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The need for speed
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Discussion Starter · #1 ·
I had a FMS blow out on me at the road course which caused a car behind me to spin into the wall. I'd like to fix this problem so it doesn't happen again. From my research I've found 3 possible solutions to fixing the problem of having too much oil / crankcase pressure causing the FMS to blow out.

1) Order a replacement seal from Napa or carquest (not sure which place or what the part # is, but I was told the seal is a different design but still fits).
--Is there any feedback to this method if it has helped or not?

2) Order new oil pump with holes drilled through it to allow oil to pass through. Some people reem out the stock holes. SP offers this with a brand new seal secured in place w/ screws.
--I've read the larger holes reduce oil pressure which is bad for engine components.

3) Use a larger crankcase vent (on the exhaust side). Some people drill/tap the stock breather out for a larger AN-10 and run it to the intake or catch can. I've also seen others that are starting to re-route it to exhaust so it still provides suction but is safer against blowby.
-- Has anyone had a FMS go when they were using a proper size crankcase vent (a -8 or bigger line running from the vent to the intake?). I'm running a little k&n breather when my FMS went.

Thanks in advance,
Mike
 

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Mike91t just pulled his because it was weeping a very small amount of oil on his new motor with perfect compression. At first we were wondering about the possibility of the Lucus additive causing. That nutcase pulled it out and low and behold the stock one was defective!! There was an imperfection on the mating surface causing a poor seal. Solutions are the best catch can out there (-12) and the Napa seal. We'll see what happens...
 

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The need for speed
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Discussion Starter · #3 ·
Thanks for the info... I put another stock seal back in because I needed to get the car running asap. Do you know what the NAPA seal part # is? I can't seem to find it on mkiv.com or SF.
 

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there are a few different ones we are contemplating. The one I think I'm going to try is a tranny output shaft seal. It is like 1mm tighter in every aspect of the seal. I'll get him to put up the numbers.
 

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GA Rocks!
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vent your dipstick into a catch can. i went through 3 fms before i found that out. My car revs up to 7800 and 28 psi without any FMS problems anymore. The stiffer seals work but they don't last long. The stiffer you make the seal, the more likely hood seal will wear out early. I've tried everything from double springs, napa seals, changed the oil pump, etc. Only one fix has lasted 2 years.
 

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sidwin said:
vent your dipstick into a catch can. i went through 3 fms before i found that out. My car revs up to 7800 and 28 psi without any FMS problems anymore. The stiffer seals work but they don't last long. The stiffer you make the seal, the more likely hood seal will wear out early. I've tried everything from double springs, napa seals, changed the oil pump, etc. Only one fix has lasted 2 years.
do u also have your crankcase to a catch can?
 

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The need for speed
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Discussion Starter · #7 ·
sidwin said:
vent your dipstick into a catch can. i went through 3 fms before i found that out. My car revs up to 7800 and 28 psi without any FMS problems anymore. The stiffer seals work but they don't last long. The stiffer you make the seal, the more likely hood seal will wear out early. I've tried everything from double springs, napa seals, changed the oil pump, etc. Only one fix has lasted 2 years.
Excellent - that's an idea I haven't heard before. So you're saying just remove the oil dipstick and attach a hose to it going to a catch can?
 

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sidwin said:
vent your dipstick into a catch can. i went through 3 fms before i found that out. My car revs up to 7800 and 28 psi without any FMS problems anymore. The stiffer seals work but they don't last long. The stiffer you make the seal, the more likely hood seal will wear out early. I've tried everything from double springs, napa seals, changed the oil pump, etc. Only one fix has lasted 2 years.
You have the dipstick removed, correct? How would you suggest checking oil level with this setup? Or do you just go by pressure and never check your levels?

Thanks,

Johnathan
 

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0wned said:
You have the dipstick removed, correct? How would you suggest checking oil level with this setup? Or do you just go by pressure and never check your levels?

Thanks,

Johnathan
hopefully once the fms is fixed we wont have to worry about the oil situtation even though i always do check my oil before driving.
 

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GA Rocks!
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i put the dipstick in when i want to check the oil. I have a barb fitting that goes -6an on one side ad to a silicone hose on the side. That way I can just slip the hose over the dipstick and not have to use any clamps there. I believe it is the same diameter as the hose i used on the PCV valves on the cam covers.

yes my car blew the fms even when i had the valve cover catch can. Then i tried to route valve cover catch can into the turbo air intake to reduce the pressue and yes it blew when i had that done as well.

