My rear main seal appears to be hemorrhaging oil. I have not looked at an engine manual for this yet. Can anyone tell me from experience roughly what this job will cost meto hire it done? Is there any way (hope against hope) to effect this repair with engine still in car (yes, I remember the days when you could swap out the rear main on a small block chevy). If removal is necessary, does it come out from above or below on this car? Are there any "how to" threads here?

Thanks.

 

Most places charge between 8-10 hours to have it done.

It can be done with the engine in the car but you need to make a cradle to support the engine. The subframe needs to be removed.

 

Thanks,

What about the crankcase pressure? I've been doing some looking and it appears that this is sometimes caused (or made worse) by a crankcase ventilation problem. I did a quick check, and noticed that I do have postive pressure in the crankcase - smoke blows out of the dipstick tube when I pull the stick, and it also blows smoke out of the oil fill cap when removed. Shouldn't there be negative crankcase pressure?

What's the fix for this? I'll do some looking, but any advice is appreciated. I suppose I really need a good manual and need to spend some time reading it.

Thanks again.
Keith

 

You should just replace the entire PCV system. Buidup in pressure (clogged PCV system) will lead to the RMS blowing out.

 

I read that your RMS may stop losing oil if you fix the PCV issue.

 

^I think it actually blows out. So even if you no longer have the pressure pushing out, you've got a hole for oil to get out from.

 

Hmmm. I've never seen a crank seal "blow out". Seems like that would take an awful lot of pressure (like many psi). I've heard folks say the leaks may subside if the PCV system is working right. But, with a high-mileage car, I'm doubting it will stop altogether. But I'm willing to give it a try and see if it might become manageable. I've also heard of some product that supposedly brings brittle seals back to life. Can't remember what it's called, but you put it in your oil, and supposedly it will help heal your seals. First the PCV fix. Time to hit the books.
Thanks all.
Keith

 

Maybe then I've been thinking about it wrong this entire time then. Every RMS problem I've heard, the owner replaced it.

But PCV has to be done either way.

 

They usually won't blow out of the hole.

 

Hi Keith,

>I've also heard of some product that supposedly brings brittle seals back to life. Can't remember what >it's called, but you put it in your oil, and supposedly it will help heal your seals.

Negative. I would not recommend any "Stop-leak" kind of stuff into Volvo. They may fix the problem for a few days or a few weeks at the longest, but may do more harm than good.

As for PCV, I would get parts and either work on it yourself or find an independent shop that specialises in Swedish/European makes to avoid screw ups. If you have a basic set of tool, it wouldn't be that difficult, but since you have to remove the intake manifold, be sure to order new intake manifold gasket, should you decide to attack it yourself.

http://www.fcpgroton.com/volvo850oiltrapturbo.htm
http://www.fcpgroton.com/volvoeng850engine.htm

Note, that turbo & non-turbo use different PCV kits, as well as different intake manifold gaskets. Also, someone noted that FCP Groton's got the illustrations for the PCV kit backwards, so call them to ensure you're getting the right parts, if you decide to get parts from them.

I hope this gets you started.


JPN

[IMG]local://upfiles/6892/C8304236FBA842FEB711098A378D56C5.jpg[/IMG]

[IMG]local://upfiles/6892/68E53D3AFF7945489175C0637D0A5E35.jpg[/IMG]

 

Thanks for the heads up JPN. Hmm. I didn't realize the PCV job was going to require pulling the manifold. Oh well, if it needs it, it needs it. Sure is easier than doing the main seal job. When working properly, should I have negative pressure on the crankcase - i.e. will the smoke stop coming out of the dipstick tube?

Also, I think tech said something about being able to do the seal with the engine still in the car. Is this the recommended way to go about it? Do you know of any online "picture stories" or other guidance for the job?
Thanks again,
K

 

^No. Positive Crankcase Ventilation (PCV).

 

Hi Keith,

The purpose of the PCV system is to keep away pressure buildup in the crankcase, by extracting the blow-by gas (mostly part of combustion gas passing past the piston rings) from the crankcase and back to the intake. The intake suction draws this blow-by gas and put it back into the combustion chamber. This way, the pressure build-up in the crankcase is prevented. Many mfgs use PCV valve, which is a simple plunger mechanism, but Volvo seems to use unique design of the PCV system.

Yes, some seals can be replaced with the engine in place, such as the camshaft seals, and probably the front crank seal, but the rear main seal requires the engine & tranny to be out, as this requires separation of the engine & tranny. A gentleman by the name of Robrike has performed this service a few months ago and has posted an excellent thread with photos.

I hope this helps. And as usual, Tech would be able to give you more accurate replies.


JPN

 

The engine doesn't need to be removed it there is means to support the engine.
The subframe needs to be removed and then the transmission can be removed.

 

Tech, I sucked again.


JPN

 

No alot of people will choose to do it that way.

If you have an engine cradle it can easily be done without removing the engine.

 

Sorry to have been away for the last week, I have been swamped and have not touched the car.

Tech and JPN are both right, you can replace it by removing the transmission and subframe or you can pull the engine and transmission together from above. I elected to pull the two out from above. I wanted to replace the timing belt and components to it and all the hoses. In hindsight, supporting the engine in a cradle like Tech said would be the best way if you are just replacing the RMS alone. I think HarborFreight sells a tool that spans across the front fenders and has chains to attach to the engine so you can drop the subframe. From there you can pull the transmission and get to the RMS. I am still putting mine back together and hope to be almost finished by sunday evening. I have some people waiting to hear how cleaning my PNP switch went. The dealer still does not have my alignment tool but they have convieniently charged my credit card for it. [:@]

If you just want to replace the RMS I would drop the subframe. You can also tackle the PCV system from above pretty easily. It was cool to pull the engine/transmission together and see what all was there and check everything but it was ALOT of work. I had pretty good experience with working on repairs, etc but had never pulled an engine. The Haynes manual was great on how to do it. Plus Tech gave me some great tips. Once I get it all together I plan to try to organize my pictues and put together a mini FAQ.