140k too late to switch to synthetic?

my 328is has 140,000 miles on it and it has been given synthetic and conventional motor oil all its life (at least thats what i desearn from the service records i have) but im not sure when it last had synthetic oil. i know for the past 5 thousand miles it has has conventional oil for sure. i was thinking about switching to a synthetic oil to prolong my engine life. is 140k too late for the switch to full synthetic, would i be worrying too much about seals leaking i do want to go the synthetic way but i've heard bad things about swtiching to late in the life of a car...help me out

I have heard the same thing too. My car had a similar experience; back and forth between oils before I owned it. Mine had 85k and I went full synth. I would think that since yours has had some synthetic at times that leaking seals and the like would be less of an issue, if an issue at all. I say switch, sooner rather than later.

the only reason syn leaks is because it is thinner. It is actually not bad if it leaks this will atleast show you that you need to replace certain seals that if you didnt use syn you wouldnt have replaced. If it makes oil leak just replace the seal and your done no more leaks.

First I chage it with a "high mileage" conventional oil and run it 500 miles and change it again minus the filter but add one quart of synthetic blend. I then change it again at 1000 miles with two quarts of synthetic blend and the rest high mileage and so on. Once I get to full synthetic blend I change the filter and do a full synthetic blend change plus one quart of full synthetic and continue every 500 miles until you get to full synthetic..... I've been very successfull using this method and never caused a leak & I buy all my cars with over 100k. It's an expensive change over but worth it. I'm a believer in conditionioning the seals slowly and breaking the crud away slowly rather than abruptly. Other wise stay with a good "high mileage" oil like Valvoline, Quaker State or Castrol. My Cabrio has 142k and runs like a top. The oil does not even start to get dirty untill 3k and when I change it it's still clean. Even though I run synthetic I still change every 3k because it's cheap insurance...

I changed to synthetic at 180,000 miles and I haven't had a problem. It hadn't had synthetic before as far as i know.

If the engine oil/oil filter was changed on a regular basis, 2-3000 miles for example, then it should be OK.

It can be a problem though w/a vehicle which has had very little oil changes using mineral based oil, due to sludge buildup in the engine. Synthetic oil does a good job in keeping your engine clean, which is good, but w/the sludge, it can cause sudden problems, such as blocking oil passages and such.

If anything, running an engine flush through the engine might be a good idea first, if you really want to go the synthetic oil route.

I bought my 325is with 196,000 miles on the clock and it had conventional oil for most-likely it's whole life. What I did was I ran a blend of full-synthetic and Syntec blend for 6000 miles and then switched to full synthetic Mobil-1 and haven't had a problem since. I have about 206,000 miles now. It runs sooo much smoother throughout the rpm range with full synthetic in it.

-philip

Switched at 177,000 km with no problems. Currently at 213,000...

Hi, anyone have any experience using Redline Synthetic. I live in a hot humid salty climate, in Okinawa, Japan and would like to decrease engine heat.

Thanks, BD

redline is some of the very best oil you can buy, go for it.....and Btw everyone i just swtiched over to full synthetic 100 miles ago, i went from conventiional 10w30 to castrol syntec 10w40 and i think unlessi have big preoblems that this is what im gonna run from now on, ill keep you posted

Royal Purple