This all started with the oil light flickering about 20 sec after startup and then going to bright red. I checked the oil level and replaced the oil filter and that was all good. The next thing was to check the actual oil pressure so I took the car to my mechanic and he tested it and told me I only had 5lb and don't drive it. He was too busy to work on it today, maybe later this week. The engine is an all new 400 with a mild cam. It's been run maybe 2hrs. I can't get in touch with the engine builder. Any suggestions.

Suggest hunting down the engine builder. Can't get in touch because he's busy, on vacation, or closed the shop and split to Mexico?

Having the 2nd mechanic check it out might total void any possible warranties with the original builder if that "investigation" involves opening the engine up.

Did you have a low oil pressure light previous to this (any time during the previous 2 hours of run time)?

Actually I think my mechanic is a better engine builder. The engine builder I used did the engine in my Camaro Z28 and it was a great engine. Not so great on this engine.
No oil light previous to this. I did tell my mechanic that I had a clicking sound at higher RPM's and he reset the timing and it went away.

I'd run 20w50.

Too many people "think" 5w30...

What weight, brand, type oil using?

5 PSI is fine hot. What is your PSI on cold start up? fluctuating? fluttering?

Should be 1 PSI for every 100 RPM. I have 5-7 PSI at idle and not worried one bit.

Also consider variations in gauges.

The oil I used is Pennzoil, not sure on the weight. When the engine has more miles on it I'll use Mobile 1. "5 PSI is fine hot" is interesting but my oil light is on. My mechanic doesn't really want to pull the oil pan but I think it's the next step.

Well...

How did he check your oil pressure?

I personally have no issue with 7# hot at idle in my car. The pressure starts at 50# at start up, kicks down to 30 after choke warms. On the freeway at 3500 rpm, I am at 40 to 50#.

As well, I would have your old oil if you have it still sent to Blackstone labs for an analysis. Blackstone will tell you if your engine is wearing poorly by breaking down contaminants, water, antifreeze, silica, aluminum, copper...etc.

Perhaps the engine wasn't broken in properly or bearing tolerances off. Oil pump bypass valve stuck open..pickup tube off or too close to pan, debris in bypass.

Since you may have no recourse with old builder, why not try a heavier oil with ZDDP? Rotella 15w40? Valvoline VR1 is what I use. I guess my point is this. You know you have a low oil pressure issue for unknown reasons. How much is the tear down and rebuild going to cost assuming new oil pump, bearings, etc. Probably $1200-1600.

I say change the oil out, maybe remove the oil filter housing and clean out the passages while you are there. If it breaks...it was meant to be. Address the issue when it breaks.

Just my .02

I'm hoping I can get whatever is wrong fixed before the whole thing falls apart. I'm going to leave it up to my mechanic as to what to do next.

I also have a fairly fresh rebuild. I have 50-60# at start up. I sat in long traffic one day and noticed the oil pressure close to 0 at idle. I put in a mechanical gauge and it has never been below 15-20# since then. I changed the oil out to 20-50 Valvoline that I had on hand for my boats motors and also added a bottle of ZDDP additive. Not to open a can of worms but your not using a Fram filter are you?

fresh engine no/low pressure... any chance oil pump driveshaft is not hooked to distributer or has a tang snapped off? or rebuilder used a 350 oil pump drive shaft and is not making contact with dizzy. just a thought.

I'll mention all this to my current builder but everything worked fine for about 4 months. I was down to painting the hood tach and now this happens. Also, I only use Amsoil filters.

Also, I went to the Detroit Dream Cruise last Sat and saw a grand total of 2 Firebirds. I did see a 4 door Corvete. I was also looking for a Nash Metropolitan but never saw one. Got back to our car and there was one parked next to us. Small world.

it sounds like the oil pump pick up tube has fallen out of the pump

Some builders tack weld those on just to prevent that.

