here's the deal, my friend's ls/vtec engine(b18b bottomend, and gsr head) is having some oil pressure problems. vtec was engaging at about 5-700 rpms higher, than what was specified on the ecu chip. we thought it was the size of the oil line feeding the head, so we bought an oil line from flamenco-t(stan) and that didn't change anything. since he was going to install an oil gauge, we went ahead and did that to get some answers. after the instal, the oil pressure look to be in order, 10 psi at idle and 50 psi at 3K rpms. but as soon as the car hit the road, the oil pressure would drop down to 40 psi above 3K rpm, and at idle it would be between 5-8 psi. we consulted the factory service manual, and determined that the oil pump was fulty. today we went ahead, and replace that pump with a brand new gsr oil pump! but the proble is still there, my question to you guys is what could be keeping the oil pressure below operating levels? what else other than the oil pump, can make oil pressure drop in the engine!

 

any thoughts?

 

i have a similar story and would like to hear anyone's thoughts.

i have a 97 asccord exr, 2.2 F22B1 SOHC. shortly after i bought it, the oil light came on. after checking the pressure with a gage at the sensor point, we determined the pump was likely bad. a few days ago we started in on replacing the pump.
when we removed the valve cover we found a ton of dried sludge over the rocker assembly, so picked up some engine flush for after the job.
next, we tried to remove the crank pulley (another story) but ran into the problem of not having the right tool. we decided that since we couldn't do that job until we got the right tool. that we'd try flushing the engine just in case the problem was being caused by the sludge. we drained the engine, filled it with fresh oil, a new filter and a bottle of quality engine flush. we ran it at idle (as per instructions) until it reached themerature, then drained the oil. next we filled it with fresh oil and a new filter and again brought it to temp. at start-up it ran 20psi @ idle and as high as 60psi @ 3000rpm, but as the oil warmed up, the idle pressure dropped to less than 10psi and would barely raise higher than 10psi even when rev'd. we drained the crankcase and inspected the main bearings, rod bearings etc for wear. we found nothing that indicated enough wear to cause low oil pressure.
it was looking at this point that it was the pump for sure, so we got our hands on the pulley-holding tool and went to work replacing the pump. when we were done, the cold idle pressure was 40psi and at 3000rpm we got more than 80psi. as the oil heated the idle pressure fell to 15psi, but 3000rpm would still bring it up to almost 80, so we figured we had the problem fixed. we put everything back together and checked the pressure again, and all was fine.
i live about 30 mins from the garage we used to do the job. on the way home from the garage, less than a mile from my house, the oil light came back on! we put the o.p. gage back on and found the oil pressure was dropping to 7psi at idle again.
after verifying there seemed to be no bearing damage and having replaced the pump, filter and oil (10w30), and doing the thorough flush, we are absolutely stumped. i have had a few people tell me 100% synthetic oil might cure the problem, but i am not convinced it will...i mean, the low pressure light came on for a reason.
other than switching to synthetic oil, does anyone have suggestions that might explain/cure this problem?




Modified by ec_accord at 4:20 PM 4/18/2004

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by ec_accord &raquo;</TD></TR><TR><TD CLASS="quote"> i have had a few people tell me 100% synthetic oil might cure the problem, but i am not convinced it will...i mean, the low pressure light came on for a reason.
other than switching to synthetic oil, does anyone have suggestions that might explain/cure this problem?
Modified by ec_accord at 4:20 PM 4/18/2004</TD></TR></TABLE>dude, sorry to hear about your oil pressure problems, but in my case we are using mobil 1 synthetic oil so you can rule out the synthetic theory! anyone care to help out with this, i might start to take the block apart by the end of the week!

 

would like to know too, dont have the problem but one day it might come across.
bump

 

could be a clogged pickup tube. Take the oil pan off and examine that pickup tube. This happened to me before. There was massive black build up in the pickup tube. Ended up going through 2 heads, because I didn't take 30 mins to take the pan off and check the oil pickup tube. Also check the oil pressure sending unit on the back of the block!!

 

yeah....when installing the new pump we also thoroughly inspected and blew out the pick-up tube, even though it looked fine. i'm 100% certain we can rule that out.
we also removed the sending unit and installed a temporary guage to monitor the results. we even swapped for a second gauge just in case the first one was faulty, and still got the same readings.

on a side note: if anyone ever needs to remove the crank pulley, i strongly recommend either buying, borrowing or renting the hex tool for holding the crank from turning. we tried everything from a 3/4 impact gun to a 4' pipe on a breaker bar when we first tried to remove it, but with the right tool, we were able to break the bolt with a breaker bar without the pipe on it! i've made the tool to have for future use but have seen them on the web for as little as $35.00...a bargain at twice the price if you have limited patience like me! lol

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by SleepyHF &raquo;</TD></TR><TR><TD CLASS="quote">could be a clogged pickup tube. Take the oil pan off and examine that pickup tube. This happened to me before. There was massive black build up in the pickup tube. Ended up going through 2 heads, because I didn't take 30 mins to take the pan off and check the oil pickup tube. Also check the oil pressure sending unit on the back of the block!!</TD></TR></TABLE>
the pick up tube looked fine, but i will take the oil pan off again just to check it! we're getting a low oil pressure reading from, a autometer oil pressure gauge!

 

Curious what this could be too.

 

i hope i find an answer, my friend is becoming fustraded with his ls/vtec! the only two things that i think, will affect oil pressure in the block or head will be the oil orifice in the middle of the second cam cap(middle one) and the oil control orifice on the block between the # 2&3 cylinders!

 

i've pretty well narrowed it down to a bad bearing, even though our first look showed no indication of wear. i suspected an orifice at first, but a plugged gallery keeping oil from the top end would not cause a drop in oil pressure and if a passage back down were plugged i'm pretty sure something would have seeped by the valve seals by now and been visible with the exhaust.

so...
first up will be rod/main bearings as they are easiest (and least expensive) to replace. if that doesn't improve things we'll turn to the head, and if the problem still remains, we'll pull the engine and do the balance-shaft bearings.
i probably won't get at it for a couple weeks but i'll post my results here.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by ec_accord &raquo;</TD></TR><TR><TD CLASS="quote">i've pretty well narrowed it down to a bad bearing, even though our first look showed no indication of wear. .</TD></TR></TABLE> i did run this theory by a friend of mine who's a honda technician, he told me that more than likeli if it was a bearing we would be hearing sounds from the bottomend! i'm going to start pulling the head off tonight, and also check the oil pick up tube!