Oil leaks
This is not strictly feature Mustang related but I’m sure many of you can relate as our cars get older and/or usage of them decreases. There is a faithful reader of this site named Ron who sends me lots of good stuff via email and we have lots of good discussions over it. This is one of those topics we have discussed and a recent email from him on the topic prompted me to relay my experiences with oil leaks and rear main seals, in particular.
I have owned my car for five years and in that time I have had the rear main seal replaced three times. The first time was in the first month of ownership since it was leaking from day one and the remaining two times occurred over the five year period since. On one occasion the shop manager indicated the problem might be clogging of the metal mesh breather that sits underneath the PCV valve. If the pressure that needs to vent through there cannot due to the clog it has to vent somewhere and that somewhere is often through seals and gaskets. It was not in my case but Ron found that it was in his case (his leaked through the oil pan gasket) and I agree with him that many people might not be aware of it and, like me, have numerous service visits to try and fix the problem. I have seen this discussed in various places like stangnet and rec.autos.makers.ford.mustang but not too many others. Hopefully one more mention of this cannot hurt.
My own experience with my most recent leak is somewhat different. I noticed mine leaking again when I was putting my car away last winter (’06). I did nothing until spring. Barry, the guy who had his red feature car next to me at Carlisle and who has owned many fox-bodied Mustangs told me that he has had many rear main seal leaks and most occurred after/during storage and were cured as the car was returned to use. So, in the spring my approach was to…do nothing. Except, I switched away from the synthetic Mobil 1 I was using back to dino oil and I drove 600+ miles to/from Carlisle. Since then, I have had no leaks. Now, I am going to find some wood to knock on.
Two of the annoyances of the 302 engine are the rear main seal & waterpump leaking. The same rear main design was used from the 1960’s until the last 5.0 was produced (I think it was 97 or 98 in the Explorer). The rear main seal has a spring loaded rubber rim that rides against the crankshaft and as the seal wears or dries out it begins to leak. Fel-Pro does make an improved seal that costs around $40 (vs $10 for the stock replacement)
Same with the oil pan gasket– opt for the upgraded Fel-Pro blue colored silicone oil pan gasket– have never seen one of these leak like the OEM gaskets will tend to seep. The same blue gaskets are available for the valve covers — the stock gaskets made from cork typically are another easy fix to keep the garage floor clean.
Another reason to crank up the car in the winter & get a mustang fix while waiting for summer…….
Thanks, that’s some great information. If I remember correctly, when my rear main seal was done they used some “new” design of the seal. I hope it was the Fel-Pro.