Hello everybody, new member here from Winfield, Illinois, USA. This is my second Volvo 1800, a '71 1800E. My son and I flew one-way to Baltimore and we drove it home to Illinois. When we checked the oil prior to driving home, we found that it had been over-filled by at least a quart. I also found that the oil trap / breather had been plugged, and promptly removed the blockage. Right or wrong, we drove 700 miles and the oil level gradually dropped to about a 1/4" above max. The car ran really well, oil pressure light works but never came on with engine running, oil pressure gauge indicated good pressure range.

A few days ago, I drained the engine oil but left the filter installed until this morning. When I removed the filter just now, it did not spill more than a few drops of oil and appeared to be completely empty. I have done a lot of oil changes through the years but have never experienced this until today. The old filter was a WIX.

Could this be caused by the crankcase becoming pressurized due to the plugged breather? The oil filler cap was still connected to the intake manifold, BTW., would that prevent crankcase pressurization?

Thank you for taking the time to read this and for any advice. On a side note, I am trying to re-plumb the breather hoses correctly but am having trouble finding the correct intake end fitting. There is a nipple on the underside of the intake manifold that has a vacuum cap installed, but that is smaller than the nipple on the breather. I believe that I am missing a pcv valve, which might have a big side and smaller side?

I agree with John S that the problem was likely due to a defective drain back valve or something preventing the drain back valve from sealing completely.

I assume that the plugged bit that you are refer is the flame trap on the side of the engine? If so, as long as you have the hose from the oil filler cap to the intake manifold, you won't be pressurizing the crankcase. It will run at a vacuum at idle; but, because the flame trap was plugged, you won't have any airflow which means that you are likely accumulating moisture and crud in the oil - good reason for that oil changed.

In 1971 I think the 1800 came with both D jet and carb options? If you have D jet, the hose from the oil filler cap goes to a fitting on the top of the intake manifold. That fitting has a flow restricting orifice in it, no PCV valve. I can't help you with the carb arrangement.

As a heads up, if you have Djet and if the flame trap was well and truly plugged, cleaning the flame trap will allow air to flow through the crankcase and into the intake manifold. This increased airflow is not a problem; however, it will likely cause the engine to idle a little faster than it did when the flame trap was plugged. Not a problem, just means you have to drop the idle speed a little bit.

Yes, It has D-Jet fuel injection. I will clean the flame trap as you suggest and try to connect it to where it should go on the other end. I took some pictures and will try to post them from my phone soon.

Thank you for the advice.

Geoff

Check out the last picture in post #137 in this thread. Its a 142; but, its a B20E engine - same as yours. You can see the hose from the oil filler cap going over to the nipple on the top center of the intake manifold. The hose from the top of the breather / flame trap box should go to a fitting on the air filter box somewhere (so that clean air enters the engine). In the photo, you can see the hose from the breather / flame trap where it crosses the engine just in front of #1 injector and to the left of the oil filler cap. It goes to the bottom of the air filter housing which is that round black plastic thing in the bottom right of the photo.

I couldn't find post #137 (where are the numbers?) On my tablet, will try again on my computer once I'm at home. Having trouble adding images from here as well, sorry.

It would have helped if I had provided the link:

http://forums.swedespeed.com/showthread.php?201780-What!-Another-142-Project-Car/page4

The post number is on the top right of each individual post.

Got it now, thank you for the link. I wish my engine was that nice looking, 142 guy! I just looked at the air cleaner (home now) and there is a large bolt shoved in a hole just before the flex hose that connects to the intake manifold. I bet that is what I was looking for, but I will need to find a way to connect the hose. Thank you for your help!

Sounds like a similar arrangement to the 140. On the 140, the hose from the flame trap just shoves into the hole in the air filter box. There is no fitting, it is just a really tight fit. If you have a heavy wall rubber hose from the flame trap you may not be able to force it in to the air filter box without some 'shaving' of the hose. I need to spray my hose with silicon lube to get it to go into the hole.

As an alternative, you can ditch the hose connection to the air box and just put one of those little K&N style breather filters directly on the flame trap.

Will try the connection first, and fall back on the breather filter if it won't fit. I had purchased one of those filters but it didn't look like it would fit onto the flame trap so I returned it.

Geoff

Geoff;

I agree with others that drain-back check valve was likely not sealing. The Volvo OE filter supplied by Mann, whether with an official Volvo logo or simply the Mann manufacturers label, are not too expensive, and have never failed to satisfy me...oil system is the last place I want to scimp!

Reference info for PCV sys: http://www.sw-em.com/pcv_diagrams_and_notes.htm

Cheers

That page is a great resource, thank you Ron! I already had a link to your excellent service notes page on my 1800e blog, and just added another to your tech articles page.

Geoff

Geoff;

I'm glad that the info is helping...that's the whole point.

I used to spin a new oil filter on at an oil change (empty!), then CRINGE for those first 3-4 seconds after the first startup, while it was filling and the engine was knocking terribly for what seemed an eternity!...I couldn't take that, so now, I ALWAYS fill the filter before installation...it takes a bit of technique and experience NOT to make a mess when installing a primed filter, but pressure is up within a second after starting, and there's no more dreaded knocking on first startup! ...and that's what a leaking anti drain-back check valve would cause at EVERY startup!...no thanks!

Cheers

Thanks Ron, and I installed a Mann filter because the car came with a couple of them. Will get more!

Thanks Ron, and I installed a Mann filter because the car came with a couple of them. Will get more!

Wix is a quality oil filter, but I would guess this one has a bad check valve, or debris under it. The intention of the check valve is to prevent oil from gradually draining back into the engine. They are made of rubber, and you can see them when you look at the attaching end of the filter.
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john

Thank you, John. I hope that was it, because then the new filter should do the trick.

I'm certain that was the problem. There is no internal oil passage between the oil pump output galley and the oil galleys serving the engine. The oil flows into the filter and then into the oil galleys. There is an internal oil pressure relief in the filter. It allows, when the oil pressure is high when the engine is cold, for oil to flow into the filter and not go through the filter media. The oil still has the enter the filter to get from the oil pump output galley to oil galleys serving the engine.
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john