I think 5 psi is too low.
Pontiac engines have main clearances from 0.0002" to 0.0020".
If a builder or machine shop is not familiar whith Pontiac they will go with the greater clearances of a small block chev or ford.
The machine shop I took my block to machined the mains for a 35 thou clearance even though I told him I wanted 20. I had him redo the mains to get the clearance I wanted. I now have 25 psi at a red light in hot weather and am not worried about a melt down.
Your builder may have machined the main and rod bearings for a larger clearance resulting in low oil pressure, or it may be a failure, lets hope for the former.

You say everything worked fine for four months, If you had good pressure and now low pressure that would indicate a failure somewhere, The mechanic may drain the oil through a paint filter to check if there is any metal in the oil and cut open the oil filter to check for debris. Sounds like a bearing failure. I hope not.

I finally got in touch with the engine builder and he came right over. He checked the original oil filter and found bearing material so now he has the car and is pulling the engine this week. He said it should be done next week. The oil pump pick up was tacked, I was there when that was done. He is wondering if it could be fuel in the engine and there is a slight fuel smell. I guess we find out when it's opened up.

Excellent news. About the builders response that is.

I don't get it.
Never had less then 40 lbs at idle use'n 60 lb pump.

Good that the builder is looking after you.

The pump will move a certain volume of oil depending on the speed of the motor. The pump only builds pressure if there is a restriction to flow. If the pump moved oil through the gears and just dumped it out into the oil pan there would be no pressure. The restriction to flow is mainly the tight clearance between the bearings and the journals. When an engine is new and has tight clearances there is not a large passage for the oil to flow and pressure builds from the restriction to the outflow of the pump. The pressure indicator fitting is in the oil filter adapter where the oil has pressure. As the engine wears the clearances get larger and the restriction is less, pressure drops. Building an engine with larger clearances will give you a larger oil wedge in the bearing journal space and also flow more oil through maybe allowing more heat transfer, but it will have lower oil pressure than a tight clearanced car especially at low to idle rpm. If the flat tappet camshaft gets scrubbed right away that material will be in the oil and wear the main and rod bearings which will result in low oil pressure and eventual engine failure.

That bearing material could be from incorrectly attaching the rods onto the crank with the fillets in the bearings facing towards each other rather than the radius on the journal, or incorrect clearances, or dirt, or a host of reasons, but the cause I've seen the most lately has been flat tappet cams wearing down. My buddies 455 only lasted a week or two until the oil pressure went south, the camshaft material was everywhere in that engine and ruined a crank to boot. That's the reason I went with a roller cam.

I have 25 psi at 500 rpm idle which I'm ok with, I'd rather have the 40 psi that region warrior has but I don't get that until she moves past 1000 rpm.

A lot of engines get built with larger clearances especially high performance and race engines but they spend most of their lives with the pedal matted at high rpms not much time at a red light in 98 degree weather.

I am out of town until next Wednesday and I'm hoping the problem will be diagnosed and fixed by then. For now I just have to wait. I'll post the problem when I get the info.

If you have fuel wash...where the carb dumped raw fuel into the crankcase..that would wash the bearings of oil film and cause metal to metal wear.

My Holley blew a power valve and I didn't know any better..by the time I got to dumping the oil, I had 8 plus quarts of thinner draining out.

Replaced the oil and filter and the engine lasted maybe 2 weeks tops before I lost all oil pressure at 4k on the freeway and seized up the bearings.

>I think 5 psi is too low.<

It’s not a case of thinking. It’s too low, the reason the idiot light came on.

>You say everything worked fine for four months, If you had good pressure and now low pressure that would indicate a failure somewhere<

Now this is a case of thinking.

I love this guy!



Amervo for President!

The latest.... My engine builder took my engine and now won't return my calls. He has had it for almost 2 months. His helper called me and said that he was told the problem was due to fuel dumping into the engine and washing out the oil. I'm not sure I believe this because the carb was running very nice and there was never any smell of gasoline. Also, the fuel filter was taken out and there was no sign of fuel there either. My guess is that something wasn't done right in the engine originally and is now being covered up by saying it was the carb. This total nightmare just won't end.