Leaking seals on 99 OBW

[Shep2112]

Hey all, just wondering, I had my engine rebuilt about 3 years ago (50k miles back) and everything was fine. I was running synthetic in it before and after the rebuild. I had the oil changed earlier this year and my trusted mechanic told me there was no problem switching from synthetic back to dino oil. Then about 8 or 9 months later, I was having some work done under the car, and another mechanic noticed the seals were leaking a bit.. I don't know how many, or which ones, but I looked and I could see that in a number of places, there was a bit of oil/seal squeezing out. He said something about the particle size between the oils being different, and switching to dino oil from synthetic would cause this problem.

 

Is this true? I don't remember if the seals looked like this at my other mechanic earlier this year. I don't know if I should be concerned about this or not. Or if switching back to synthetic will have any effect.

 

The original mechanic who made the recommendation to switch back to dino is part of a father/son racing team and they have always steared me right before, so I don't know what to think.

 

Any thoughts?

 

Thanks!

-Eric

[porcupine73]

It is possible for what you describe to happen but not necessarily likely. What brand synthetic were you running? Some synthetics have a fair amount of seal swell agents to prevent seal shrinkage and subsequent leakage; or some high ester content synthetics can cause seal swell and then possibly when you switch back to dino the seals could shrink back a little thus allowing leakage. If this happens I'm not sure how long it would take and I have not heard of it happening much especially not with newer oils.

 

However, what 'seals' are leaking? RMS? front crank/cam seals? Were these replaced with OE parts during the rebuild?

[idosubaru]

what do you mean by "rebuilt"? what all was replaced and why? the entire block, pistons, rings, bearings were all torn down or just a head gasket job? were all seals replaced? aftermarket or Subaru seals used?

 

do a search on "switching" from dino to synthetic or the other way around on this forum or the internet. you will find oppinions on both sides. pick one and stick with it, it's not like one will make your engine last to 250,000 miles and the other will not.

 

why did you switch in the first place?

[Shep2112]

Thanks for the replies.

 

The synthetic I was using, I BELIEVE was Mobil 1. I know I was running that for a few years. I may have once used Pennzoil or Castrol, I don't remember now, but usually it was Mobil 1.

 

The rebuild job was a major undertaking, I don't recall all the details (it was 3 or 4 years ago). There was a microscopic crack somewhere in the block (according to an inspector hired by Subaru and the dealership that did the job). They said it was most likely a manufacturing defect. They used some of my original parts, and some new stuff. It was more than the head gasket. I think they had to re-bore the cylinders and stuff, to get it all back within spec. The dealer originally said they were hoping to just get me a new engine to drop in, that it would be quicker, but that it was up to Subaru. Then Subaru told them no engines were available as quickly as doing a rebuild. (This was covered under the Gold warranty, around 74k miles).

 

I was driving from Massachusetts to Florida when a thermostat stuck (just after having the car idling). I looked down and saw the temp gauge up, tried to blow the heat off with the HVAC controls but it didn't work, so I called AAA. Long story, ended up taking about a week to get the parts and do the job. Subaru covered $500 of personal expenses (hotels, meals, rental vehicle, etc).. It ended up being cheaper to drive from North Carolina to Florida and then driving back 4 days later, than staying there in a hotel. Subaru was really good to me, but I wish I had a new engine dropped in and was on my way. The dealer said that would be about a $4,000 job and didn't know if Subaru would be interested in that.

 

I went to synthetic in the first place because I was led to believe it was better to go with that. I think the switch back to dino last week happened because I requested an oil change and some other work with my mechanic, and by the time I remembered to point out synthetic to them (I called a couple hours later), they were already done with the change and said it wouldn't cause any problems, synthetic was overrated, etc.

 

I don't know which seals they are. When I saw the leaks a few weeks ago, the car was on the lift. It was in several spots, along the passenger side, underneath, in front. The mechanic gave me the impression it was anywhere that oil runs behind was leaking slightly. He said it shouldn't be much of a problem, but eventually the seals would break down too much, etc.

 

Hopefully this is enough info for you guys.

