NoWorries

I have a brand new 355 with 32 hours and 900 miles on it. It still maintains 60 psi of oil pressure at idle. But, my problem is when I start up, I get pressure immediately, about 10 psi, but then it takes about 25 seconds to get to 60 psi. The guage is mechanical, and goes up when rpms go up.

The oil pump a Melling high-volume pump, I can't remember the part number, but I took it apart to check clearances and they were perfect.

I'm running Valvoline 10-W30, and the temperature has ranged from -6 F to 40 F, but the temp doesn't really seem to affect how fast the pressure rises.

Another thing I've considered is that the guage has already worn out. It used to be quick and responsive, but now has slowed down a bit.

Last thing, I'm using a copper line instead of the vinyl one that came with it. Is this wise? I've heard that although it seems that copper should last longer, its more prone to breaking than the vinyl line. Which do you recommend?

Thanks for any light you can shed on the subject.


[Modified by NoWorries, 12:45 AM 12/24/2001]

Techno

My brother had the stock spaggetti hose break on him, when he was wearing white! He didn't like the episode or cleaning oil off the rug. I haven't changed mine but I want to go to a braided overkill line. I've heard aluminum and copper can break from vibration, you'se takes your chances.

Your pressure thing seems to be more temperature related. Try pouring some of that oil at 40* and watch how slooow it pours.

clem zahrobsky

if the oil filter bypass in the filter adapter is plugged this will happen because it takes a while for the oil to get through the filter. when oil pressure shoots right up to the top it is going through the filter bypass.

gerry c

Have you changed the oil filter recently? That is what I would try first as one my old Blaser if I have not changed the filter in a while (10k miles or so) it acts like that. At 900 miles I would probably be on at least my thrid oil/filter change. A lot of "junk" can come off a fresh rebuild.

Blake-73

I agree with the oil filter bypass being plugged as the most likely problem.

Good luck!

Blake-73

NoWorries

Thanks for the replies. I'm 400 miles into my third oil change, I've just recently noticed this problem. I'm running a K&N oil filter, and the bypass was cleaned when the motor was apart.

I'm planning on doing the next oil change at 1,500 miles, I'll pull the bypass and make sure its working correctly then.

Until then, I'll just give it a little more time to warm up. I tested it after letting the oil get to 180 degrees, I shut it off, let oil pressure completely bleed off, then started it again. It rose faster, but its still slow.

My 1984 Blazer with 167,000 miles on the rebuild makes pressure immediately, thats why I thought this was odd. The Blazer has a stock pump with blue-printed bearings.

Thanks again, you guys have been so much more helpful than the C4 guys.

NoWorries

Hey guys, I went into Autozone(closer) and asked for an oil filter bypass, and even described it to the guy, and he looked at me like I was nuts.

So I drove all the way across town to a NAPA, he at least knew what I was talking about, but he told me I'd probably have to get it from the dealer. I've had bad luck with the only dealer close to me, and I refuse to give any business to them, as weird as it may sound. I'm moving back to the big city on the 12th of January and could pick up a new bypass then.

Anyways, how could the bypass go bad? Does the spring wear out? I cleaned it pretty well while it was apart. Does it matter which way its bolted on? The book I have said it didn't matter, and I looked at it for a while and decided the book must be right, so I just bolted it on. Could I have it backwards?

Thanks. :)

Phlash

Some filters have a bypass, long ago when I drove Fords, I found that Fram didn't give the oil pressure that the Motocraft filters did. Maybe the K&N isn't for you.

Phlash 72 BB Roadster :seeya

Techno

The oil by pass serves 2 purposes I'm not sure if youse guys understand it right.
IF the filter is plugged the oil is then by-passed and pumped into the engine without filtering.
IF for some reason high oil pressure is obtained this releases it, A plugged oil filter would cause high pressure as sensed by the by-pass. Very high pressure can do things like blow the filter apart. Or ruin the bearings. It acts as a pressure regulator by releasing pressure, although I've seen mine go pretty high.
It's main use is for people who don't change their filter so the engine gets oil. It can be eliminated so all oil gets filtered. but this means you have to do what I'm sure everyone is already doing, taking care of the oil changes.

I think on BBs with 4 bolt mains this by-pass is under a plug above the filter. Forgot its been a while. A little different than the others?