Oil Analysis for high-hour 4.5L 250 HP

[TomB985]

Good morning, everyone.

I recently upgraded to a 2019 Monterey that I bought at an auction last spring. It was a fleet boat for a local boat club, so it had 1,100 hours on the clock at the start of the season. The club mechanics told me they changed the oil every 100 hours and use OEM parts, but I was always a bit concerned about how many hours it had.

I probably run this engine harder than most of its previous operators, so I was pleasantly surprised to see a good-looking oil report. I wanted to share it here in case any of you find it interesting.

 

[Lou C]

Very good report in terms of wear metals but they didn't really explain why the oil viscosity was lower than it should be. Looks to be a high 30 wt viscosity instead of 40. I have used the Mercruiser/Quicksilver oil and done the same analysis with Blackstone and I have not seen it fall out of range for the specified viscosity. You can use the more expensive Syn Blend 25/50, not sure if that would hold up better, it is very expensive ($52 a gallon).

 

[ROY WILLIAMS]

Good morning, everyone.

I recently upgraded to a 2019 Monterey that I bought at an auction last spring. It was a fleet boat for a local boat club, so it had 1,100 hours on the clock at the start of the season. The club mechanics told me they changed the oil every 100 hours and use OEM parts, but I was always a bit concerned about how many hours it had.

I probably run this engine harder than most of its previous operators, so I was pleasantly surprised to see a good-looking oil report. I wanted to share it here in case any of you find it interesting.

Molybdenum is also utilized in various industrial applications. One of its significant uses is in engine lubrication, where it is added as a lubricant additive to enhance the performance of lubricants. Molybdenum compounds have excellent anti-wear properties and can reduce friction and protect engine components from wear under extreme pressure conditions and metal-to-metal contact. This helps in the formation of a durable lubricant film, ensuring smooth engine operation and improved efficiency ....
the oil 400 ppm SPEC . MOLYBDENMUM additive ..
I was the 4runner TOYOTA ENGINE OIL 700-800 PPM ZINC/MOLY/PHOS ....

 

[paulswagelock]

I have seen several analysis now on the Merc oil where it sheers to a 30 wt. still functioned well, but it does not hold its grade well.

 

[ROY WILLIAMS]

I have seen several analysis now on the Merc oil where it sheers to a 30 wt. still functioned well, but it does not hold its grade well.

the new engines oil 25-40wt ... years ago 30w 32-90 F ,,,, 40W 90F higher air temps ..
I did the 30w oil engine MCM470 year 1978 MOLY 400PPM/ZINC 700 PPM / PHOS 750 PPM ..AIR TEMP 90F BELOW .... I was the FLAT TAPPETS additive zinc plus 4 oz. ..

 

[Scott06]

I have seen several analysis now on the Merc oil where it sheers to a 30 wt. still functioned well, but it does not hold its grade well.

I never had an analysis but found with merc 25W-40 when used at higher rpms for extended time my oil pressure would drop from around 60 to low to mid 40 s . Not sure if it was shear or foaming or what. Also had similar with rotella 15/40. found Mobil one 15w50 did not do that

 

[Lou C]

What would be very interesting to see would be oil analyses done with the Merc oil vs other popular choices
Merc 25/40 mineral
Merc 25/40 syn blend
Merc 25/50 syn blend (tried this to see how it compares to 25/40 mineral which I’ve used for 10+ years).
15/40 Rotella or 15/40 Delo
Straight 30 or 40

 

[paulswagelock]

What would be very interesting to see would be oil analyses done with the Merc oil vs other popular choices
Merc 25/40 mineral
Merc 25/40 syn blend
Merc 25/50 syn blend (tried this to see how it compares to 25/40 mineral which I’ve used for 10+ years).
15/40 Rotella or 15/40 Delo
Straight 30 or 40

I did a similar evaluation years ago, so the formulations have changed. The Merc branded oils all sheared to a 30 or 20 wt but the wear metals were still ok. Rotella 15w40 held grade and the wear metals were good, even a touch better but it was only 1 analysis. Valvoline 15w40 held grade and wear metals were again a touch better. Mobil1 15w50 sheered some, but the metals were fine.
All of these were on a 350 mag, so a motor easy on oil. My experiment was more to prove Merc oil was not special and costly compared to other alternatives.

 

[Scott06]

My experiment was more to prove Merc oil was not special and costly compared to other alternatives.

exactly the conclusion I came to. I normally am a OEM user but M1 seems to be a better oil.

 

[Lou C]

Interesting
I have done 3 oil analyses with the Merc 25/40 conventional oil and every time it was still in grade for a 40 wt. This year I tried their Syn Blend 25/50 and am waiting on a sample I sent in this week. This is Merc’s best oil for racing sterndrives & Verado outboards. Will report back when I get the results from Blackstone.

 

[paulswagelock]

Interesting
I have done 3 oil analyses with the Merc 25/40 conventional oil and every time it was still in grade for a 40 wt. This year I tried their Syn Blend 25/50 and am waiting on a sample I sent in this week. This is Merc’s best oil for racing sterndrives & Verado outboards. Will report back when I get the results from Blackstone.

I would like to see that one.

