I have several problems in a new-to-me '89 F-150 I6 5 speed with 86,000 miles on it (OD) that needs help. I bought a Clymer manual for help and it was useless. Hope you can help.

When running, a dash light that says something like "Rear Antilock Brakes" is lit. Is this bad? What does it mean?

The dash oil pressure guage shows zero pressure. But the engine seems to run fine. I cannot find the oil pressure sensor on the I6 engine. Where is it? Can you suggest some tests for the sender and the rest of the circuit up to the dash oil pressure guage?

There is a gurguling swishing noise (like water being forced through a small pipe in a swimming pool) coming from the transmission. If I am stopped in neutral and the clutch is depressed, there is no noise. If I am stopped in neutral and I release the clutch, the noise starts. If I am driving the noise is present except when I depress the clutch to shift. When I depress the clutch the noise stops. What is going on? It can't be the throw out bearing cause that would make noise when the clutch is depressed, right?

The owner's manual says the 5 speed manual trans takes ATF!. I have not been able to find a dip stick to measure the amount of ATF in the tranny or a way to add some if needed. Any suggestions?

I looked under the truck at the tranny and found that the rear half of the tranny is wet with oil. How bad does all this sound? Are there any tests I can do to figure out what is going on?

With hope in my heart that these symptoms are not terminal (not worth fixing) I thank you all for any help you give me.

Thanks

 

The anti lock light means there is a problem with the rear abs system. It may be the speed sensor on top of the rear axle, or the RABS valve are the most common problems. The oil pressure sender is above the oil filter. It has a single wire coming off it. If you want to verify oil pressure, you need to remove the sender and install an oil pressure test gauge, or an old aftermarket oil pressure gauge with the plastic tube. You could just install an aftermarket gauge, but do not use the plastic tube, it will eventually break. There is a 1/8 inch copper line kit which is the best. If the leak on the tranny is at the very rear, it is probably the output seal. If it is from the top, it is from the three black plugs that fill the shift rail holes in the rear of the shifter assy. You can get them from the dealer only. You need to check the oil level in the trans. There is a fill plug and a drain plug on the passenger side. Remove the fill plug(the top one, it will take a 15/16 inch wrench to remove. Fill with atf until it runs out of the plug and install the plug. You're probably hearing gear rollover noise. Some noise is normal. When you push the clutch in, you are disconnecting the trans from the engine. Hope this helps,

Robbie

 

Thanks for the reply.

That tranny noise sounds like fluid slushing around. I never heard gears sound like that!

You have given me something to start with.

Thanks

 

For the oil pressure problem - To verify that the wiring and gauge are ok you can disconnect the oil pressure switch connector and jumper it to ground (the wire going to the vehicle, not the switch), and with the key on the gauge should show pressure. If it does then you know the wiring and gauge are good and either the oil pressure switch is bad, or you have less than 4 psi of oil pressure which is unlikely if it is still running and not knocking.

-Jon

 

double post

 

My old truck has an oil pressure guage not an idiot light. Will I risk damaging the oil pressure guage with this test?

 

It's not really a gauge, it's an idiot light in disguise. If the engine has above 4 psi oil pressure it will read in the normal range, below 4 psi it reads no oil pressure.

-Jon

 

Yahoo! A little Sun mechanical guage shows 50# pressure at idle. Don't know if it is accurate but it does show significant pressure.

One problem down and the rest are yet to go.

On the transmission front the prior owner and his father said they changed the tranny oil for some stuff dad had at work. He works for a heavy equipment company and apparently used some heavy duty oil. Well, they decided it was too thick and drained some out and put in some thinner stuff. Not exactly what Ford intended. Now it must be flushed and re filled. I do not know the proper way to flush the tranny. I suppose I should drain the stuff they put in and fill with ATF then run it for a while, drain it again and fill it with MERCON. I hope they did not destroy the tranny. Any suggestions?

Thanks for your help.

 

Do the drain and fill a few times. The trans only hold about 3 1/2 quarts total. Buy a case of dexron III and use it all. Drive it about 5-10 miles before draining, and drain immediately after the drive. The fluid will be hot which will drain the most fluid.

Robbie