A friend of mine picked up a '94 GMC Suburban with the TBI 350. Weeps a little bit from the rear main seal. I suggested he try Valvoline Maxlife to see if that helps slow it down at all - also couldn't hurt with 184k miles on the engine. After reading some threads here, and on other sites, many people are commenting that Maxlife doesn't work as well as it used to. Of course, no real data to back that up, but it does appear that Valvoline changed it's formula to meet Dexos Gen 2 specs. Is there a "better" high mileage oil out there than Maxlife these days for rear main leaks? I have run FS Maxlife in my '98 Chevy, but it hasn't been a leaker to speak of.
Other high mileage options that are easily attainable at WalMart:
Mobil 1 High Mileage
Pennzoil High Mileage
Castrol GTX High Mileage
SuperTech High Mileage
Any experience or anecdotal evidence that any of these work better the another for seal leaks?
Maxlife - still the best oil for R/M seal leaks?
- Thread starter RonRonnster
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Originally Posted By: RonRonnster
A friend of mine picked up a '94 GMC Suburban with the TBI 350. Weeps a little bit from the rear main seal. I suggested he try Valvoline Maxlife to see if that helps slow it down at all - also couldn't hurt with 184k miles on the engine. After reading some threads here, and on other sites, many people are commenting that Maxlife doesn't work as well as it used to. Of course, no real data to back that up, but it does appear that Valvoline changed it's formula to meet Dexos Gen 2 specs. Is there a "better" high mileage oil out there than Maxlife these days for rear main leaks? I have run FS Maxlife in my '98 Chevy, but it hasn't been a leaker to speak of.
Other high mileage options that are easily attainable at WalMart:
Mobil 1 High Mileage
Pennzoil High Mileage
Castrol GTX High Mileage
SuperTech High Mileage
Any experience or anecdotal evidence that any of these work better the another for seal leaks?
I've never had a rear main seal leak, so I cannot comment on any oils totally effectiveness at stopping that sort of leak.
Many here are very happy with maxlife. I'd say he try that first and see what happens.
I had some leaks on my 97 civic and 98 Sienna. I used liqui moly motor oil saver and had good results.
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I was a skeptic on HM oils until I put PZHM in a leaky Ford Windstar V6. A miracle drug. Completely dried up a soaked motor. If I needed it, I'd use it again for sure. Can't comment on MaxLife.
I do not endorse these products..just have seen the bottles.
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I can honestly say Maxlife dried up a leak very well in my Jeep, since using QS HM it is a leaker again. Not a huge amount but that is one data point. Good luck with your friend's leak.
Valvoline MaxLife does not swell the seals, an important distinction. We know it doesn't swell the seals much because it passes seal-swell tests in SN, and dexos1 for the full syn Maxlife. Maxlife conditions the seals. Conditioning may stop a <span style="font-style: italic">small</span> leak, as the seals would get more flexible, yet for something old already leaking, I'd definitely put in something like krismoriah72's Bar's or Blue Devil. See above post.
Every 'fix in a bottle' I've tried worked initially and then stopped working some time later.
Even AutoRX was able to temporarily stop a leaking RMS, but the leak returned on the next oil change.
ATP 205 slowed the leak, but didn't stop it.
High mileage oil temporarily stoped the leak, but it returned later.
I'd leave it or pony up the money or sweat equity to replace the entire seal.
Originally Posted By: krismoriah72
I do endorse these products..just have seen the bottles.
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Maxlife worked to stop the RMS leak my Jeep had. Smitty's Super-S Completely stopped the leaks and oil burning the wife's Tahoe had.
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Dripping or wicking (engine famous for later) … Mobil 1 10w30 High Mileage is a tad thicker with having to go 40’s …
Originally Posted By: SHOPete
I was a skeptic on HM oils until I put PZ HM in a leaky Ford Windstar V6. A miracle drug. Completely dried up a soaked motor. If I needed it, I'd use it again for sure. Can't comment on MaxLife.
Maxlife red bottle would be my first choice although M1 HM seems to work as well. The main rap I have on Maxlife is that the newer formulations no longer have any moly content.
The Maxlife is cheaper OTS but the M1 will be cheaper AMIR if you wait a couple of months for one of their MIRs.
Maxlife Red bottle and probably the 5w30 variant. Don't bother with M1 for this problem.
I've tried most brands of HM oils because my RMS drips on my clutch and causes chatter for the first few starts if my commuter car sits for more than 2 or 3 days.
MaxLife is hands down the best at stopping this from happening.
I got a case of NAPA HM on sale a while back and it seems to work almost as well as the MaxLife. Maybe this is because NAPA oil says it's made by Valvoline?
Tried Mobil 1 HM 10w-40 in the Jeep when it started leaking from the RMS. It actually leaked more. The 4.0 has had mostly QS 10w-30 syn it's whole life. Put in GC 0w-30 with a can of Liquimoly Oil Saver and the leak has almost stopped completely.
Valvoline tends to be the gold standard when it comes to high mileage oils. It would be my first choice but if you have a favorite brand other than Valvoline, you can go that direction too.
The comment about NAPA oil is correct. If that is cheaper for you then use it with no worries.
Liquimoly motor Oil Saver is a very good product. I have used it with Maxlife and it slowed or stopped just about every oil leak/seepage... If it still leaks after a 5K OCI with the above, then I would repair whatever is causing the leak...
This is what I have found to work the best on a RMS leak;
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