i was driving home from dinner and i never really drove too fast as is, but when im on the highway i cant get above 55 mph without horrible vibration and the car feeling like its gonna fall apart. i noticed that it never reved above 3k rpm. Even in park and neutral the car had horrible vibration if revd up. so im at a light andi reved it up and bam my check engine light came on and oil pressure at dead low. at idle and motion it was 0 pressure. now i know the stock gauges **** but this was bad. i pulled over as quickly as possible, and the car sounded like CRaP. no VALVE tick thank god but it did sound horrible. the car was not over heating and i did a fresh oil change 3/4 weeks ago. I checked the oil and it was still clean and not low...could this just be the oil pump? and why wouldnt my car ever rev past 3k rpm..its an 89 5.8l automatic with a rebuilt motor with 56k miles...thanks guys
wont rev above 3k rpm? then oil pressure GONE!
- Thread starter sylert
- Start date
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Seabronc
New member
It is possible that you have a rev limiter. I'd be concerned about the vibration at the moment. If it does it in Park then it could be a broken engine mount, harmonic balancer, etc. The oil pressure could be the sender, if it is a bad sensor the computer will probably have a code. In any event, you should have codes stored, so pull them. Places like Auto Zone will rent them to you or you can use the manual method of pulling them which id a bit of a pain but doable.
Good luck,
>-
Good luck,
>-I would tow it to the house or a shop to check it out. If you have no oil pressure, any damage has prolly already been done, as a dead oil pump quickly leads to major bearing damage and you'll soon hear the knocking. After checking the obvious like engine mounts, the harmonic balancer and any accessory pulleys for loose/ broken bolts, take a look at the oil filter. Take it off, cut it in half with a hacksaw and check the inside form etal filings. You may find some on the oilpan drain plug if it's a magnetic one, too. While the mystery vibration could also be from a rough idle, the lack of power could also mean there's a problem in the valve train. Things like a stretched, slipped or broken timing belt/ chain or a bad camshaft are all possible. It's likely you'll have to tear into the motor if there's no oil pressure after checking it with a mechanical gauge. JSM84
I've had several 5.8L motors kick the bucket from a dead oil pump. The common cause was a pick-up tube clogged with sludge. Synptroms were loss of oil pressure folloed shortly by a loud knock.
yeah so i towed it hom with a hefty tow rope and a saturn lol and started it at the house and bamm pressure is back!! but engines runnin like doodie sooo probably sludge in the pickup or something blocking it, still parting it out..
the rpm/vibration thing could just be from bad timing, or your timing gear at the bottom of the dist slipped. Ive had the roll pin break on them before. On the 5.8l does the oil run up through the dist shaft?
It could also just be that your timing is off because the dist came loose, and your oil pressure sender is shot. I dont know if this is possible on the 5.8, but if you take the oil fill plug out of the VC is there a baffle in the way? if not you could start the truck and look in the VC and see if oil is getting flung around. you could also pull off an oil line from somewhere and crank it and see if oil comes out.
id hate to think you part it out when its a cheap sensor and timing adjustment.
It could also just be that your timing is off because the dist came loose, and your oil pressure sender is shot. I dont know if this is possible on the 5.8, but if you take the oil fill plug out of the VC is there a baffle in the way? if not you could start the truck and look in the VC and see if oil is getting flung around. you could also pull off an oil line from somewhere and crank it and see if oil comes out.
id hate to think you part it out when its a cheap sensor and timing adjustment.
BroncoJoe19
Active member
I'm with Shift1313 on this.
When the engine was rebuilt, wouldn't he have boiled out the engine block and eliminated any sludge? OK Yeah this was 56,000 miles ago.
How long would it take without any oil pressure for one to hear valve tapping due to hydrolic lifters? He didn't hear any tapping.
You know the guages on our trucks are not really pressure guages. They LOOK like a guage, but they might just as well be a light bulb. A faulty connection to a bulb and it goes out. A faulty connection to what looks like a oil pressure guage, and it goes to zero!
As far as the engine running ******* it could be like he suggested, or even just a bad vacuum leak.
Both are just about free to fix.
Perhaps your truck always ran ******* and you didn't realize it. I had a similar experience with mine, (but after I got it running correctly, I am very pleased). Perhaps that is why you are so quick to part it out. I don't know, but it'd be a shame that another bronco goes down for what may be a simple fix.
When the engine was rebuilt, wouldn't he have boiled out the engine block and eliminated any sludge? OK Yeah this was 56,000 miles ago.
How long would it take without any oil pressure for one to hear valve tapping due to hydrolic lifters? He didn't hear any tapping.
You know the guages on our trucks are not really pressure guages. They LOOK like a guage, but they might just as well be a light bulb. A faulty connection to a bulb and it goes out. A faulty connection to what looks like a oil pressure guage, and it goes to zero!
As far as the engine running ******* it could be like he suggested, or even just a bad vacuum leak.
Both are just about free to fix.
Perhaps your truck always ran ******* and you didn't realize it. I had a similar experience with mine, (but after I got it running correctly, I am very pleased). Perhaps that is why you are so quick to part it out. I don't know, but it'd be a shame that another bronco goes down for what may be a simple fix.
Last edited by a moderator:
Trannie----torque converter....??
BroncoJoe19
Active member
Yeah Matt, Thanks for the response, that's what I was thinking, and the point I was trying to make.
He probably has a flaky oil pressure switch, or bad connection. One would not otherwise have NO oil pressure one day, and normal the next. Also, he had no sign of loss of oil pressure.
He probably has a flaky oil pressure switch, or bad connection. One would not otherwise have NO oil pressure one day, and normal the next. Also, he had no sign of loss of oil pressure.
regarrr
New member
My oil pressure dropped off from time to time on my 87 5.0. Then it stopped all together. It turned out to be the pressure sending unit. If you change the sending unit, be careful not to overtighten it. I overtightened mine and couldn't get it back off later. It turned in to a big headache. Snug is tight enough.
