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I've noticed on my last trip out , My oil psi was lower then normal so I think Im rite @ 20 psi at idle and 30 psi @ high idle or 4500rpm.
This is my 1st year runing full synthetic oil 10w30 , ? is this the wrong oil should I be runing straight 30 wt or do I have other issue's the engine
is a bone stock 496 ho with 430 hrs any help would be great.
 

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Next time out, I can take pictures of mine at 23-25 at idle in gear. 45-48 at 4000-4500. It's a 2001, but I don't think there were any changes to the oil pressure setups (pumps, springs). I am also 10/30 Mobil1. Maybe your oil cooler is plugged with sand (water side)? I'm at 340 hours with 200 of that on Mobil1. Dunno what to tell ya.

I've noticed on my last trip out , My oil psi was lower then normal so I think Im rite @ 20 psi at idle and 30 psi @ high idle or 4500rpm.
This is my 1st year runing full synthetic oil 10w30 , ? is this the wrong oil should I be runing straight 30 wt or do I have other issue's the engine
is a bone stock 496 ho with 430 hrs any help would be great.
 

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You are getting up there on the hours, I would bump up to the 15w50 it will give you better protection. Your analog gauges are not always accuate, you need to put a scan tool on to check for sure. Remember your engine is working incredibly hard at 4-5k uphill, try that in your tow vehicle for 10 mins and you will think it's going to blow!
 

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Does oil pressure decrease as rpm increases at any time? even a little?
 

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Does oil pressure decrease as rpm increases at any time? even a little?
Pressure should go up to the relief-valve-spring setting. Some people shim the spring with washers to increase pressure. Either way, it will go up to that pressure and start "relieving itself". It should stabilize, but not decrease UNLESS you start out with cold oil and are cruising along while it warms up. When the oil gets thinner, it will drop some pressure.

If you drop SIGNIFICANT pressure, you are either foaming the oil at RPM / OR / the oil is staying in the top end and you are uncovering the oil pump pickup.
 

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You are getting up there on the hours, I would bump up to the 15w50 it will give you better protection. Your analog gauges are not always accuate, you need to put a scan tool on to check for sure. Remember your engine is working incredibly hard at 4-5k uphill, try that in your tow vehicle for 10 mins and you will think it's going to blow!
A water-cooled, oil-cooled pickup/SUV engine will easily run 4000 hours with out needing a rebuild.

This engine works TWICE as hard - let's say - but is still just as stable on temps (has closed cooling AND oil cooler). So, there should be no reason, other than neglect, that a stock roller-cammed coil-per-cylinder distributorless EFI'd motor shouldn't run 2000 hrs without need for hard-parts. Other than maybe valvesprings since these are weakies in the beginning.
 

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I've noticed on my last trip out , My oil psi was lower then normal so I think Im rite @ 20 psi at idle and 30 psi @ high idle or 4500rpm.
This is my 1st year runing full synthetic oil 10w30 , ? is this the wrong oil should I be runing straight 30 wt or do I have other issue's the engine
is a bone stock 496 ho with 430 hrs any help would be great.
The old saying "if you think something is wrong, then something's wrong" applies here. It can be as simple as the gauge sender or as severe as a rod bearing going away. Either way, your oil pressure reading is not right and you need to figure out what changed. A band aid of thicker oil is not the way to fix it. Something changed.... Figure out what the problem is before something serious happens. I would start by removing the oil pressure sender and installing a mechanical gauge. If is back to a "normal" range and increases with rpm, replace the sender with the proper one for the guage range you have and go boating. If it doesn't get better it is something more serious.
 

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The old saying "if you think something is wrong, then something's wrong" applies here. It can be as simple as the gauge sender or as severe as a rod bearing going away. Either way, your oil pressure reading is not right and you need to figure out what changed. A band aid of thicker oil is not the way to fix it. Something changed.... Figure out what the problem is before something serious happens. I would start by removing the oil pressure sender and installing a mechanical gauge. If is back to a "normal" range and increases with rpm, replace the sender with the proper one for the guage range you have and go boating. If it doesn't get better it is something more serious.
I am not suggesting that he put thicker oil in and it will fixx
the problem.
Yes it is important to verify the oil pressure, the 496 is a dual sender engine. The analog sender is being use for the dash gauges, it also has a digital that the computer reads you must hook a scan tool to read this sender. If there is still any ???? you can use a mechanical gauge to verify.

