Good Day
I just bought this 2005 Bonneville 3800 and the rockers and lifters sound like they aren't getting any oil. Noisy as heck. The engine has clean oil in it and the pressure is great.
I've seen this problem exactly before on 6.0L LS v8's and the oil pick-up O-ring cracks and sucks air. They will still read proper pressure on a gauge but the air bubbles in the oil takes its toll on the lifters and rockers first.
Is this possible also on the 3800 series 2? Also if the pressure valve was stuck partially would I still read oil pressure while starving the top of the engine?

Thanks, Ken

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Chance favors the prepared mind {Louis Pasteur}

Welcome, a few follow up questions;

What information did the seller provide regarding the noise?
How are you checking oil pressure?
what's the odometer?
Maintenance history?

I would suggest first starting with a high quality oil and filter change.

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2004 Bonneville SE 151,xxx- 20% tint all around, 5% tint bar on windshield | 4500k DDM HID low | De-badged | Hardwired Passport 9500ix | FWI(inter-cooler piping) | FE2 Rear Sway Bar | Solid Motor Mount | 180* Stat | Firm Shift Kit



- '92 Bonneville SE - '85 Grand Am - '73 Catalina - '67 Catalina
- '87 Bonneville SE - '82 6000 - '78 Catalina [/color]

The issue I'm familiar with on the LS engines is the pickup o-ring leaking and also reading low oil pressure, especially after a camshaft swap. The 3800 uses a fiber (paper) based gasket on the pickup, the only way it will leak is if someone took the pickup off the motor and didn't replace the gasket.

3800's have a super simple oiling system. Gerotor pump feeds the filter, which flows to the main galley on the 2,4,6 side (cam and mains and 2,4,6 lifters), the rear cover diverts oil to the rear balance shaft bearing and the 1,3,5 galley for the 1,3,5 lifters. If you have a lifter ticking you have an oil pressure issue, no matter what the factory gauge says. Main/cam/rod bearings can live with 10psi/1000rpm (according to most machine shops). From my experience, lifters are never happy with less than 20psi.

The 3800 oil pressure sensor is known for failing and reading 120+ psi or 0 psi. In this situation I would recommend using an aftermarket gauge to confirm what's going on, it's possible the gauge is showing OK oil pressure when it's really low (though low oil pressure in a 3800 usually indicates worn bearings or worse).

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Seller claimed she never heard the noise till I showed up that day. We all know she is full of sheit. I bought it cuz it had clearly been sitting for months and upon a 15 mile road test, by the time we got back the noise had mostly and almost completely vanished. So I bought the car only to find the noise returned by the time I go home. Her father suggested to add something to the oil before driving it home so I don't know what kind of garbage they stuck int the oil. I am not too confident they would be honest if I were to call them back and ask if it were a problem stemming from running it out of oil orit just popped out of nowhere as they claim. OP gauge reads 30 or so then goes up to 45 when reving the engine to 2500. i don't know maintenance history as she only owned it for 9 months and the oil looks clean. Car has 66,000 miles on it and rides like a new car. I got it super cheap and now I know why.

_________________
Chance favors the prepared mind {Louis Pasteur}

Hence my question. When my truck LS motor was sucking air it had plenty of oil pressure but the lifters were clacking away just like my new pontiac. This is why I have been trying to find the exact path of the oil to see if in fact it were likely to be picking up oil before the pump. My ears are so bad I cant be certain if it is bank one, bank 2 or both making noise. I will investigate further and get back to you with a more acute observation. Guage reads 30+ at idle and 45 reving to 2500. 66,000 on the car.
When I repaired my 6.0 LS V8 the ol pick up seal looked good but we al know they can still be leaky. When I called GM to get a seal they suggested I buy a whole pick-up tube assembly as it was only $14. I figure maybe they had been developing cracks in them which are hard to detect. Wonder if the 3.8 pick-up can do the same thing?

Thanks, Ken

_________________
Chance favors the prepared mind {Louis Pasteur}

what does the temp guage read?is it running hot?

remove the oil dip stick while idling - is there oil splashed high on the stick?

how much oi did you fill after draining - it should be a little over 5 litres
close to 6 with filter change

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1992 GTP
1987 Grand Am