Engine Light (On & Off)

Reply

  #1  
Old 07-10-03, 08:10 PM
Member
Thread Starter
Join Date: May 2000
Location: las cruces.new mexico,
Posts: 32
Question Engine Light (On & Off)

78 Cutlass 3.8, 125000 miles
The engine light comes on only after a few miles of driving. Then only at idle then goes off when i accelerate or pickup the RPMS in park.
I know the idiot light is for oil pressure.
So do you think the oil pump is giving up?
2000 miles on last oil change.
Are these pumps a do it yourself job?
Have a factory manual but need to get it out of storage.

Thanks!
 
Sponsored Links
  #2  
Old 07-10-03, 08:47 PM
Visiting Guest
Posts: n/a
if this is a "buick" v6(very likely) then the oil pump is mounted outside the engine---very easy to replace, these pumps have been known to wear out on old things like this, especially with an aluminum body and steel gears. just get the car safely up on ramps and look at the front timing cover, it's that boxy looking thing hanging down on the passenger side that i think the oil filter is mounted to. save yourself some trouble and use a heavier weight oil for now....
 
  #3  
Old 07-11-03, 06:13 AM
darrell McCoy
Visiting Guest
Posts: n/a
check oil press. manually. If it is reading low then you have one of 2 things, weak oil pump or failing bearings.
 
  #4  
Old 07-11-03, 06:32 AM
Joe_F
Visiting Guest
Posts: n/a
Thumbs up

Both posters are correct.

Original poster: You could have a low idle condition, a bad oil pressure switch or internal engine failure. With that mileage on an old "LD5" 231, you are on borrowed time.

Check the oil pressure with a reliable hand held gauge. Autozone can rent you one. Likely you do have a worn oil pump. The front cover may be need to be replaced too as they wear out from this problem too.
 
  #5  
Old 07-11-03, 01:23 PM
knuckles
Visiting Guest
Posts: n/a
These engines are notorious for oil pump failures.

Too often, mechanics will replace the oil pump without replacing the oil pump pickup, which is usually the reason the oil pump failed in the first place.

These engines use a very fine mesh on the oil pump pickup screen. This mesh clogs w/ sludge over time. The screen also has a built-in bypass, but it usually sludges over & fails to open.

IMHO, the best way to repair this problem is to remove the oil pan FIRST and inspect the connecting rod & main bearings. If they're OK, go ahead & replace the oil pump pickup. Clean the oil pan thoroughly to remove any sludge before you install the pan.

Next, address the oil pump. There are several types of oil pump repair kits available for these engines. A complete cover assembly is the best repair, followed by the High Volume gear/spring kit, followed by the standard volume gear kit with wear plate.

The standard gear kit can be installed with the cover still in the car. The other two options require removal of the cover.

Assuming your bearings are good (they should be if you haven't been driving with the oil light on for a long time) this is a pretty simple repair job. You should be able to complete it in an afternoon. Dig up your repair manual & have at it.

A few pitfalls to look out for:

The exhaust crossover pipe must be removed to drop the oil pan. Make sure you soak the bolts in PB Blaster overnight before you attempt to remove them.

The water pump bolts and front cover bolts tend to corrode, especially if the cooling system has been neglected over the years. Patience, PB Blaster & a wire brush will usually get these out without breaking them.
 
  #6  
Old 07-11-03, 01:56 PM
Member
Thread Starter
Join Date: May 2000
Location: las cruces.new mexico,
Posts: 32
OK: Hooked up a oil pressure gauge. Get 37-40 at idle then goes down to
almost 0 psi as car gets to temp.
Knuckles thanks for the info. on the kits for the oil pump. Man! droping the oil pan is going to be fun!
Were can i get the kits for the pump?
Should any parts store have them? Also is there a way to get the idiot light to go off with out taking out the bulb?
 
  #7  
Old 07-11-03, 02:00 PM
Joe_F
Visiting Guest
Posts: n/a
Yes, any auto parts store will have the parts. They are common items.

Fix the problem and the light will go away .
 
  #8  
Old 07-11-03, 04:16 PM
Member
Thread Starter
Join Date: May 2000
Location: las cruces.new mexico,
Posts: 32
Joe now that i have a gauge and sender hooked up the OEM wires are disconnected from the pressure switch and the light stays on. Would a jumper wire between the two connections on wireing harness that went to the switch work?
 
  #9  
Old 07-11-03, 04:25 PM
knuckles
Visiting Guest
Posts: n/a
Dropping the pan is actually very easy once the crossover pipe is off.

Simply remove the motor mount through bolts & jack up the engine. Place small blocks of wood between the mounts & frame brackets, then remove the jack so you can get the pan out.

As for the idiot light...it'll go out on its own once you repair the oil pump problem. I suggest you DO NOT drive the car until it is repaired to prevent damaging the bearings.
 
  #10  
Old 07-11-03, 05:20 PM
Joe_F
Visiting Guest
Posts: n/a
Thumbs up

Knuckles is correct.

I used to own an "LD5" 231 V6 1979 Cutlass---paid 900 bucks for it in 1985 (between selling our old 1974 Duster and the cost of this car) and sold it for 700 in 1993.

Never failed us once. The 231 is a lackluster engine which has oil pressure problems as mentioned.
 
  #11  
Old 07-12-03, 12:10 PM
billys68ss's Avatar
Member
Join Date: May 2003
Location: USA
Posts: 1,459
I have several of these engines. One in particular (in a 1984 Buick Regal) had similar symptoms as you have described here, except mine actually started knocking before I realized anything was wrong. Upon tearing down the engine for rebuild I found that the reason the oil pump had failed was because the fiber timing gear has desintigrated and had only a few teeth left. The chain never gave way, but now that I think of it, I am sure that is where the knocking noise was coming from. Anyway, the little bits of the timing gear found thier way into the oil pump and locked it up. I would strongly suggest replacing the timing chain and gears while you have the cover off.
Hope this helps,
Billy
 
Reply

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Thread Tools
Search this Thread
Display Modes