Oil leak on a 940

Kirby J · Post by **Kirby J** » 06 Sep 2011, 10:54

Its raining in Nashville, so of course my car decides its time to act up! While driving my 93 940 Regina, 415K miles, I began to smell oil burning. I thought that it might be time to replace my filler cap gasket, but the weather was terrible, and customers were waiting, so I continued to drive. No warning lights, no temperature spikes, but lots of smell. After about 40 miles of in-town driving the smell was getting pretty intense, so I pull over and take a look. The back of my engine is covered in oil. The knock sensor is full, and oil has dripped down onto the exhaust manifold, at least this explains the smell. I am down 2.5 quarts. The front of the motor is dry. The top of the valve cover, around the filler cap, is clean. And no smoke out of the dipstick. If it was the RMS, wouldn't everything be contained in the bell housing? The valve cover gasket could be the culprit, but it has never leaked before. So my question is, What else is back there that could explain all the surface lubrication on the back of my engine. It is still raining, but when it stops I would like to know what to look for.

Kirby J

Post by **jersey240** » 06 Sep 2011, 11:54

Check the rear cam seal - http://www.brickboard.com/RWD/index.htm ... show_all=1
That link has a photo, plus good information about why the seal blows out [clogged flame trap], and arguments for and against using a rear cam seal retainer [including danger of blowing out other seals].

Kirby J · Post by **Kirby J** » 06 Sep 2011, 12:57

So this would be what it looks like after I remove the knock sensor? Thanks a lot for the info. Now if it will quit raining!
Kirby J

Post by **jersey240** » 06 Sep 2011, 18:19

You're right, once you take off the distributor cap I think that's what you'll see. I forgot the back of the 940 engine has that—the 240s have nothing mounted on the rear of the cam, so the cam seal retainer they talk about on the brickboard link doesn't apply to your 940.
You're welcome, and good luck.

Kirby J · Post by **Kirby J** » 08 Sep 2011, 15:34

Today I removed the cup-shaped attachment located behind the camshaft. Inside I found a fair amount of oil, and the rear cam seal. It looked to be undamaged, so I popped it back in and tapped it with a rubber hammer to be sure it was in place. I did not even know I had a seal back there until asking for advice on this site. Thanks again!

Kirby J

Post by **jersey240** » 09 Sep 2011, 09:08

You're welcome - Please note that I am NOT an expert, just learning about a lot of this stuff myself.

But if that were my car, I would replace the seal with a new, genuine Volvo one.
part number 1336763
Red aftermarket engine seals have a bad reputation. Since the aftermarket seal is only $2.50 at FCP, it shouldn't be too expensive to pick up a genuine one. Maybe $10-$20 to keep your 940 alive.

Also, if I understand correctly, you need to address the flame trap / PCV system since it blew a seal. Otherwise, it'll just blow out again.
http://www.brickboard.com/FAQ/700-900/E ... A_Treatise

EDIT: Also just found this post. Not positive that the instructions will apply to you 100%, but at least the explanation of why you blew a seal is concise. http://forums.turbobricks.com/showthread.php?t=86866