Thanks,
sid
 

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interesting theory about the dipstick. I've always been told that before your fms would blow due to crankcase pressure your dipstick would push out. ie: dipstick is easier to push out than fms.

But if it works wth :) some things don't make sense.

I've found that as brenden has mentioned earlier my fms weeping was caused by an oem seal that was defected. I have all major aftermarket seals on the way to test and compare specs. I will update soon on the findings..
 

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if crank case pressure was so high why aren't the cam seals being pushed out?

the problem is if you vent the dipstick, u need to check your oil level frequently. you will be surprised how much oil/fuel comes out of there. People think it is only droplets because that is all you see on the ground when you aren't catching the fluid. I've read dsm blowing their dipstick completely out. I don't think ours would do that but i do believe we need to find away to alleviate that extra pressure.
 

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The need for speed
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Discussion Starter · #13 ·
sidwin said:
if crank case pressure was so high why aren't the cam seals being pushed out?

the problem is if you vent the dipstick, u need to check your oil level frequently. you will be surprised how much oil/fuel comes out of there. People think it is only droplets because that is all you see on the ground when you aren't catching the fluid. I've read dsm blowing their dipstick completely out. I don't think ours would do that but i do believe we need to find away to alleviate that extra pressure.

Have you / would you consider modifying the oil pump (drilling holes through it like what others have done)?
 

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GA Rocks!
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i put a brand new stock oil pump in. a major pita. i've read others who did drill and have their seal pop out..... i don't think that is the final fix..
 

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Lucas oil additive will not cause it to blow, in fact after using the additive, if you ever pull apart motor and look at rod bearings that have been abused over and over...you will never stop using that stuff, they look like new. The Napa seal does not work any better. 99% of time its just the seal when put, banged, whatever in....does not go in straight or has a small kink, or is uneven. Or if you go to far in , you block the small drainage hole. Stock seal put in straight with a nice breather tank that is more then a empty can will solve all problems Mike. And fwiw a weeping front main is pretty much normal no matter what at somepoint, even with everything else perfect. And lots of failures are due to not getting a new oil pump when they have motors out. Just put a new stock one in and call it a day. If they work best for me....will surely work fo you PA guys who have never seen over 15 psi :1poke: But seriously though, you guys will never push your cars as hard as me and i have no problems with stock seal and good breather tank/ catch can.
 

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Will these tips also apply to rear main? I recently did mine shortly after my FMS (RMS went out) and don't want to repeat it. FMS is ok, but RMS is pita.
 

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Bren was bitching about the lucas tony. I run it in my truck and my car and I have seen 800,000mi engines that have run lucas and showed almost zero wear. My seal leaked slightly more than the normal weeping. I set my base boost now to 15.3 psi and it hadn't leaked any worse. I removed it since I was changing some things in the front anyway and found it had a defect (I can show you sometime what it was). I know the most common mistake is an incorrect install by not installing it square so I used a seal driver when it was installed and it was perfectly squared with the pump. Also the driver allowed me to keep it from being pushed in too far which can block the drain hole and cause a hydraulic effect from the pump to push the seal out.

One of these days tony I'm gonna take you a ride and show you my school bus driving techniques in the supra :)
 

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Does it matter where you vent the crank breather (I forgot the exact name) on the intake side? I run a line to a catch can from the exhaust side, but my intake side still goes to the intake manifold. Is that bad?

I mean, the intake manifold is pressurized by the turbo, so doesn't that pressurize the crank case too? Possibly causing the seal to blow out? And increasing your spool time?

My seal was replaced and within 20 miles I lost 4 quarts of oil, then it was replaced again with a different brand and after 50 miles I'm out of half my oil again. Very, very annoying. I don't want to have to get this fixed every 100 miles.
 

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anyone ever thought about crankwalk contributing to fms seals blowing out? cause i have pulled my harmonic balancer 3 times, and every time my fms is about halfway out, so i pop it back in with a proper tool, and it has popped out again after, and i'm 90% i have the beginnings of crank walk. crankshaft moves forward on acceleration and pushes the seal out.
 
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