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jfergvt

Change in oil pressure after oil change on '87 skier?

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jfergvt

Hi,

I'm wondering if anyone could give some info about oil pressures? I have a Commander Marine 351 in my '87 skier. I bought the boat last year with fresh oil already in it. I just changed the oil this weekend and put in 25W40 on the advice of a boat mechanic. I also replaced the filter with a teleflex that was comparable to the Quicksilver that was on there. After I changed it I found a PCM manual (closest to my Commander?) and it said to use 10W40. I took the boat out yetserday hoping ot ski one last time this year. At startup I was getting pressure of 40-50psi. When I throttled up I was getting 75psi heading toward 80. I have never seen pressures like these all season so I immediatley throttled down and brought her in. I did check the oil when warm sitting in the water and it registered 1/2 quart low even though I out 5 quarts fresh in.

Does this sound normal or am I seeing signs of an issue?

Thanks,

Jeff

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zone 5

That pressure is higher than I've seen, but its unlikely you have an issue. Offshore, we see these numbers all the time, and as the oil heats up, it drops back down. The 2nd number in oil weigh is the one that really matters in boats.(under warm/hot conditions) The 1st number is how it acts in cold weather when we don't usually run them. So you have 40w prior and current oil no matter what the 1st number is (in really simple terms).

I have never heard of a teleflex oil filter before. I suppose its possible that you have an issue with the filter and it doesn't have a bypass valve, or its not working right.

You might want to pull that filter and get an other thats made for the 351. I would not recomend using it for ever, but to see what happens just go to walmart and get the Fram that is listed for your motor.

"assuming" that you have the correct dip stick, then if its low, its low. I'm not sure what a 351 takes, but it could very well hold more than 5 quarts with the filter change.

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srab

Those oil pressures sound perfectly normal to me.

Don't know about an '87, but most of the newer boats run 15W40 Marine or Heavy Duty Diesel oil.

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Nitrousbird

Please don't put a Fram filter on that motor. Ever.

I wouldn't be all that concerned with the higher pressure. I see 70psi under heavy load all the time. Wouldn't be a bad idea to swap to another quality oil filter (again, NOT A FRAM).

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zone 5

Please don't put a Fram filter on that motor. Ever.

I wouldn't be all that concerned with the higher pressure. I see 70psi under heavy load all the time. Wouldn't be a bad idea to swap to another quality oil filter (again, NOT A FRAM).

Note my use of the words "not recomend" in the sentence. I know everyone hates Fram, but for a 15 minute test, its a cheap way to see if anything changes.

As I said, I don't see an issue with the number, but if it has increased by a large amount, it may be something to look at.

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martinarcher

They don't call them the "Orange Can of Death" for no reason. :lol:

I do agree.....it would be fine for a short term pressure check but I wouldn't ever install one on my engines. I highly doubt the pressure is due to the filter.

I'm not familiar with the 351's as much as the 350 Mercs, but I run 10W-30 synthetic in my boat and see pressures underway around 50psi after warmed up. It will run higher for the first 15 minutes as the oil warms since it is a bit less viscous until it reaches operating temps.

Any idea what pressures you were seeing before? Do you know what weight oil was in it form the previous owner? My guess is he was using a thinner oil that you have put in it.

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jfergvt

Thanks for all the response.

Previously I was around 60 psi under load warm. The numbers I was getting were warm also. The Teleflex filter was branded as Sierra. I got it at West Marine. The oil I did use was Mercruiser Brand Oil. I will definitely try another filter. I have no idea what type of oil was in it when I got it. I bought it used at a dealer and they told me "it had been gone through" including oil change. Is there any chance of clogging an oil pick up or anything when shoving the tube down the dipstick hole to pump the old oil out? In terms of the pressures My stock gauge only goes to 80 so when I saw it getting near that number I got spooked. The PCM manual I have for a 351 engine says 35-40 psi at 200 RPM.

What number would be too high and what damage may ensue from such a number?

Thanks,

Jeff

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happypappy

Thanks for all the response.

