Tuneman1984

Hello,

First time poster to this lovely forum. Just bought an '89 Escort GT that had been sitting for about 4 years (but started weekly and run up and down the drive).

About half an hour ago after dropping off a buddy, I gave it a bit of a boot up one of our residential streets, getting it up to around 50 MPH and not doing more than about 4000-4500 RPM. Immediately after, the oil pressure light came on, and stayed on except for flicking out a couple of times. Then as I pulled into my street the headlights starting flickering on and off, and continued to do so after I shut the engine off.

I'm not really a mechanic but I wanted to propose a theory. Maybe as I ran the engine up to speed, the oil pump had to work faster and then sucked power from the alternator? Does this sound plausible or am I out to lunch? I'm hoping it doesn't need anything drastic but please do offer any help or suggestions. I'm heading to bed so the car is going to sit overnight now anyways. Thanks in advance!

Bert

Has the oil been chabged lately? I'm sure it's full of oil? If someone had it that hasn't changed the oil often, the screen in the pan could be mostly plugged and not enough oil can get through. If all that is not the case, get a mechanical gauge to hook up to where the sending unit is to see what the pressure is. It could just be a bad sensor.

If the headlight are flickering rythemicaly, the headlight switch needs to be replaced. After time, the contact on the circuit breaker inside gets dirty cintacts and will cause that.

Tuneman1984

Okay, so it could be that both occurences were unrelated. The car just had an oil change yesterday so I'm going to check the oil level shortly before I head out. It was changed regularly by the previous owner, even while it was just sitting. On the last stretch that I drove it (just into my cul-de-sac) the engine started to sound quite rough so it could be low on oil. Wouldn't surprise me if one of the dimwits at my shop forgot to tighten the drain plug...

Bert

Or the oil filter.

Tuneman1984

Oil level is fine and the light hasn't come on all day (driven about 10 miles running errands). One of the shop guys tested the electrical and it looks fine for now; he also cleaned the battery terminals but said that wouldn't be it. I mentioned what happened and how today the revs drop if I put the headlights on, so he thinks the alternator might be on the way out. Does that sound plausible?

Bert

That or a weak battery.

FordMan59

The oil pressure light could also be a bad oil pressure sending unit or a bad/dirty connection going to it. The sending unit is on the firewall side of the engine close to the oil filter. It will have a single wire going to it that just slips onto the end of the sending unit. Check the ground wire for the headlights to make sure it is clean and tight. I had the ground work it's way loose on my '88 Pony once and didn't have any headlights.

Tuneman1984

So I've investigated a little further, as the flickering issue has continued. It's only the low-beam headlights and foglights that flicker out together. If I put the high beams on, the headlights stay on continuously. I'm going to root around later but are there two sets of wires going to the headlight unit? It's a dual-fitment bulb of course so at first I thought it would have been all or nothing. But now it appears I've isolated the problem a bit. Also since the stock bulbs aren't that bright I could drive with high beams on for now since no-one on the road notices.

Any tips would be appreciated as I'm completely new to diagnosing wiring issues like this.

FordMan59

Sorry I didn't think of it sooner, but I've had the same problem with my '88 Pony a few times with the low beam headlights flickering on/off while driving and it was the dimmer switch needed replacing each time. Next time they flicker try wiggling the arm on the dimmer switch and see if they come back on. If they do it's the dimmer switch.