Hey Guys, I'm Andy from OKC. I just bought a 92 F-150 Ext cab, just to have a beater to get me from A to B.

The truck has the 302 in it, and it has a few problems I was wondering if I could get some input on.

The truck burns a little oil, and when I say a little I mean more like a lot. When I first start the truck up, it gives a pretty good puff of oil smoke. It occasionally smokes a bit on hard accelerations too. The oil guage stays at the lower end of Normal, but does go up a bit on the highway. Im wondering if its just a valve job that needs to be done, or if it could be something else. And if it is just a valve job, what all does that take, or how much would a shop charge for it?

It also stalls once right after its started when its sat for a while. I can restart it, and the idle will climb up to about 2500, then it calms back down. Any ideas on this one???

I also have what sounds to be like a bubbling noise coming from under the pass. side of the dash. I think this might just be the heater lines that need to be bled, or could it be something else?

Thanks a lot in advance for the help!
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First of all, Welcome to the FTE site. There is a lot of valuable info. here.

1) There are some really good engine guys on here that can help you with this one.
2) The 2500 RPM's sounds a little high. Typically what I see is on initial startup, it idles up to about 1500 and then kicks down to around 900 and then to around 700. How many miles are on it?? Could need the throttle body cleaned. I think you use throttle body cleaner for this and not carb cleaner. While your cleaning your could also clean the IAC (Idle Air Control) valve that is bolted on the side of the throttle body, clean the valve body and not the electrical part. You could also check the TPS (Throttle Position Sensor) with a DVOM (Digital Volt Ohm Meter). I think the search function is operational again, so you could search by TPS or Throttle Position Sensor and I am sure you can find the exact procedure for checking this. I think it is supposed to read .9 Ohms, but if I am wrong someone will correct me I'm sure. I don't mean that in a bad way either.
3) The gurgling may just be air in the system. Take off the radiator cap, turn the heater on with the fan on high, get it up to normal oper. temp and top off the radiator 'til you get it full.
4) Might want to invest in a Chilton or a Haynes manual. You'll probably need it.
5) If you go to Autozone's website on the left hand column below shop on line there is a Repair Info category. You just put in truck info. and it will bring up chapters from either Chilton or Haynes manuals.

Good luck and post back,
guzzler96

 

Hi And Welcome.
The oil guages in these trucks is little more than a fake idiot light. You'll need to install a real oil pressure sensor and guage if you want to monitor that system as the one from the factory will read someplace in the normal range (usually in the low end, by the n or o) as long as there is any pressure; or you can do the conversion which will read better. you simply replace the oil pressure sending unit with a thunderbird unit, and bypass the resistor on the back of the cluster. Then you have an inaccurate "rule of thumb" gauge. It will move with the oil pressure, but not indicate PSI or anything.


Also there is a pcv valve tubing reroute suggestion that may help you also. Do a search on PCV valve. The thread you want will be named the same.

Good Luck,
Popa Tim

 

Thanks a lot guys, I'll make sure to check out all the things you said. I went and spent about $90 on tune-up stuff last night, so the truck should get a pretty decent going over tonight.

As far as the stalling, I tested the alt. and when the truck is warm idling, it's only putting out 48 amps, which seems really low to me. I'm pretty convinced that the truck dying is a voltage prob. The guy I bought the truck from said the alt. was fairly new, but that doesn't rule it out.

What are the specs for my alt? The truck is a 92, has the 5.0, 2wd, and about 138k on the odometer. I'm used to the GM I had which ran closer to 80+ at idle, you guys also suspect a problem with the alt?

 

Alternators do not always put out their full rated power, only enough to put out about 14 volts. The voltage is regulated and fixed, the amperage to keep it there is variable.

 

Right, but it seems to me that this one isnt putting out as much as it should. The voltage meter sits towards the low end of normal. The battery tested about 650 CCAs, so i think its fine. Any other suggestions?

 

Try testing the voltage across the battery terminals as it idles with accessories all off and then again with them all on. If you see 14v or so, at least with everything off, the alt is good and the gauge is bad. I have an old '91 with an I300, with what I think is only a 65a alternator. It gives me just shy of 14v at idle with everything off and that drops to about 13 with everything on at idle. There may be something wrong with the alt though, I have never tested it.

The bottom line is that if you can see 14v at the same time as the gauge reads low then there's something wrong with the gauge and you're fine. Otherwise, take the alt off and take it to an autoelectric place and have them test it, optimally with an oscilliscope so they can see what each set of windings is doing. They can tell you if there's something wrong with it. If that's not it and you are STILL having problems, check the wiring between the alt and the battery, a lot of times the wiring connector on the alt gets really crappy. You can buy a replacement connector at most any parts house and splice it into the harness.

 

I live in OKC also whereabouts are you at?

 

Im on the north side, around Hefner and Council.

I'd have to say that the guage isn't the problem. By the fact that the lights are extremely dim, and sometimes do not kick on until the rpms get up a bit, Id say there is a def. elec prob. somewhere.

I am kind of thinking the brushes in the alt. are bad. I might just see if I can find an alt out of a 95-ish Mustang, which are rated at 95 amps, as opposed to my 60, I believe. I do have a new stereo/amplifier and an alarm to install on the truck, so if this is causing me problems now, adding that stuff on will just make it worse.

Thanks again for the help.

 

Andy,
You can't trust these dash gauges. Check the voltage across the battery with a voltmeter.

Another thing to note is that bad grounds & battery wires are quite common in thses trucks. It is suggested you clean your Battery posts, chassis ground on radiator support in front of battery, PCM ground near left hood hinge, engine block, frame. These you should probably do even if you do change the alt.

Keep us posted on what you find :-)
Popa Tim

 

Thanks for that info Tim, I didn't know these trucks had those probs. I would hate to think that a new alt. would be causing this. I'll check out all the points in the system.

Thanks again.