[idosubaru]

thanks for the details. i don't think you have anything to worry about. if you do, we don't know enough to instruct you. the best thing you can do now is to make sure the oil level is full. check the oil level everything 1,000 miles and see how much you are loosing and let us know. my guess is you're loosing very little. some minor seapage is no big deal and quite common on engines with some years and miles on them. most likely you're only seeping very small amounts and that's what you're seeing. small drops blow all over the bottom of the engine while driving and make large areas look wet, but don't signify serious issues.

 

keep in mind that you can take care of these oil leaks most likely at your next timing belt change. the cam, crank, oil pump seals all reside behind the timing belt and only cost a few dollars. so these can probably be cured at your next timing belt or water pump change for a few extra dollars (the seals run $25 or less). there are also valve cover gaskets that could be replaced as well.

 

to determine exactly where the leaks are, post a picture for us and/or clean the bottom of the engine off real well and check it again later to tell where the spots are coming from. at this point it's probably too wet, blown around and spread out to tell exactly. there's more info on this forum (i think i've posted it 10 times) about how to track down a leak and what they mean...search for those threads if you're interested in doing that.

[Shep2112]

Thanks for the advice. I remember I got the timing belt done around 58k or so, because it was in the shop anyway. Is the timing belt every 60k?

 

Is the timing belt and the seals something I could do myself with the right tools? My wife is an aviation maintence technician and has about $6k in tools and works on 4 cylinder horizontally opposed engines on a daily basis. Granted, they're aviation engines, 2 plugs per cylinder, but she has all the tools n stuff. It seems to me the timing belt was fairly deep inside, but if it'll save me some money and not be a really complicated job, that would be cool with me.

[unibrook]

Your wife can probably do the timing belt in her sleep.

[Shep2112]

Hahaha, yeah and changing the plugs on a Lycoming engine is a hell of a lot easier than in a Subaru!

 

Are there instructions anywhere online for changing the timing belt and the seals?

 

Thanks!

 

Your wife can probably do the timing belt in her sleep.

[rweddy]

He said something about the particle size between the oils being different, and switching to dino oil from synthetic would cause this problem.

 

Is this true? I don't remember if the seals looked like this at my other mechanic earlier this year. I don't know if I should be concerned about this or not. Or if switching back to synthetic will have any effect.

 

The original mechanic who made the recommendation to switch back to dino is part of a father/son racing team and they have always steared me right before, so I don't know what to think.

 

Any thoughts?

 

Thanks!

-Eric

 

Synthetic oil causing oil leaks is a commonly spread myth.

The truth of the matter is that if all your engine seals and gaskets are in good condition, synthetic oil will NOT leak in your engine. The myth started because on occasion, an engine will leak with synthetic oil, but not dino oil. The reason for this is that the smaller molecules of the synthetic are able to get past very small crevices, where the larger molecules of dino oil cannot. But this does not mean that the synthetic oil has caused the leak, it simply has "discovered" an infant leak, and regardless of what oil you are running, this infant leak will eventually grow to a size that will allow dino oil to occupy and pass also. Synthetic oil has not been shown to deteriorate engine seals or gaskets. It is not some evil solvent that will break down sealant, or anything like that.

[nipper]

its not a myth, your just not inderstanding it. Going from Dyno to synthetic may make the gaskets leak for a very short period of time, but it usually goes away. Seals on the other hand, it just means that they are going to leak sooner, but were going to anyway. Synthetic oil has a smaller molcule and will find place to travel, but as dirt get in these places, the leak will stop.

On the other hand, switching from synthetic to dino oil may cause leaks.

Now if you switch to or from synthetic and the car leaks, it means it was going to leak eventually anyway. Switching back its not uncomon to have leaks, but then again it just means you were going to have them anyway.

 

Now the question is do you want to leak 1.50 a qt oil or 5.00 a qt oil.

 

 

nipper

[Shep2112]

It wasn't a large amount of oil, and every time I've had it changed, it's always been within the fill tolerances. Did he say gaskets and not seals? I can't remember now.

 

But I do know it was on the right side, bottom, and near the front, looking up from underneath. I'll try to find a manual car wash that sprays hot water and put some degreaser on the engine and spray it off and then look after a while for leaks.

 

So then syn oil would have smaller particles and come out easier than dino oil? Then why would switching back to dino oil and its larger particles be a 'reason' for the seals to leak? I understand what you're saying about the fact that it was going to leak eventually and all that. Just not sure how these things get started. It seems like if I went back to larger particles, the problem would correct itself, no?

