Confused.....upset....scared?!?

gldnedge · 05-13-2005, 02:16 PM

I've had this '78 SC for a little over a month now and have only gone on a few somewhat "spirited" drives on a nearby winding road. Most of the time it's just an around town car and transportation to work. Anyhow....

This afternoon I decided to take a quick jaunt out that little road close to my home before attacking the honey-do list. Went out a few miles, turned around and drove back home. At no point was I pushing the car too hard or doing anything silly....just running her around 4-5K throught the twisties.

On the way back I noticed the temp coming up....9:30-10:00 on the gauge. Then I noticed the tach slightly surging upward a little when I upshifted. After that I felt a loss of power and the engine began to feel kinda shaky/wobbly. By the time I limped it home and into the driveway the engine would actually shake the car at idle. I let it sit for a minute at idle, then turned it off.

The car has fresh oil, correct ignition timing, brand new plugs and I feel as if the air/fuel mix is very close to being ideal. What in the heck could be causing this to happen? For the record, it did the same thing a couple weeks ago and was just fine after cooling down.

Do my symptoms sound familiar to anyone? *Gasp* Am I looking at a rebuild already?

BTW, I had great oil pressure until the car started acting goofy...then it dropped like a rock.

I'm confused and a little upset all at the same time. Did I buy a lemon or am I just missig something obvious?

Any help would be GREATLY appreciated.

Aaron

ubiquity0 · 05-13-2005, 02:25 PM

Quote:

Originally posted by gldnedge

BTW, I had great oil pressure until the car started acting goofy...then it dropped like a rock.

What oil pressure readings were you getting before & after?

How about oil level?

FrayAdjacent911 · 05-13-2005, 02:25 PM

I think you'd want to find out what the problem is before you cringe in fear of a rebuild....

jester911 · jester911's Garage

Make sure your fan belt is turning the fan. If not do not drive it.

RANDY P · RANDY P's Garage

sounds like oil aeration - but I'm not familiar enough to know if that's the problem with these.

Doesn't it drool out the top and get into the CIS?

TerryH · TerryH's Garage

Thermostat stuck?

gldnedge · 05-13-2005, 02:31 PM

Ubiquity-

My pressure was around 5 bar under throttle before it dropped. Idle pressure around 3 bar.

Oil level is half way between the min and max on the dipstick. Level gauge needle is in the middle.....but I noticed it creeping up when all this was going on. I just changed the oil about 20 miles ago and feel good about the level.

Is a vapor lock a possibility? Even though I think the timing is correct, could I have goofed and caused it to get too hot in there?

Aaron

gldnedge · 05-13-2005, 02:33 PM

Fan is turning....no problem there.

Not sure of the thrmostat sticking....don't have the problem when I'm driving around town.

Aaron

RANDY P · RANDY P's Garage

next time it acts up feel around the front cooler loop (careful, it should be hot)

If it isn't it's sticking.

ubiquity0 · 05-13-2005, 02:36 PM

When you say oil level is 1/2 way between upper & lower marks you mean when the engine is idling & fully warmed up right?

Just checking.

juanbenae · juanbenae's Garage

can you describe you proceedure for checking the oil?

lateapex911 · 05-13-2005, 02:43 PM

5 bar and 3 bar are fine..actually 3 bar is more than fine, I think. But what about hot? What then? And did the pressure drop all at once?? Or was it gradual. Something seems fishy here...

Bill Verburg · Bill Verburg's Garage

It's amazing that after 25 yrs the same old issues continue to crop up.

The '78 -'79 SC was notorious for it's oil problem. The problem was in hard driving oil would accumulate in the crankcase. then fix itself after a while by scavanging the excess oil back to the external tank.

This may or may noyt be your problem but it sure sounds familiar.

The fix;
1 oil screen 930.107.314.00
1 oil pressure relief spring 930.107.531.01
1 guide for spring 930.107.533.00
1 screw plug 999.064.016.02

this was all detailed in a factory bulliten dated 7/12/79

engines prior to
640.0025
630.8027
630.0211
630.9024

all need thiese parts

M.D. Holloway · 05-13-2005, 02:47 PM

When you say the temp was going up, what was the temp before and after?

I may have a lil sump'n that could help you out - you running 20W50 or 15W40?

BRink · 05-13-2005, 02:50 PM

I don’t want to give too much false hope, but I had the exact same problem with my car.

After months and months of this issue I just happened to take the main vent line from the oil tank to the back of the engine off. For some unknown reason the PO plugged the oil tank line with a rubber stopper and put the hose back on.

I don’t know exactly what was happening inside the engine, but it did shake violently and seemed to run on 5 cylinders until it cooled down.

Also, check the sump plate to make sure the plate didn’t get turned around and is blocking the oil pump pickup…

Best of luck,

gldnedge · 05-13-2005, 02:53 PM

Gave the car 40 minutes to cool off....then drove it down the street to see what it felt like. Here's the details:

Started up a little rough, but smoothed out in about 30 seconds.

Normal driving at 3K rpm I was showing 4 bar, 1bar at idle. Temp was normal (below 9:00).

Pressured up to 5 bar under throttle as it always does.

No funny backfiring or engine surging. Everything is normal as long as I don't drive it hard for any length of time.

Aaron

Zeke · 05-13-2005, 02:55 PM

Back to the resulting *damage* (if any). Did you do the simple things like checking for loose plug wires? Loose plugs? That happened to a board member a couple days ago.

Not that a loose wire sould make the temps go up, but at least eliminate the simple stuff before worrying about a rebuild.

gldnedge · 05-13-2005, 03:06 PM

I'll try to answer everyone at once

I'll check to oild cooler the next time this happens. But that won't be today.

My oil checking is only done with engine running (after warmed up) and on flat ground.

I'm running 20W50 oil (Valvoline) as of 20 miles ago.....before that it was 10W40.

Car consistently runs 4 bar when cruising and 5 bar under throttle. That is, until I get into the pedal for a while, then (like today) it drops like a stone.

Bill V......Thanks, and all parts have been noted. Sounds like you've seen this before. I very well may do exactly as you say.

Brian.....I sure hope there's not a plug in my oil line. I believe the sump plate is installed properly as i just looked at it the other day.

Milt....Plugs are snapped in tightly. That was the first thing I looked at.

Aaron

gldnedge · 05-13-2005, 03:12 PM

Everyone-

First of all....thanks for the quick ideas and help.

Should I take the car out again for a spirited drive (which results in all this crapola) in order to try to figure out what's going wrong?

I don't hink there's any damage done as the car seems to recover after sitting for a little while.

Aaron

Jay Auskin · 05-13-2005, 03:24 PM

Check your timing and dwell. My points were way off (I don't think the screw was tight), and it threw my timing off. I compensated with the distributor. My car ran like sheat when warm, and the oil temps were high...mind you, my timing ended up waaayyy off. It's an easy 1 minute check, but it's something to consider. After a few hours of futzin' with the points, and afterwards setting timing, it's a new car. Oil temps don't get over 180F in city or highway driving now.

I hope you find the problem soon

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