Just finished rebuilding the D15b2 in my CRX, and I am noticing a weird problem. Noticed an oil light, so I installed a pressure gauge in it's place to get a better read on it.

Oil pressure starts at 40 when you start it (warm), and drops with every rev after that. As the revs die down, the oil pressure goes down with it. Maybe by about 5 psi with every rev. Driving down the road, the gauge will eventually hit 0.

At my wits end with this car. Any ideas why this may happen?

 

Seems that your external gauge is confirming the stock sensor. Did you reuse your oil pump? Oil pick up? And how extensive was your rebuild? Reason for rebuild?

 

We did (by we, i had some help) did reuse the oil pump. We did new rings, all new main and rod bearings, pistons were fine so we polished them, newer head, and all new gaskets for just about everything (oil pan, valve cover, head, etc.) and new head bolts.

The rebuild was for a missing cylinder, which I got back after rebuilding it. It runs on all 4 now.

 

Also, not to seem like an idiot, I wasn't questioning the validity of the light. Sorry if I came across that way.

The pressure is just behaving very oddly to me, where it holds steady at the start, and drops with every rev.

 

No worries, all info is worthy so I'm not judging by any means. Anyways, by chance during your rebuild did you touch the oil jet to replace the o-ring? If so, is it safe to assume you put it back? Also which head did you reinstall since you mention it's a newer head? For the bearings, did you go standard size? Or did you go OEM and do the individual color coded pieces? Did you measure all the journals on the crankshaft?

 

We did not measure the journals. I just used standard sized bearings. The newer head is just a head from a donor D15B2 with significantly less miles on it, and I didn't touch the oil jet, though the one who was helping me most likely did, and I'm sure he put it back. (only because my parts bin is empty, meaning we put everything back)

I am going to drop the oil pan, clean out the pickup screen and look for a check/pressure valve that I've heard can be the cause of issues like this. I'll clean that out too. I'll report back after that.

 

Gonna see after I put this back together. Taking a break right now, but the crap that came out of the oil pickup was just disgusting. It was way clogged. There's where all my pressure was going, most likely. Oil just couldn't pass through it. Wil update after reassembly!

 

Good to see progress is being made. Pretty certain all will be well now

 

Thanks for the help! Cleaned it all out, topped the oil off, broke in the new rings, and it runs like a dream. Thanks again!