 

[Lou C]

Probably will take a couple weeks. BTW I have oil analyses on this same engine dating back to 2011.

 

[Lou C]

Here's the one up to last year.
The high levels of sodium and high wear were the beginnings of leaking head gaskets (boat is 100% used in salt water). Got water in a cyl at the end of '16 season, replaced heads with reman units over the winter of 2016/2017 (took old ones to a machine shop, found both cracked from an overheat in 2013). Used Fel Pro Marine head gaskets which I think are probably better than what the OEM was. Replaced all the cyl head bolts too. Probably should have fixed it sooner, but live and learn. So far I am still high on iron, but it dropped from the first report after fixing it. The bottom end is original, from 1988. Used in the salt at least 20 years not sure about previous owners.
For the report done in 2011 I was using Chevron Delo straight 40. Started using the Merc oil the next year. So the 3 later reports are all with the Merc 25/40 conventional. We will see if the syn blend 25/50 makes any difference.
I also thought of trying the Valvoline VR-1 20/50. A good oil high in zinc, a lot cheaper than the Merc/Quicksilver 25/50.

 

[Pmt133]

I'd post my analysis from my 4.3 but it'll be skewed because that was on a fresh rebuild. I'd say it is comparable and will post if anyone is interested and wants to cross compare. I pretty much always run delvac 15w40... good results on my old 3.0l and on the diesels in the 33. When it can be had for ~9$ a gallon you really can't go wrong. I've also run 20w50 and merc in the past. I change it so frequently it doesn't really matter all that much. I also run it in the 55 and the 67... I use mobil 1 in the vette.

 

[ROY WILLIAMS]

Here's the one up to last year.
The high levels of sodium and high wear were the beginnings of leaking head gaskets (boat is 100% used in salt water). Got water in a cyl at the end of '16 season, replaced heads with reman units over the winter of 2016/2017 (took old ones to a machine shop, found both cracked from an overheat in 2013). Used Fel Pro Marine head gaskets which I think are probably better than what the OEM was. Replaced all the cyl head bolts too. Probably should have fixed it sooner, but live and learn. So far I am still high on iron, but it dropped from the first report after fixing it. The bottom end is original, from 1988. Used in the salt at least 20 years not sure about previous owners.
For the report done in 2011 I was using Chevron Delo straight 40. Started using the Merc oil the next year. So the 3 later reports are all with the Merc 25/40 conventional. We will see if the syn blend 25/50 makes any difference.
I also thought of trying the Valvoline VR-1 20/50. A good oil high in zinc, a lot cheaper than the Merc/Quicksilver 25/50.

THE ENGINE OIL SPEC IRON 80 PPM HIGHER LOU C ENGINE ..

 

[TomB985]

I gave up on oil wonkery about ten years ago, but I still check in to BITOG every once in awhile. I don't know exactly which Merc 25w40 this was because the previous owner wasn't that specific.

The 4.5L is a relatively new engine, and mine probably has more hours than 99% of them because of its constant use as a club boat. I got the boat about $14K under book at auction, and my big purpose was to see how well this well-worn 4.5L engine was holding up. Looks like my auction gamble is paying off based on this UOA.

 

[Pmt133]

You know, I never really dug that deep into it but aren't the 4.5/6.2 just in-house tweaked versions of the 4.3/5.7 since GM no longer produces them?

 

[Scott06]

You know, I never really dug that deep into it but aren't the 4.5/6.2 just in-house tweaked versions of the 4.3/5.7 since GM no longer produces them?

No they are Merc produced engines not GM based. the 4.5 bears no resemblance other than number of cylinders to the 4.3..

It is confusing on the 6.2, Merc did use a GM bases 6.2 up until like 2015 ( stroked 5.7) the new Merc 6.2 other than displacement has no commonality with GM made engines.

I think where this will hurt guys like us is if you ever need an engine you can only get it through quicksilver/merc. Not sure if the aftermarket will start supplying machine shops with rebuild components but the days of getting a relatively off the shelf GM marine new base engine or reman are likely over.

 

[Pmt133]

No they are Merc produced engines not GM based. the 4.5 bears no resemblance other than number of cylinders to the 4.3..

It is confusing on the 6.2, Merc did use a GM bases 6.2 up until like 2015 ( stroked 5.7) the new Merc 6.2 other than displacement has no commonality with GM made engines.

I think where this will hurt guys like us is if you ever need an engine you can only get it through quicksilver/merc. Not sure if the aftermarket will start supplying machine shops with rebuild components but the days of getting a relatively off the shelf GM marine new base engine or reman are likely over.

Thanks for the info. I'll probably never own something that new and I've actually never seen a 4.5 up close though saw a 6.2 and while different for sure... It seemed derived or maybe inspired from a small block but I was on the fence about it. It looked "odd" for sure.

The whole merc only thing sucks but that sadly is the way everything has been going basically since I was born. Everyone wants control start to finish.

 

[Scott Danforth]

look at the rotating assemblies...... racing buddy of mine has a 2016 merc 6.2 with a damaged block..... the rotating assembly looks a lot like the GM SBC 377/383 rotating assembly. Not sure on the 4.5. I suspect the same bore/rod combination, just a slightly different stroke.