Anybody here have a Hammerhead in a VLX

2007 Wakesetter VLX with a Hammerhead.

I have had oil pressure issues since day one. I am currently running 50W Valvoline. I ran the recommended 15W30 then 40W and now at 50W. Whenever I come down to an idle from pulling a rider, my oil PSI drops to the low teens and sometimes even single digits. No alarm sounds but lately it will sound if it hits 17psi (but not when it goes below).

I know there is plenty of il in the pan but even this is up for debate as I have seen conflicting reports about the oil pan capacity on this motor being anywhere from 4-5.5 quarts.

Last time I pulled the oil out, I made a very conscious effort to get out as much as I could. I added 4 quarts and then checked the dipstick. It immediately read about 1/2 quart over. I can acknowledge that I might miss some when sucking the oil out but but 1-1.5 quarts seem a bit much.

After starting the motor it read perfect on the dipstick which was likely a result of 1/2 quart going into the filter (1/2 qt filter).

Oil pressure was still low at normal temperature when coming down to an idle. Malibu says the oil gets so hot that they can have this issue.

This is also the motor where they sent out the replacement dipstick a few years ago.

Anybody have any insight on this?

First thing I would do is verify the readings you have now by attatching a mechanical guage to the engine and check against current readings.

My good friend had the hammerhead in his 23LSV and it is a motor that tends to burn oil. It is normal. However; you should not be relying strictly on how much oil you replace and refill to verify capacity. Hopefully you have the replaced the dip stick with the newer version; check it on the water prior to start, half way through your day and at the end. Add more on the water if need be. I do remember his oil PSI dropping into the low 20's from time to time and the dealer said it was normal. Keep an eye on your dipstick readings and you should be good to go sir!

Yes I check it in the water and I have the new dipstick in the motor. I don't rely on how much I fill to verify capacity. That's why I mentioned how much I put in compared to the readings and the discrepancy on the oil capacity, dipstick ,etc. The fact is, I don't trust the reading on the dipstick with how much I have put in. However, you cannot add too much oil to the pan because that can cause a bunch of other issues. I don't want to blow a seal (insert joke here).

I had the exact same boat. I sold it 3 weeks ago, so I can't go check for you. I didn't have the same oil burning issues that many have commented about. My pressure seemed to drop a lot when at idle too. It did that when it was brand new. 250 hours later, I had no characteristic changes. It was/is an amazing thing to have that engine in a 21' boat. Especially with the 1235 prop!

The LS1 in my Malibu goes fairly low when idling (say 15-20psi) running 15W40. That said, it runs very high oil pressure at speed (70-80psi). Owner's manual says 4psi minimum hot @ idle, and 18psi minimum hot @ 2000RPM. It's a big of an apples to oranges comparison (Hammerhead is a GEN-1 SBC). But the manual had the same recommendations for pressure for the GEN-1 motors as well.

I'd say as long as your oil pressure is decent at speed, and you have enough oil in, don't worry much about it. In the end, the only real fix would be to pull the motor and replace a bad oil pump at minimum, but probably bad bearings or other BS in the process (which would require a full rebuild). Just run her until she is done...at least GEN-1 SBC's are cheap to rebuild.

thanks nitrous. good stuff.

I think this is very common on the Hammerhead. I had an 07 and had the same issues. I know others have as well. There is a ton of info on it at the Malibu Crew. I replaced the dipstick, which basically just gets you to put more oil in the block and ran 50W as well. I would not get to worried about it, but the guys at the Malibu crew can probably tell you better.