Wondering whether oil stop-leak products are worthwhile. I am thinking of using a seal rejuvenating oil additive that is supposed to fix rear main seal leaks. I was told my rear main seal is leaking and that it would cost about $350 to have it fixed. I've been adding oil--seems to make more sense to add a quart every three weeks or so than to spend that much on a repair for a 16 year old car. Suggestions?

I have had very good succees on volvo oil leaks by just cleaning the crankcase breather system. This system needs to be clean to work, any plugging and you will see leaks. If the breather on the block is really dirty- you can buy a new one for about $35. I would not try any additives. Read the FAQ on this breather system.

Mike in Tacoma
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Current: '89 780 Turbo, 1986 245, 1986 740 Turbo RIP: 1983 245 Turbo, 1984 245 Turbo

The stuff in the parts stores won't really help, but a couple of treatments of Auto Rx ( www.auto-rx.com ) may just take care of it for you. I've taken care of countless seal leaks on mine and customer cars with that stuff and it's a long term soloution when it works. At the very least, you'll have a nice clean engine inside.

Make sure to clean the flame trap and check the oil seperator for obstruction before anything, see the faqs
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-------Robert, '93 940t, '90 240 wagon, '84 240 diesel (she's sick) , '80 245 diesel, '86 740 GLE turbo diesel, '92 Ford F350 diesel dually

I debated not doing this job (changing the rear main seal) for a while on my 1992 940, but I got sick of the ugly oil spots I was leaving in the street in front of our house. I'm doing this on my own using a $60 tranny jack from Harbor Freight.

Click here to read the information in the FAQ's about crankcase ventilation. The first step to stopping oil leaks past seals is to be sure the crankcase is not pressurizing during operation.

The FAQ's are reached via the drop down menu in the very upper right corner of this page.

Additives have little effect on oil leaks... especially if pressure is involved.

Randy

The additives you are talking about work by softening and swelling rubber seals, and may in fact slow or stop your current leak, for awhile. The problem is that the additive will also soften and swell all the other rubber seals that are not currently leaking and might create some new leaks. Then again it might not and you'll be good to go, For awhile.
Point being, at best the additive is at best a temporary patch and not without some drawbacks or risk.