[nipper]

It wasn't a large amount of oil, and every time I've had it changed, it's always been within the fill tolerances. Did he say gaskets and not seals? I can't remember now.

 

But I do know it was on the right side, bottom, and near the front, looking up from underneath. I'll try to find a manual car wash that sprays hot water and put some degreaser on the engine and spray it off and then look after a while for leaks.

 

So then syn oil would have smaller particles and come out easier than dino oil? Then why would switching back to dino oil and its larger particles be a 'reason' for the seals to leak? I understand what you're saying about the fact that it was going to leak eventually and all that. Just not sure how these things get started. It seems like if I went back to larger particles, the problem would correct itself, no?

 

 

excpet every time you change from one type to the other, the change takes the dirt with it, hence the short term leaks if its from a gasket.

 

nipper

[Shep2112]

So you mean the dirt is sealing the small leaks and when the oil is changed, the dirt sealant is removed?

 

I wouldn't think it would be leaking with less than 50k since the rebuild. As far as I know, they redid all the seals and gaskets because it was completely torn apart for inspection.

 

Oh the horror of seeing my poor engine spread out over 3 workbenches and a cart and some other things.. Somehow they got it all back together though.

 

excpet every time you change from one to the other, the change takes the dirt with it, hence the short term leaks if its from a gasket.

 

nipper

[idosubaru]

shouldn't leak after 50,000 miles but like i said sounds like it's a very minor leak. maybe just one seal wasn't seated perfectly? at the 100,000 timing belt change you can have the leaky seal replaced for less than $10, if it's coming from behind the timing belt covers up front, then it sounds like it's one of those seals. or have a look and make sure it's not valve cover related. engine degreasers suck by the way. i can't recall what it is, but there's an excellent product that washes away grim off the engine.

[nipper]

shouldn't leak after 50,000 miles but like i said sounds like it's a very minor leak. maybe just one seal wasn't seated perfectly? at the 100,000 timing belt change you can have the leaky seal replaced for less than $10, if it's coming from behind the timing belt covers up front, then it sounds like it's one of those seals. or have a look and make sure it's not valve cover related. engine degreasers suck by the way. i can't recall what it is, but there's an excellent product that washes away grim off the engine.

 

Soap?

 

hehehehehe

 

nipper

[Shep2112]

Yeah, I had good luck with just a high powered wand set for soap at a manual carwash several times. Have to find one of those around here. I'll give that a shot this week.

 

So then the verdict is, don't switch back to synthetic I guess? Or was it why bother using it in the first place?

[mjreilly]

i can't recall what it is, but there's an excellent product that washes away grim off the engine.

 

Wasn't Simple Green marketing originally as a degreaser?

 

matt

[nipper]

Yeah, I had good luck with just a high powered wand set for soap at a manual carwash several times. Have to find one of those around here. I'll give that a shot this week.

 

So then the verdict is, don't switch back to synthetic I guess? Or was it why bother using it in the first place?

 

In all honesty i really dont see the advntage to synthetic. People forget that synthetis oil still has a filter that needs to be changed at mfg required intervals. If you do the math over the lifetime of the car, dino oil is cheaper then over the lifetime of the car, and its been doing well for almost a 100 years.

We can sit here and do the discussions and arguments all you want. Unless you have extreem driving conditions or weather, stick with whatever you feel comfortable with. if you dont do your own oil changes, its hard to find someone to just change a filter.

 

nipper

[Shep2112]

Nipper: Yeah I would usually go about 5,000 miles with the Mobil 1 and then change it. I remember reading a while back that synthetic was supposed to be good for 10,000 miles, but you had to change the filter at 3-5,000 still. But then Mobil 1 came out with a 10,000 mile oil earlier this year, so maybe it didn't REALLY go to 10,000 before?

 

MJReilly:

I believe so. Whereabouts in western mass are you from? I'm from Dalton, but I'm in Orlando currently.

 

-Eric

[nipper]

Wasn't Simple Green marketing originally as a degreaser?

 

matt

 

It does a really really good job on degreasing, but it can be harsh on some plastics (like the clear plastic over the gauges)

 

nipper

[Shep2112]

oh, thanks for the heads-up on that.