SouthrnmudslngR

I have a 2000 with the 5.4. Well I noticed about 9 months ago I was losing oil. My friend was changing the plugs for me one day and pulls one of em' out and it was covered in oil. So I took it to the shop and they said it was a valve cover gasket. So they fix it and a month or so later I notice it is still losing oil, I took it back and they said the couldn't figure out the problem. It's not leaking because there is never oil on the concrete below my truck. I don't guess it's burning because I haven't ever seen smoke fromm the exhaust (although its a cutoff/turndown pipe). I have no idea? Also a couple other questions. I was told not to flush the tranny since I haven't done it since 90,000 miles (now has 160k) and this kinda worries me. And the rear end, I've never had the fluid changed out in it, should I worry about it now?

Just call me Sean

iTrader: (1)

I don't see why you wouldn't want to flush out the tranny, the more crap and particles you get out the better. Same with the rear, new fluid is better than old fluid, and it gets out any metal particles that may be in there. As far as the oil, it's leaking or burning, it has to go somewhere.

lasttruck

Fresh fluid can wash away any build up on the gaskets allowing them to start leaking.

Is the plug still getting covered with oil? If it is the external part of the plug a rocker cover gasket change should have helped (assuming it was done correctly). Internally the plug could be burning the oil off without visable signs if it is a very small amount at a time.

What does the manual say about your year truck for the rear axle. If filled with synthetic, you may not have to change the fluid unless you have been in deep water or mud and contaminated the fluid.

Just call me Sean

iTrader: (1)

When you change the filter you put a new gasket on anyway, so what's the big deal?

SouthrnmudslngR

as far as flushing the tranny i was told that doing it now could cause it to slip. I was told this by an ase master certified mechanic who's been doing it for 20 some years and used to be my next door neighbor. And i dont know if there is still oil on the plug or not cuz I haven't pulled it out.

NGM

Check for oil on the plug.. Check the plugs for a gross buildup on the electrode side of the plug as this is a sure sign of the truck using oil. Flush the transmission. If it slips it was going to go out soon any way. Flushing will not cause it to leak. I don't care if its synthetic oil in the rear diff or not it needs to be serviced periodically. 25,000 for regular gear oil and 50,000 for synthetic.

hhntr111

I agree...fresh fluid is never a bad idea. Fresh fluid doesn't cause slipping anyway, as far as I know. I get the front and rear diffs done every couple of years, and the tranny about every 40k miles or so.

129k and runs like a champ.

NGM

On old transmission fresh fluid would hurt the interior seals and cause the fluid to bypass and the clutches would burn up. Square seal transmissions dont have that problem near as much.

skidmarks

the oil leak could possibly be an oil sending unit, mine broke . i run royal purple and use a little oil because it makes it to the combustion chamber easier? but the head gaskets leak also. add more oil does that make oil changes longer? ha ha

simpsonvillebill

That doesnt make any sense at all. Have you brought it to ford? And if thats who you brought it to what do they think it could be. Also are you running regular or synthetic? Or did you change over from one to the other?