Pontiac Bonnivile low oil pressure

Had the local garage put a pressure gauge on it and found about 3 or so pounds pressure at idle and about 15 pounds pressure at 2000 rpm.
Before this happened the pressure was around 40 pounds on car�s gauge (mid scale) when cold and ran slightly under that when warmed up.

I have been told that the oil pump is under the front cover on this engine and a major job to replace. Was going to try a new pump as my first thought was a broken or stuck pressure relief valve. I also found where a few people have said that those engines were known for cam bearings being spun and causing a sudden drop in oil pressure.

Any thoughts on where to look first? Being that old it may not be worth putting too much into it although the body is in excellent shape and has only 60,000 miles on it.

All suggestions appreciated!

Thanks
Gary

Get back to us with what you find. meantime keep driving for a while.

Perhaps a re-man engine would be less costly than replacing the car if the situation is that bad.

My lady friend has a 2001 interpid with 2.7 eng.
Reports are "engines LOCK-UP about 30,000 mi.
We found out WHY? with this one. I think this is a great engine, myself. Did our own OIL ANALYSIS and found red stain from anti-freeze. Turns out that most have a minute water leak because of an internal water pipe leak caused by corriosion of the alloy in the pipe and the new-type RED anti-freeze. Cost to repair..$200.00.
They car now has over 60,000 miles on it with no more "red stain in the oil".

They have several major design issues that when combined are enough to make you wonder what they were smoking when they put it on paper.

The water pump is internal and driven by the timing chain. Dodge cut every corner in the book to design it and it fails way more then average. If (when) it fails it causes the timing chain to slip and their interference valve head design makes the valves hit the piston - the engine is toast in less then a second.

Or the water pump doesn't fail completely, but does weep coolant into the crankcase (remember internal pump). This causes sludge, made worse by the extremely high heat of the upper cylinder heads. The sludge builds up and clogs oil passages in turn destroying the engine. Or the sludge builds up in the front of the engine and the hydraulic timing chain tensioners fail, which causes the valves to strike the piston destroying the engine.

The cheap water pump and its placement is the source of most of these problems but Dodge refuses to acknowledge the issue (despite modifying the design in 2004). Engines with as little as 20K on them have failed but Dodge refuses to warranty them claiming the sludge was the result of not changing the oil. If you change your oil at home you're SOL. Only receipts from a garage that notes the mileage and the services preformed will keep your warranty from being voided.

Dodge recommends that the oil be changed at 6000 mile intervals, and only changing it at 3000 mile intervals in cases of �extreme duty�. But if you have an engine failure as I described above with sludge present your receipts for changing the oil every 6000 miles will resulted in a voided warranty. If you read the fine print all of North America falls in to the category of �extreme duty�.

If one of the passengers wants to, though, they can have a crew member arrested for SMOKMING while in the CAR., Not the airplane, though.

The whole key..... ..... .maintenance and changing parts before their "useful-life" is up as per the manufacturer's recommendations.

I guess that is why..... ...ONLY LEASE, nowadays.
And figger the useful life of a vehicle is when the "ash tray gets full!!!!

I will try removing the oil filter adaptor and check the gasket and pressure relief valve. Maybe I will get lucky� With my luck though it will be more difficult to find.

Thanks
Gary

The oil pressure relief valve is accessable by removing the oil filter mounting adapter assembly at the REAR of the timing cover.

I have seen the gasket between the filter adapter and the timing cover fail, causing a pretty good EXTERNAL leak.

Also, the gasket between the timing cover and the engine commonly fails, leaking externally.

For sure the gasket between the timing cover and the engine could fail towards the INSIDE, dumping oil pressure back into the crankcase. Perhaps the adapter gasket could fail internally, too.

I have HEARD of the cam bearing failure thing, but have never seen it (YET), so I can't comment on that.

The cover really isn't all that hard to remove, except for the fact you're working in a cramped space between the engine and the fender.

Removing the oil filter adapter first will allow you to check that gasket, plus the relief valve and spring.

Oh, yeah, another MISERABLE part of the job is that those gaskets are REALLY stuck to the aluminum parts and block, and are nasty to remove even with the help of gasket removal spray.