I have a '96 F-250 PSD. Its my first diesel and Ive only had it about 3 months. I did my first oil change earlier today, at around 2:00. I changed the oil (Rotella 15W40) and filter (Fram?, orange filter). I put in 14 quarts. After that, I started up the truck and drove it up the road and back (probably about 1 mile or so). It was running fine and seemed like all went well. After I checked the oil, it seemed a little foamy. It had very small air bubbles, I assume it was air bubbles atleast. Is this normal?

So after about 5 hours, I went outside to go to the store and when I went to fire up the truck, it did nothing. I turned the key, all the dash lights and stereo went on as usual. I waited for the "wait to start" light to turn off, then turned the key to fire it up. It made no noise what so ever. It was like trying to start the truck without the clutch to the floor.

I immediatly tried it again, it did the same thing. There are no leaks under the truck. Ive had a piece of plywood sitting underneath it that I used to lay on and its completely dry. Also, the oil is at the right level and there is no more air bubbles or foaming. The oil seems fine.

I dont know where to go next. I sure hope this is a minor problem. Any help is appreciated. Thanks in advance!

 

sounds like the safety switch gave out or is giving fits. Check the switch on the clutch pedal to see if secure or got knocked off. On my 93 had to change this switch and it was a pain in the >>>>>>>

 

where is the switch located?

 

under the dash, up near the pivot point for the clutch. in behind a brace on mine. If I remember right I checked the switch by unplugging it and put a jumper wire to act as a switch to see if it would roll over. When it did, I knew it was the switch.

 

Ok ill check that tomorrow. Im new with diesels. Ive only owned this truck for about 3 months. Do you think it has anything to do with the oil change because this has never happened before and this happened right after I changed the oil, before it was fine. Also, is it normal for the oil to have some air bubbles when you first check the oil?

Could it be the cam position sensor? It has been idleing a little funny at times. Everyone once in a while, while it idles, it starts struggling and goes to about 500 RPMs but never stalls. Im wondering if the cam position sensor has failed...

 

Sounds more like the clutch switch. I don't know about bubbles.... did you fill the new filter before putting it on? Don't know if that would cause the bubbles, but it seems that this is the more accepted practice for the oil changes on our trucks.

 

Yes, I filled the filter with oil. What does the clutch switch look like and what do I have to do to fix it? Also, why would that happen all of the sudden after an oil change or is it just a coincidence?

Thanks for all the responces so far!

 

Should be up on the clutch rod that goes through your firewall, should be 3(?) wires into the connection. Mine seemed to have gotten turned somehow awhile back, I attribute that to the nylon bushing that locks the clutch rod onto the pedal going south. Might want to check that too.

Probably just a coincidence... If it was due to the oil change, you would think that you would still be able to get it to turn over but not start.

Good luck.

 

Thanks for your help. Ill check up on that tomorrow. Any more advice is appreciated. Thanks!

 

Did you use CG-4 rated oil? The foam is making me suspicious. There are lots of oil blends on the market that are not compatable with the diesel engine. For instance: Castrol 20-50 GTX. A great oil for older gas engines. But it's not C-anything rated. You can't put it in a diesel engine, turbo or otherwise.

 

I used Shell Rotella T. The foam only happened when I first checked the oil after the oil change and when it did foam, there was very little of it. It doesnt foam anymore.

Im going to check the clutch safety switch later today when I get home. Is this something that needs to get replaced or just comes loose? What does it do exactly?

 

The switch could either go bad or get corroded from moisture from feet. Wiring snaps on so check this also. Hard to get off but it is possible (small %) to come off.

 

Had the same problem two weeks ago but on an automatic. Everything would light up but when turn to start from run-nothing! Check the small wire on top of the starter for power. You are going to have to have someone turn on the key(to the start position) and see if you are getting juice. If you are not getting juice try jumping the starter sylonide on top of the starter from the constant power to the starter. If it kicks on the starter you know it isn't the starter but either the ignition under the dash or the starter relay under the hood. What happened to mine was the starter relay under the hood went bad. Took me a while to figure out so I'm happy to share this info with everyone so that they might be able to trouble shoot the problem faster. Good luck and let us know what's going on.
tex1313

 

I looked at the clutch switch, the wires wernt loose and it didnt come unplugged either. How do I test it to see if its good?

I will test the starter later once I have another person here to turn the key. What does the ignition under the dash look like and which relay is the starter relay. Is the starter relay one of the 2 relays next to the power distribution box or is it inside of it.

 

take and unplug the wire from the switch be careful to not break the connector and run a wire from one connection on the plug to the other side of the plug.