Engine has less than 1k on it. Went back all stock, except a slightly better cam, but well within acceptable parameters(according to the guys in the v6 forum). Timing is set dead on. My oil pressure would act all funky, so I replaced the sending unit...same thing. Installed a mechanical gauge in place of the old sending unit to get a more accurate reading. Under throttle, 20-30psi, sometimes as high as 40. Idle, 5-10psi. Car bogs like crazy during these times, but will not stall. When the engine was first dropped in, the timing wasn't set entirely, and the oil pressure would act funny here too, and the car would stall. Setting the timing properly fixed the stalling issue. I think that's about all the information I've got. Help please!

 

well i hvae one suggestion i could be wrong but i know i had bad oil pressure when i put a new cam in my good ol TA but im preety sure i had nicked a cam bearing putting the cam in though .. thatll drop your oil pressure..... i didnt have a problem with bogging but thats how my oil pressure was too i always had to idle it up just a bit high

 

hey guys im havijng issies either with my used digital dash or my oil sender.

what should my readings be for just the igniton on and engine warmed up at idle?

 

I watched my dad install the cam, which he's done many times before on various engines through the years, and he was extremely careful about putting it in. He said it would take a lot more than just a minor bump to nick the bearing.

Some more info... I took the car out and got it nice and warm... hit some heavy traffic by accident and did a lot of idling around. It would routinely stay at 5psi at idle, but sometimes would drop to zero with the RPM around 400 or so.

It seems to me that there's a larger issue causing the oil pressure to not be anywhere near where it should be and the car bogging, since the two aren't exactly related directly.

 

Anything over 5 psi at idle is considered OK, but for a new engine you should really have 20 or more at a warm idle. Did you measure the bearing clearances? What oil are you using? Do you have a cheap Fram filter on there?

 

Measure bearing clearances, no I did not. I had the bearings installed by the same machine shop that polished my crank, though. Used stock sizes. I'm using 5W30 Penzoil, and yes, a Fram filter.

 

Change the filter first. Get a Hastings or NAPA gold. Not all Frams are bad, but many of them are. It's a cheap place to start. Have you talked to the machine shop about your low pressure?

 

Alright. I wasn't aware a filter could hurt oil pressure.

 

I never understood why some people rebuild their engines and don't machine down the crank and go with oversized bearings. I don't care of it looks like the journals are "within spec"...any kind of out of roundness is enough to mess things up.

It sounds like you cheaped out on the rebuild and now it's going to cost you more. Good luck with that.

BTW, run some 20w50 and Lucas oil treatment. Should be a good band-aid solution until you can "truly" rebuild the engine.

 

Because I trust what my dad and uncle say, who have been building good engines all their lives. True, they are the old school kind of mechanics that straighten frames with a tree and train and adjust timing by ear... but for rebuilding an engine to stock, they know what they're doing. My machine shop also said polishing would be suitable for my crank.

 

It has been suggested that perhaps the fuel injection could be causing problems? I don't see how, but then again, I don't know a whole lot about EFI.

 

The shop that dynoed my engine told me to get rid of the Fram filter because he has seen them cause problems like you are describing. I have no idea if there is any truth to it, but less than $5.00 and five minutes work would be worth it to at least rule it out.

 

I did some quick research online concerning recommended oil filters and compared that with the list of options available at my local parts store. I ended up picking up a Mobil1 filter and installed it last night. Oil pressure was noticeably better, but by that, I mean that oil pressure now sits at 7 at warm idle instead of 5.

What exactly should I be asking my machine shop? I spoke to my dad on the topic last night. He's said he built his first few engines under the direct supervisor of his grandfather--a career machinist of 35 years. Everything he was doing to build the engine with me was what was taught to him by his grandfather. The machine shop that did my work was the same shop his grandfather worked for, and everyone still there worked with the man. I guess you could say I kept it in the family. Anyways, my dad said he has always had his cranks polished and turned, but turning is never hard enough to require oversize bearings.

All my parts are stock. A new oil pump was also installed at the time of the engine build. Could it be that I got a bad oil pump?

 

It's unlikely that your pump is bad. They are very simple devices. There is no way to tell what's going on without opening it up and taking some measurements. I would guess that your bearing clearances are too wide for the stock pump to keep up with.

If it were me, I'd either put in a high volume pump or just run 10-40 (or put a can of STP in to thicken it up a bit) and run it. Odds are it will be fine as long as you get 20-30 psi at cruise speed. I have a '68 Camaro that only gets 7-8 psi at idle and it's been that way for years.

 

Aye, I understand what you're saying, but I would think this engine should be doing a lot better. For only 600 miles on it, it bugs me. A lot. It's not like pressure is down but the car is otherwise fine--it refuses to idle properly at all. If it idled just fine, I wouldn't be so worried about it.

I'll pick up a can of the oil treatment tonight after work and see if that helps any.

 

The idle is a different issue. Speaking of, what RPM are you measuring the idle OP at?

 

"measuring the idle OP at"? Not sure what you mean there. Do you mean idle oil pressure? 700rpm(warm) =5-7psi, 500rpm(warm) = 0psi. Cold start is 40-50psi. High idle(1k, cold) is at 10psi.

 

Hmmm, the 0psi at 500RPM would worry me. So the right thing is to pull it out and fix it. Plastigage the bearings and probably have the crank turned and reinstalled with oversize bearings. You could still try a high volume pump first.

 

Just got off the phone with the machine shop... crank was ground 10/10, which means I have the wrong bearings installed.

So what exactly does this mean for me? Do I need to be pulling the motor ASAP to replace the bearings, or will it be fine? I intend to be putting quite a few hundred miles on the engine between now and next spring. It's going to be quite cold here real soon and I won't be able to rip it all back apart until March at the earliest.

 

Ah, now it makes sense. You really should replace the bearings and make sure the journals are still OK before you drive it again. Apparently no one checked the clearances when they assembled it. That's engine building 101. Always check the clearances. Plastigage is cheap. Painful lesson, but all us car guys learned things the hard way a few times. Those are the things you'll never overlook again. Good luck.

 

Alright, this next question is going to get me a 0% grade in Engines 101...

I can't remove the engine until, at the earliest, January. My roommates are going home(exams are over) and this is my only car. They'll be back in January and I can start bumming rides. Let's assume I run on it every day, 10 miles total a day. What is the worst case scenario? Burnt main bearings(turns it it was actually only 10 mains, standard rods), burnt crank. Will require new bearings and turning the crank again(or another crank). Does anything else stand to have any major issues?

 

The problem will be the metal that can get into the oiling system from the bearings. It can get uglier if a bearing spins. You'll probably be OK if you put a can of STP in the oil, keep the RPMS up when it's cold and drive it easy.

 

My dad suggested something called "engine honey" to help thicken it up. Should I perhaps take SteelTownMadDog's idea and run some super thick oil?

 

That's pretty much the same stuff as STP. You don't want to run anything too thick if you're in a cold climate. You can have starvation problems because it's so hard to pump when it's cold.

 

No colder than mid teens in the dead of winter during the day. I'll pick up a bottle of STP tonight then and hopefully be able to fix the bearing issue next month. I hate doing this to my poor car.