mods (like baffles) that "should" be done. Sensible = not buying a $500 Milodon pan.
76 Grem X 258/904,4.0 head/MPFI, Comp X250H cam, Hughes springs, Clifford header, serpentine swap.
Back to Top
Pdok View Drop Down
Supporter of TheAMCForum
Supporter of TheAMCForum
Avatar

Joined: Apr/03/2011
Location: Alabama
Status: Offline
Points: 1021
Post Options Post Options   Thanks (0) Thanks(0)   Quote Pdok Quote  Post ReplyReply Direct Link To This Post Posted: Nov/29/2022 at 7:59pm
Oh, and I do not have a pressure gauge installed. That may change, after this issue.
76 Grem X 258/904,4.0 head/MPFI, Comp X250H cam, Hughes springs, Clifford header, serpentine swap.
Back to Top
Midnight Rambler View Drop Down
AMC Addicted
AMC Addicted
Avatar

Joined: Jan/17/2011
Location: SoCT
Status: Offline
Points: 1670
Post Options Post Options   Thanks (0) Thanks(0)   Quote Midnight Rambler Quote  Post ReplyReply Direct Link To This Post Posted: Nov/30/2022 at 2:14pm
I can't speak to the 258s but have seen a lot of oil pressure sensors go bad on the 4.0s.  When my Jeep started to show little/no pressure on the gauge that's the first thing I checked and exactly what it was.  It was intermittent/periodic, and seemed to occur decelerating off the gas or while at idle.

'66 American 440 Convertible 290/M-40/AMC 20 3.15/PS/PB
'04 Jeep Wrangler X Rocky Mountain Edition 4.0 5sp
Back to Top
ramblinrev View Drop Down
Moderator Group
Moderator Group
Avatar

Joined: Dec/28/2008
Location: Wisconsin
Status: Online
Points: 11468
Post Options Post Options   Thanks (0) Thanks(0)   Quote ramblinrev Quote  Post ReplyReply Direct Link To This Post Posted: Nov/30/2022 at 8:46pm
Change the $10 sensor. If it still comes on, put a real gauge in it so you know what the pressure is on that nearly 50 year old engine!

74 Hornet Hatchback X twins (since 1977)
62 American Convertible (still worth the $50 I spent in 1973!) AMCRC #513, AMO #384
70 AMX 360 4-speed (since 1981)
Back to Top
Pdok View Drop Down
Supporter of TheAMCForum
Supporter of TheAMCForum
Avatar

Joined: Apr/03/2011
Location: Alabama
Status: Offline
Points: 1021
Post Options Post Options   Thanks (0) Thanks(0)   Quote Pdok Quote  Post ReplyReply Direct Link To This Post Posted: Nov/30/2022 at 9:19pm
It's just a baby...

OK, I'll swap the sensor and see.  I can't always replicate the issue, even when I'm doing the same maneuver on the same curve near my house.

The gauge is a must, I agree.  I've been putting off gauges until I had an idea how to put them somewhere that didn't look too hillbilly.  Band clamp around the steering column isn't my thing. Ah well.

76 Grem X 258/904,4.0 head/MPFI, Comp X250H cam, Hughes springs, Clifford header, serpentine swap.
Back to Top
ramblinrev View Drop Down
Moderator Group
Moderator Group
Avatar

Joined: Dec/28/2008
Location: Wisconsin
Status: Online
Points: 11468
Post Options Post Options   Thanks (0) Thanks(0)   Quote ramblinrev Quote  Post ReplyReply Direct Link To This Post Posted: Nov/30/2022 at 9:26pm
I agree...just a baby at 55k!
My '74 258 with 180K still has excellent oil pressure! (And I have a gauge that was on the car when I bought it at 42k. But I also have the correct Rally Pak oil/amp gauges I hope to install one day)


74 Hornet Hatchback X twins (since 1977)
62 American Convertible (still worth the $50 I spent in 1973!) AMCRC #513, AMO #384
70 AMX 360 4-speed (since 1981)
Back to Top
Pdok View Drop Down
Supporter of TheAMCForum
Supporter of TheAMCForum
Avatar

Joined: Apr/03/2011
Location: Alabama
Status: Offline
Points: 1021
Post Options Post Options   Thanks (0) Thanks(0)   Quote Pdok Quote  Post ReplyReply Direct Link To This Post Posted: Nov/30/2022 at 9:34pm
Since I tend to think super low oil pressure would have caused issues more often, I'll do the sender swap, and the gauge too just for diagnostics.

