I've heard of high miles car leaking when you switch to synthetic. Does the max do this? I wanna switch to synthetic on my next change.

 

if you already have leaks that arent visible at this time, then its more prone to leaking if you switch beacuse the flow characteristics are diffenet for synthetic

 

Yes it sure will make it leak the detergents in synthetic will get to those leaks and make them leak even more.

 

if you are not the first owner then you might want to look into the condition of the engine. Go to your car and look for signs at obvious spots where leaks normally occur. Or get a good engine flush that usually helps in determining leaks.
If all is well . . . . you can switch to synthetic.

 

When I heard a rattling noise from my max, I looked under and oil and antifreeze was all over the lower oil pan and dripping....after looking inside the lower oil pan, peices of the guide and tensioner were found(had to replace those anways 127k miles on it)....I think maybe the cause for the leak was the dealer swapping oil types...but im glad they did to confirm the need for guide/tens replacement....by removing the upper and lower oil pans and re-sealing them with silicone and new lip gaskets...will this fix the problem? *fingers crossed*

 

I've got a TINY leak out of my oil pressure sensor.....VERY minor, but probably due to synthetic

 

I think I'm the 3rd owner. The car has 147k miles, but is always at the correct oil level. I'm thinkin about switchin it and then switchin back if it leaks.

 

I was thinking of switching to synthetic too. The car has 153,000 km on it (Or 95,000 miles), is this too high?

 

I'm in the same boat. Actually just bought Mobil 1 and was about to switch. Have 101,000. No cuurent leaks. Should I do the switch or not???

 

i switched at 53k, its now 72k, no leaks no problems, knock on wood

 

If you have a high mileage Max, you might want to try on your next oil change going with 1 qt syn. and 3 qts regular oil. That way you will get some of the benefits of synthetic oil and check for leaks at the same time.
If you notice any leaks, just switch back to regular oil.
Just don't mix different kinds of synthetics together. Example, mixing Amsoil and Mobil one(BAD)!!! You can mix different weights of the same oil,5w-30 Castrol and 10W-30 Castrol. Also stay in grade when mixing your synthetics;example 5W-30 Mobil One and 5w-30 Castrol GTX.
Hopefully this will help out. Remember synthetic oils doesn't cause oil leaks. It's high detergents clean out all the gunk left over after all those miles.

 

I switched to Mobile1 @125K miles. No leaks prior to switch and no leaks now at 140K miles.

 

The most important factor is the condition and cleanliness of the engine before switching over. I've converted many high-mileage cars to synthetics with absolutely no problems...I've also refused to sell (synthetic) oil to people whose engines had been neglected and were in bad shape (because don't want them blaming the oil for their own negligence). As plummaxse points out, the most popular synthetics don't cause leaks...AMSOIL and Mobil use PAO basestocks for their synthetics...PAOs combined with the additive packages make them seal-friendly. However, synthetics have higher detergency than petroleum oils do and this will eventually clean away junk that has built up inside a neglected engine..as a result, the risk is that the synthetic will become dirty before its time, increasing oil consumption and potentially leaking from the previously damaged seals.

The bottom line is that you should be ok as long as there are no current leaks and the engine has been well maintained.

 

Beyond the leak question, ask yourself whether the increased cost of synthetic - for only a slight increase in wear protection - is worth it on a car of this age? I run it in both of my cars, and partly for the extended interval, but though syn is better, it's not that much better. Yes it's a far superior oil, but in practical application I just don't think it's tremendously important. There are still tons of new cars - expensive ones - that don't use synthetic from factory or with dealer refills.

 

I lots of stop and go traffic in my area, so the extra protection is definitely needed. I'll probably hit it with some sea foam before i drop the synthetic in.

 

also, should i use 10w-30 or 5w-30 for a hile mile max?

 

I switched at 75k, now have 127k, and lots of extras with no problems.