I may have a low oil pressure issue with my 1983 242. The gauge reads 2 bars of pressure on a 5 bar gauge at start up. With a hot engine at idle the pressure reads less than 1 bar and the oil light comes on. Cold engine or hot at 1200 RPM or above the gauge reads between 2.5 and 3 bars. I have been told on the forums to test the pressure with a mechanical test gauge. Is it better to purchase a mechanical test gauge to test for a bad oil sending unit or install a permanent mechanical oil pressure gauge on the dash.


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1983 242 GLT / 1991 244 / 1993 245 / 1999 v70

Because of the "leak" issue that the others have acknowledged, you'd be better off using an electronic gauge in the passenger compartment (you might even want to make it permanent) with the electrical sender on the block so that only wires extend through the car. If you make it permanent, you can always fit a T-fitting (although be careful for clearance) as well, so that the original pressostat (pressure switch) still works the dash warning lamp.

The pressure gauge I bought to test through the port on the front of the B230f was from Harbor Freight and it leaked like crazy leaving a trail of drops up and down the street and into the driveway. FYI

Thus the issue with a mechanical gauge...potential oil leaks at the engine and inside the car. You have to run a tube from the block to the gauge in the car, which is way more of a pain than running a wire...or even getting a new sending unit for your block. It would seem like a waste of coin to get a mech gauge just to test your sending unit vs. making it a permanent install.

Hi,


The block thread on the engine is British Standard Pipe thread, which is different from the regular thread. I was able to find a Swagelok fitting on eBay and used a flexible stainless steel braided Teflon (Swagelok also) on the adapter into a bulkhead fitting I installed on the firewall. From there, 316 SS tube into the gauge.

Expensive, but it is not going to leave me stranded like the plastic nylon crap.

If you are having pressure problems, the first place to look is the oil filter. Is it Mann or Volvo branded? The check valves in filters like Fram often are defective out of the box and can cause problems. The other likely culprit is the o-ring on the oil pump lift tube.

http://www.unm.edu/~goatman/gauges.jpg



Goatman

Thanks for your help.

I just changed the oil this morning. I changed the oil this morning. I used Mobil 1 10w30 and a Bosch branded oil filter. The first time I started the car afterwards I got all excited because the gauge read 4 bars on a 5 bar gauge. Unfortunately once the car warmed up I got a 2 bar reading at 2500 RPM and less than one bar and a lit oil light on the dash at idle.

I know the next step is to use a mechanical gauge to check oil pressure. I figured installing a quality mechanical oil pressure gauge would do. I can find VDO gauges at a reasonable price. I will use your suggestions on the install of the gauge.

I hope I get lucky and get good readings on the mechanical gauge. I am dreading the next step of addressing the oil pump o-ring issue.

Again thanks
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1983 242 GLT / 1991 244 / 1993 245 / 1999 v70

My own analysis of this condition sidestepped the "mechanical gauge verification" because I had some evidence (based on some 20W-50 Castrol bottle found in the trunk) the PO left me this problem. I think you'll find the B21 and B23 cars use 1/8-27 NPT (National Pipe Thread) with a standard taper that all the gauges of that era used -- nothing exotic.

The square o-ring at the delivery pipe seems to be a common problem. Here's how I dealt with it: Volvo 240 Oilpan

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Art Benstein near Baltimore

Women and cats will do as they please, and men and dogs should relax and get used to the idea. -Robert A. Heinlein

Art,


Since I worked as a salesman at a plumbing supply, I had access to all the common fittings. The soft brass 1/8 NPT would screw in only a couple of threads. The BSP stainless fitting went in perfectly.


Goatman