Something change!!! Yes, something change he did not say he heard a rod knock. He said he has a 496 with over 400 hours and he switched to a thinner oil than recommended by the manufacturer and now his oil pressure has dropped.
Is this common practice??
recommended oil 20w/40


Beer30: When or if you ever see 2000hrs on your 496. Beers on me!!!
 

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Thanks everone have heard some good info so far , just some info from my end everthing seems to be running fine at this time I've have not noticed any loss of power and heard any noises at this time , i'm just worried about the pressure it may be just a guage or a bad sender i'm hoping but you dont know my luck , and more info would be great /
Thanks
 

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Beer30: When or if you ever see 2000hrs on your 496. Beers on me!!!
Exactly! Do you realize how LONG it would take to get 2000hrs on one?? With a high season being 100hrs - you do the math.
 

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Exactly! Do you realize how LONG it would take to get 2000hrs on one?? With a high season being 100hrs - you do the math.
The offer still stands !! Have fun, be safe, It's all good.

Here's some math: Over 2500 post, less time at the computer = more time on the water!!
 

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I am not suggesting that he put thicker oil in and it will fixx
the problem.
Yes it is important to verify the oil pressure, the 496 is a dual sender engine. The analog sender is being use for the dash gauges, it also has a digital that the computer reads you must hook a scan tool to read this sender. If there is still any ???? you can use a mechanical gauge to verify.

Something change!!! Yes, something change he did not say he heard a rod knock. He said he has a 496 with over 400 hours and he switched to a thinner oil than recommended by the manufacturer and now his oil pressure has dropped.
Is this common practice??
recommended oil 20w/40
My post was not meant to offend you, i'm sorry if it did. :) As a Certified Premier Mercruiser Dealership I am aware of the sensors and their functions. I was only offering a way to the original poster as to how he could verify if he had a problem or not on his own. Also I was hoping he wouldn't just change oil in hopes of it fixing his problem. Although 10/30 synthetic is not what I would recommend, it still should be higher than 30 at 4500. That raises a red flag.

I will join you and Beer30 when any 496 in a boat reaches 2000 hours... and still runs! :wink2:
 

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I will join you and Beer30 when any 496 in a boat reaches 2000 hours... and still runs! :wink2:
Your proof as to why one won't?
 

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So if 10/30 synthetic isn't would some would recommend what do you suggest I run. ?

Thanks
Just try something thicker and see where the pressure ends up. Try some straight-40 and see what the difference is. Just be careful of cold-starts. It will take a few more seconds to get that through the veins.

I agree that 30psi at 4000+ is too low. Could also be the gauge, though. I just fired mine a few days ago. Let it warm up for 30 minutes and at 4000 it was just a needle-width below 45. 10/30 Mobil1.

You either have a bad gauge, sender, or - again - maybe your engine oil cooler has some sand blocking the inner passages?
 

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A water-cooled, oil-cooled pickup/SUV engine will easily run 4000 hours with out needing a rebuild.

This engine works TWICE as hard - let's say - but is still just as stable on temps (has closed cooling AND oil cooler). So, there should be no reason, other than neglect, that a stock roller-cammed coil-per-cylinder distributorless EFI'd motor shouldn't run 2000 hrs without need for hard-parts. Other than maybe valvesprings since these are weakies in the beginning.
2,000 hrs I would love to see that, So would Mercruiser...
 

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2,000 hrs I would love to see that, So would Mercruiser...
Where's the proof otherwise?

Nobody ever leaves one in that long - more power and speed usually warrant an engine build.

Throttle will probably be the closest ever. He probably has 800hrs on his so far.
 

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Where's the proof otherwise?

Nobody ever leaves one in that long - more power and speed usually warrant an engine build.

Throttle will probably be the closest ever. He probably has 800hrs on his so far.
what i;ve seen is the 500 hp , 502 are done at about 600 hrs, at least the lifters, rockers, springs need replacing. valve guides, so 2000 is a little tough to get to. but your right about everybody wants to go faster and that usually warrants an engine change or build.
 

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I've noticed on my last trip out , My oil psi was lower then normal so I think Im rite @ 20 psi at idle and 30 psi @ high idle or 4500rpm.
This is my 1st year runing full synthetic oil 10w30 , ? is this the wrong oil should I be runing straight 30 wt or do I have other issue's the engine
is a bone stock 496 ho with 430 hrs any help would be great.
I was told not to run Fram oil filters. I used a Fram Racing filter thinking it would be ok. It collapsed on my first trip out. Almost cost me a $15,000 motor. Fram filters are crap....
 
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