Fellas I got a problem. I am losing oil. This is an intermittent problem and I can't figure it out. I have a 97 F250 w/ 460 Manual. One day 4 or so months ago I started my truck in the morning and noticed a ticking sound. Oil pressure was normal. After further inspection I was about 2 quarts low and I noticed that there was some oil on the oil pan. So I changed the oil and drain plug gasket and it seemed to fix the problem until last week the same thing happened again. I use Mobil 1 full synthetic and I replaced the drain plug with a magnetic one from napa long ago. Every time I change my oil (every 4000 miles) I use a new plastic crush gasket but I have also tried the copper ones. This last time I used some Blue "oil resistant" RTV for a gasket. I don't think that I am burning oil because there is no smoke ever and I have never seen an oil puddle under my truck. So, is the oil leaking when the engine is hot while I am moving so I never notice the leak? Is the RTV the way to go to fix the problem? Any advice would be great.

Kevin

 

You don't say what your oil usage is per miles driven, so it's a little hard to make some recomendations. However, if you are using a quart every 500 miles, for instance, and it was only coming out when you were driving I can tell you the underside of your truck would show it. Also when you parked it you would be getting drips and puddles on the ground. Since you say there isn't much on the ground, my guess is you're burning it.

Now, that this has happened to you twice, I would say start checking it regularly and see what the trend is. Did you change your driving style? For instance, did you do some towing or something before these episodes?

Regarding your question about the RTV silicone, if it's not leaking then stick with it (no pun intended.) There is evidence that suggests that the regular RTV is eroded by synthetics but I think that is a more important consideration when changing fluids that have extended drain cycles, such as gearboxes and differentials, or on gaskets, but not on a drain plug that's getting a periodic fresh coating.

BTW, I don't want to start a major debate but the synthetic might have something to do with your problem. There are a lot of guys on this forum that can address the pros and cons of that more intelligently than myself, though.

 

Thanks for your reply.

I check the oil regularly (about every other fueling) and have never noticed a study decline in the level so im not sure that I could determine oil usage per miles. But I will keep a closer eye on it.

Do you mean that the synthetic oil is causing the leaks or contributes to the engine burning oil?

As to my driving style, I havent changed (according to my wife LOL) I tow a small 5th whell on weekends in the summer and haul loads in the bed ocasionally for work but nothing major.

If I was burning oil would the spark plugs tell the tale? and if so would it be all of them or could it be just one or 2 cylinders?

Thanks again,
Kevin

 

Synthetic is well known to find leaks and make existing leaks worse. It's probably spread down the highway. Take a look at the bottom of the bellhousing, I bet you'll see oil there.

I'd try something like Valvoline Maxlife. There have been some people on here who have had great results with it.

Concerning the drain plug, how tight do you get it? I've never had to buy a new drain plug, or gasket, for any of my vehicles. Of course, I usually tighten mine to about 35-40 ft-lbs.

 

Good point on all the plugs or 1 or 2. Depending on the consumption you might see some evidence on 1 or more plugs. However, my V10 burns in the vicinity of a quart per 1,000 miles but when I changed the plugs they were textbook clean burn. My personal experience is that you have to really be burning some oil to see it on the plugs, especially with the strong spark of electronic ignitions. As a matter of fact I used to dump my stale premixed 2 cycle gas in my '84 F150 with a 300 and it never even flinched.

I should have mentioned in my earlier post that if it was LEAKING a quart per 500 miles the underside would be coated.

Regarding the synthetic, I was hesitant to even throw that out because that is an area that I'm not really into. Hopefully, TallPaul or Flash, who are two guys that come to mind as being more conversant with the oil properties, will come along and read this and weigh in. There are a lot of other posters that can skillfully address that also.

If you can put a number to your oil consumption it would be more helpful. With my V10 I've decided to put the oil in between changes as long as it doesn't get worse. Posts on the V10 board a while back suggested that 1,000/quart wasn't uncommon. So, if you track yours and it's stable, you might decide like I did that it's in the personally acceptable range. This isn't meant to talk you out of troubleshooting it it's meant more as a philosphy to consider if you've exhausted all possibilities.

Finally, I assume that you've had the truck long enough to feel that this is an unusual usage.

I hope this reply was of some help to you.

 

I bought the truck new in 97 and started using Mobil 1 at 1000 miles. I have never used anything else. When it first happened I thought it was just a one time thing which was bolstered by it not happening for the next four months. However with it occuring twice I get the feeling that it may happen again. The truck now has 78,000 miles on it. It may be time to switch to dino oil. I used the Mobil 1 simply because it flows well in cold weather. When my friend the ford mech told me that the engine looked new in the inside at the 30k maintenance I figured I would stick with it to spite the cost! To answer your question this is unusual.

As to the plug, I replaced the stock plug with a magnetic tipped plug for the purpose of snagging any would be engine damaging metal particles in the oil. I know that this is a job for the oil filter but a little extra never hurts right. I never used a torque wrench when replacing the plug so I couldn't accurately say how tight it was. Damn tight is as close as I could tell you.

With respect to the gasket I thought they nedded to be replaced at every change.

Thank you both for your input.
Kevin

 

Technically you should replace the gasket at every change, but I never have and never had a problem.

D*** tight should be good, and I'd be surprised if that's where its leaking. The magnetic oil plug is always a good idea. You're on the right track, and I'd suggest the Valvoline Maxlife. If you're burning it through the rings, there's nothing you can do short of new rings.

 

Thanks again for the infor fellas. Ill keep you posted on the outcome.

Kevin

 

Just a couple thoughts (hopefully no duplication with the info above). Seems something must have changed with the engine since you have used the same oil all along (or did Mobil change their oil formulation?). If you don't have significant leakage to account for the loss then volatility of the oil could be an issue. Did Mobile change it with a resultant lower flash point? Is the engine running hotter due to a clogged cooling system or some other factor? Valvoline Maxlife has a listed flashpoint of 230C for 10w30 and 242C for 10w40, both excellent. So I like the Maxlife idea as it would help rule out volatility if consumption goes down with it. Might be worth a look at the Mobil 1 tech data info on their website to see what they list the flash point as. Also, from what I have heard Mobil 1 is thin within the viscosity grade, whereas Maxlife is a bit thicker.

 

Tall, If you can believe the factory engine temp guage the temp has remained normal. Mobil lists the flashpoint at 224 I think for the full syn. If I had to guess I would say it is probably thinner than most.

Thanks,
Kevin

 

Flash point of 224 C indicates you are using 5w30 Mobil 1. The other Mobil 1's give better flash points, but if you want to stay with a 5w30 I would say, try Valvoline Synpower 5w30. It has a flash point of 242C and its pour point is -42 (Mobil 1 5w30 pour point is -45, close enough). Valvoline Durablend's flash point is 238 C and pour of -39. While I really like Maxlife, its 5w30 seems weak with a flash point of only 221C. Frankly, it looks like the Valvoline Durablend is nearly as good as the Synpower and you could save a buck or two per bottle. I know from personal use that the 5w30 Durablend is pretty good stuff.

 

Tall, Yes it's 5w30. I run 5w30 in the winter and 10w30 in the summer. By the way, I see you hail from the D. I grew up in Chelsea.

Kevin

 

I used to hike a lot on state land by Chelsea. Nice town, though it is getting to be a big upscale suburb these days. Spillover from Ann Arbor I guess.

 

I haven't been there since I was 16 but I hear that it is huge. When I lived there it was a very small town. Some of the best fishing I can remember. Overall a great place to live. Ahh, to be young again.