Previously I was around 60 psi under load warm. The numbers I was getting were warm also. The Teleflex filter was branded as Sierra. I got it at West Marine. The oil I did use was Mercruiser Brand Oil. I will definitely try another filter. I have no idea what type of oil was in it when I got it. I bought it used at a dealer and they told me "it had been gone through" including oil change. Is there any chance of clogging an oil pick up or anything when shoving the tube down the dipstick hole to pump the old oil out? In terms of the pressures My stock gauge only goes to 80 so when I saw it getting near that number I got spooked. The PCM manual I have for a 351 engine says 35-40 psi at 200 RPM.

What number would be too high and what damage may ensue from such a number?

Thanks,

Jeff

Couple of things to consider:

Just how warmed up was the engine?

your temp guage is water temp, not oil temp...oil temp takes a tad longer to bring up to operating temp. After fully warm, check to see of the oil pressure is with the normal operating range

check to see the right oil was used.

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jfergvt

Couple of things to consider:

Just how warmed up was the engine?

your temp guage is water temp, not oil temp...oil temp takes a tad longer to bring up to operating temp. After fully warm, check to see of the oil pressure is with the normal operating range

check to see the right oil was used.

Hi,

I just warm the boat up in the driveway for a good 15'. My cold startup number was 55-60 psi. After warming up I ran it up to 2000 RPM and got 60-65 PSI. THere was a fair amount of bouncing on the gauge. So If the gauge is good I'm running approx 15-20 psi above the manual and my previous numbers.

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zone 5

Thanks for all the response.

Previously I was around 60 psi under load warm. The numbers I was getting were warm also. The Teleflex filter was branded as Sierra. I got it at West Marine. The oil I did use was Mercruiser Brand Oil. I will definitely try another filter. I have no idea what type of oil was in it when I got it. I bought it used at a dealer and they told me "it had been gone through" including oil change. Is there any chance of clogging an oil pick up or anything when shoving the tube down the dipstick hole to pump the old oil out? In terms of the pressures My stock gauge only goes to 80 so when I saw it getting near that number I got spooked. The PCM manual I have for a 351 engine says 35-40 psi at 200 RPM.

What number would be too high and what damage may ensue from such a number?

Thanks,

Jeff

Sierra filter needs to go. I have no idea who makes it, but everything I have ever used that says Sierra on it is lower quality than the name brand. There are multiple threads on here about which oil filters to you. Wix and K&N are good choices.

Your oil choice is fine.

Pushing the tube in to suck the oil out caused you no problems.

The PCM book is giving you a range, on the low side to cover them. 60 lbs is common.

High oil presssure does nothing except take horsepower away because the pump is using HP to make that pressure. in the racing world that matters, in our world, it doesn't. I would only worry if the gauge was staying at 80 all the time. Then it could be a blocked bypass, or just a bad gauge. As long as it drops as you run the boat, its fine. You need to run it on the water. On the hose is not getting it as hot as pulling will.

If your gauge is bouncing around, it means its like most electric gauges, and its not reading very well. Not a real big deal.

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jfergvt

Sierra filter needs to go. I have no idea who makes it, but everything I have ever used that says Sierra on it is lower quality than the name brand. There are multiple threads on here about which oil filters to you. Wix and K&N are good choices.

Your oil choice is fine.

Pushing the tube in to suck the oil out caused you no problems.

The PCM book is giving you a range, on the low side to cover them. 60 lbs is common.

High oil presssure does nothing except take horsepower away because the pump is using HP to make that pressure. in the racing world that matters, in our world, it doesn't. I would only worry if the gauge was staying at 80 all the time. Then it could be a blocked bypass, or just a bad gauge. As long as it drops as you run the boat, its fine. You need to run it on the water. On the hose is not getting it as hot as pulling will.

If your gauge is bouncing around, it means its like most electric gauges, and its not reading very well. Not a real big deal.

Nuff said,

Thanks for the help.

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happypappy

You can get yourself a mechanical oil pressure guage and install that to verify exactly what oil pressure you are getting....That is the best and most accurate, if you have concerns.

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