You see 3 to 4 bar oil pressure after 5 to 7 seconds of starter speed cranking.

If you just start the engine the oil pressure climbs to this 3 to 4 bar -- I see 4+ bar -- as soon as the engine fires. In less than 2 seconds.

So, why anyone would let the starter develop oil pressure over 5 to 7 seconds vs. let the engine develop oil pressure in under 2 seconds is beyond me.

 

I understand where you're developing your logic Macster, but remember,
much lower bearing pressure with 0hp/tq. made + lower bearing speeds.
Pistons won't be dry dragging when fired, lifters wont be flat, turbo rotating assemblies floating, etc. etc.
Again, good for cars during oil changes and cars that have sat many weeks or months...this isn't for cars that have sat a few days/week, where there is likely still a strong/thick enough oil film to provide momentary fire-up protection.
Cheers,

 

There is sufficient residual oil to ensure lubrication for the brief time it takes for oil to flow at the higher speed the engine obtains shortly after engine start.

Hydrodynamic bearings require speed to develop the oil film that is the bearing. Slow cranking doesn't develop this so the bearing surfaces are more likely to make contact during this slow cranking.

There is a reason why every car maker opts for the same engine behavior at engine start. The engine initially races to a higher than idle engine speed then drops down to its idle speed. This is to develop and sustain the hydrodynamic bearing film until oil reaches the bearings which it does in a very brief period of time because of the higher engine speed.

Slow cranking by the starter just contributes to and exacerbates the very thing you are seeking to avoid.

 

Ouch……… x( ………...

 

we'll have to agree to disagree Macster
I've torn apart and rebuilt engines that have followed this routine...
(along with early oil changes with good oils, and proper warm-ups) one engine(known for day 1), with track use, even after 500,000 km(not a mis-print) the bearings were 'perfect', and re-used...

 

Still waiting for the car.

Will do a complete check of all the hoses and wires first per your recomendation. We'll also drain all the fuel and do a full service.

I didn't plan on warm-up period and another oil change tho. Should I add that to the list?

 

A lot of people leave their car sit over the winter your talking 6 more months not 6years lol. I would change oil add fresh fuel and be on my way= a good full service makes sense if no records are available.

 

Unless you know the car was parked with very fresh oil in the engine schedule an oil/filter service ASAP.


This might be just letting the engine idle long enough to get the engine/oil hot enough to check the level. Once you can check the level the oil is hot enough. Then arrange to drain the oil and replace the filter and add the correct amount of oil to the engine and done.

Unless the engine is not running right you can leave the fuel alone just run it down enough to add fresh premium grade fuel to the tank. However, if the engine runs poorly then the fuel might be too stale.

My sister's new Infiniti sat 6 months and the engine started and ran just fine with the 6 month old premium gasoline in the tank. However, I drove the car enough the fuel level got low and I added fresh premium gasoline and the engine's transformation was remarkable. There was no difference in how the engine started or idled but the engine had noticeably more pep with the fresh fuel in the tank.

A year might be borderline for the fuel though so you'll just have to see.

Or if you want just arrange to have the fuel removed from the tank so you can add fresh fuel. You'll need to discuss this with a tech but you might be able to disconnect the fuel line from the fuel pump at some convenient place and using "shop" power run the fuel pump and let it pump out as much fuel as it can. It will get most fuel out. Then reconnect the fuel line and dump in 5 gallons of fresh premium gasoline.

There is a cost to leaving a car unused for a long time and having to have the stale fuel removed and replaced by fresh fuel might be part of that cost.

I'd budget for a fuel filter change too.

 

why jack around trying to get fuel from the pump area or sucking it out of the tank...thread a hose onto the test port at the fuel filter and run the pump to push all the fuel out there....while you're there get ready to install a new filter for good measure.

 

I can't believe someone would remove the fuse and crank the engine over 5 to 7 or more seconds to "build" oil pressure then install the fuse and then start the engine for real on a regular basis and by enough owners that do this to even reach a rebuild point only to find that the bearings were "perfect" and re-used. Why then were the engines rebuilt?

So I guess we are going to have to agree to disagree.

 

Not a daily or 'regular' basis thing, just any time after extended sitting, which is what this thread is about...
That particular engine was rebuild due to a bent rod on #1, causing piston fracture/break through the wrist pin/ring land area...that engine went on for another 100k km and heavy tracking after rebuild, before it was sold...
Just my real-world experiences... when I build a budget to do rods in my GT2, remind me and I will share pictures of what I tear apart, will review those bearings as well.
Merry Christmas,
Rob