What's it, like 5, 7 psi where the light comes on? Something like that, or maybe that was my Buick.

Oh, and I have seen the inside of the pump, virtually new looking 5K+ miles ago. So OK, maybe sender is it.
76 Grem X 258/904,4.0 head/MPFI, Comp X250H cam, Hughes springs, Clifford header, serpentine swap.
Back to Top
Pdok View Drop Down
Supporter of TheAMCForum
Supporter of TheAMCForum
Avatar

Joined: Apr/03/2011
Location: Alabama
Status: Offline
Points: 1021
Post Options Post Options   Thanks (0) Thanks(0)   Quote Pdok Quote  Post ReplyReply Direct Link To This Post Posted: Nov/30/2022 at 9:37pm
OT, but I like the rally pak idea, not sure how my sporty bench front seat would do with no console, but maybe a similar pod or something.

I even thought about A-pillar, but the plastic up there is fragile.
76 Grem X 258/904,4.0 head/MPFI, Comp X250H cam, Hughes springs, Clifford header, serpentine swap.
Back to Top
Midnight Rambler View Drop Down
AMC Addicted
AMC Addicted
Avatar

Joined: Jan/17/2011
Location: SoCT
Status: Offline
Points: 1670
Post Options Post Options   Thanks (0) Thanks(0)   Quote Midnight Rambler Quote  Post ReplyReply Direct Link To This Post Posted: Dec/01/2022 at 9:35am
Originally posted by Pdok Pdok wrote:

Since I tend to think super low oil pressure would have caused issues more often, I'll do the sender swap, and the gauge too just for diagnostics.

What's it, like 5, 7 psi where the light comes on? Something like that, or maybe that was my Buick.

Oh, and I have seen the inside of the pump, virtually new looking 5K+ miles ago. So OK, maybe sender is it.


I do understand that frantic feeling when the light comes on or the gauge drops.Wink

'66 American 440 Convertible 290/M-40/AMC 20 3.15/PS/PB
'04 Jeep Wrangler X Rocky Mountain Edition 4.0 5sp
Back to Top
wittsend View Drop Down
AMC Nut
AMC Nut


Joined: Apr/15/2020
Location: California
Status: Offline
Points: 413
Post Options Post Options   Thanks (0) Thanks(0)   Quote wittsend Quote  Post ReplyReply Direct Link To This Post Posted: Dec/01/2022 at 12:20pm
The light is triggered by the sender grounding to the engine. There is a possibility that when you are in turns, descending a hill etc. that the wire is moving slightly and grounding. Start the engine and carefully wiggle (remember there are fans and belts turning) the wiring around and see if the light comes on.

Not familiar with you oil level tube/stick. Some have a rubber seal and if that is worn, missing the stick goes deeper into the pan and the oil level reads higher when in reality it is low.

A number of years ago when doing an engine swap I had similar symptoms. KNOWING I had put 5 Qt's of oil in I trusted my recollection more than the dip stick. I had to bent the tube for clearance and figured any inaccuracy was how the stick meandered through the tube - now. I eventually drained the oil and around 3 Qt's came out??? THEN, I remembered I only put 3Qt's in to test for leaks the oil pan I needed to indent for clearance  and not the full 5 Qt's I was sure I used..., - but didn't.
'63 American Hardtop
Back to Top
 Post Reply Post Reply Page  12>
  Share Topic   

Forum Jump Forum Permissions View Drop Down

Forum Software by Web Wiz Forums® version 12.03
Copyright ©2001-2019 Web Wiz Ltd.

This page was generated in 0.156 seconds.
All content of this site Copyright © 2018 TheAMCForum unless otherwise noted, all rights reserved.
PROBLEMS LOGGING IN or REGISTERING:
If you have problems logging in or registering, then please contact a Moderator or