Replace engine light came on, but only once.

[Pretty much broke]

This scared the hell out of me, I was on my way to work when I look and the death light is on, and stayed solid. I promptly brought it to a friends house who was nearby to look things over and do a self diagnostic. But the light never came back on and there were no new codes.... I thought I had fixed the misfire issue but its back, but didn't run any different than the usual stumbling and hesitation when the light came on. I cut a hole in one of my cats today to see the condition internally, which was bad, and I'm wondering if somehow these could be connected? (I didn't re seal it and most of the exhaust on that side is coming out there, not the brightest idea I know) I had never seen that light come on driving. Only other time I'd seen it come on was when I forgot to plug in the map sensor. The car has some wonky electronics and most of it is original. But that light still scared me. I drove it another 20 minutes to work and then let it idle and revved it a bit, and it didn't come back on. I have an itching feeling the dizzy I put in isn't a steel gear after all, but I think I would have ate it by now. I do have a good amount if oil leaks so maybe Im losing pressure that way, there's always some burning off the drivers side cat. Any ideas of why this may have happened otherwise would be greatly appreciated.

[gadget73]

The only thing the red replace engine light comes on for is overheating or loss of oil pressure. Or one of the wires to either sensor grounding out. The one down to the oil pressure sensor gets close to the exhaust, so have a look at that for damage.


If its the amber light, thats different. Its a computer code thing. Its not smart enough to know anything about the converters though. Check it for codes and see what that has to tell you.

[Pretty much broke]

I checked for codes again, Same 2 I've always had. I would think at 99k oil pressure wouldn't be an issue. It doesn't even valve clatter on start up like my 4.9 f150 did. The car is extremely quirky with its electronics, the blinkers act like a bulb is out, you have to play with headlight switch for the dash and taillights to come on, the headlights frequently dim out of nowhere, etc etc. I'm hoping it's just a sender. It doesn't make any noise running at all other than the alternator which sounds like a blender full of rocks and surely needs replacing.

[Pretty much broke]

Drove it about 20 ft down the road after work, light came back on. Got it home and checked the codes with that light on, no new codes. Oil smells fine, coolant was Luke warm at best. Pulled a plug which had chunks of either carbon or something along those lines. Looks like its running rich. About to pull the dizzy to check the gear.

[Pretty much broke]

Pulled the dizzy, which was in fact steel and in perfect condition. All plugs look normal and or rich except the rear on the passenger side which was slightly hot. Not sure what's wrong with it, but it may be the end of its life sooner or later. Move on to a P71 if I can't figure this out soon. As usual. Any advice is greatly appreciated

[Mike_Windsor]

I would presume that it's an electrical fault somewhere, as Gadget73 indicated.

Perhaps you have low oil pressure due to a clogged pickup in the oil pump?

[Pretty much broke]

I thought the same with the pickup, I have been running it much harder than normal these past few days and may have broke some stuff loose. The light comes on 3-5 seconds after starting now regardless if its being revved or idling. Engine sounds normal other than the unholy thing that is the misfire I can't seem to diagnose. Pulling the dizzy revealed a lot less sludge than there was previously from what I remember. It runs the worst under light load in OD and the best when at 4-5k. Slight to no missing at all when it's getting pushed hard.

[pantera77]

Only two things throw the death light, low oil pressure, or overheating. If it's not overheating, and you have good oil pressure, then wiring or sending units.

As for the headlights, check the connection at the headlight switch and the MFS, there notorious for burning up there.

If the alternator is failing, time for a 3g swap.

[Pretty much broke]

I'll have to get ahold of another pressure gauge to check pressure, seriously hoping its electrical, because there's no way I can pull the engine to clean the pickup. Looking at the sender it is completely plastered in oil, so bad connection hopefully. But don't have my hopes too high. Even if I cure the light I've still gotta find the misfire. I wish I had the means to pull the engine, because I would have a long time ago. Any tips on cleaning pickup without pulling? Run the pump backwards somehow maybe?

[Hearsesrock427]

If you were overheating, I'd expect there to be plumes white smoke at some point. Or at the very least some coolant expansion and overflowing. Especially since you said you were running it very hard. That's basically a stress test for your cooling system. And the thing just kept chuggin' along, like it was nothing. If something was wrong with your cooling system, you can't beat on your car for very long. You'll create a smoke show in a matter of minutes, if even that. Ask me how I know.

I'm convinced this is oil pressure sending unit/wiring/electrical related. Now's the time to install aftermarket oil pressure gauges if you're interested.

[Pretty much broke]

Found the pressure sender. Its the little tiny thing not the bigger cylinder looking one. Cleaned the connections on it but haven't removed it yet. Crossing my fingers

[Mike_Windsor]

I'd like to err on the side of caution here and recommend not firing the engine up unless you absolutely must. If it is oil pressure failure you're just gonna destroy the engine; there might be some (dim?) hope that, if this is the case even, that it's not beyond rescue...

[miamibob]

If the engine sounds good and performers well, I would think it is sensor/electrical in nature.

[85crownHPP]

Why are you checking for codes? The red 'engine' light has nothing to do with the ECM.
The amber CEL comes on in response to a code, and typically has nothing to do with oil pressure or temperature.

Which one is it?

[Pretty much broke]

I checked the codes because I know Jack about obd1 cars, I'm all trial and error, mostly error. It seems to run just fine and after cleaning the contacts on the sender it shut the light off for about 5 minutes and then blinked like crazy and stayed solid. The wire leading to it has been taped multiple times and the connection Isn't amazing , I ordered a new one and a socket though. Ive essentially thrown caution to the wind with this engine, it sounds fine and seems to run like it did before. My main goal is to get rid of the horrible hesitation and miss that it does. Its driveable but pretty horrid. Ive thrown a good amount of parts at it which haven't made a difference. IAC, TPS, coolant temp sensor, distributor and module, plugs and wires, coil, EGR valve, etc etc. I was going to do a new exhaust on it because Im sure the thing can't breathe with 4 original cats going into 1 pipe but I'm hesitant because if it doesn't help it would be a big waste of money. One of the o2 sensors is also original. Im trying to narrow down the list of what could be wrong. As I said before, runs best under medium-heavy load and runs the worst at light load especially in OD. And no real surprise, but I'm getting 200 miles to a full tank, if that helps at all.