Oil Pump....maybe? Tell me what you think.

[Stu]

So last week I'm driving about (97 GTP) when the oil light starts to flicker. It only does it when the car is idling. I was concerned but did not hear any unusual noises coming from the engine, so I decided that when I had the oil changed, they may have put 5W30 in it instead of the necessary 10W30. I went to the shop and they swapped it out no problem. The oil light stopped coming on so I figured that was the issue.

About 30 miles later, the car stalls at an intersection, I start it and this god awful noise starts. The only way I can explain it is like a marble in a blender. It runs enough that I can get it off the road. The oil light was on during this whole time, but there were no other external signs of a problem. No smoke. no engine light, no leaks.....nothing obvious.

So, here is my theory. I know the oil pumps are almost bullet proof in these motors but that is my number 1 suspect. After that, I'm leaning toward it being a rocker arm that's come loose. I have to get it towed in the next day or two and was wondering if anyone has ever had an issue like this.

Thanks for the input,
Stu

[izup69]

Not saying your shop did a ****ty job but did you check the oil level they might of messed up and you could have thrown a rod bearing.

[NegativeOne13]

Just curious.... have you ever done the LIM gaskets?

[MoarkatsINmuhtrailer]

umm yeah rod bearing, or i hate to say it but you may have chunked a piston..buddies 98 firebird (3.8) had the same problem...low oil pressure and number 2 piston was in pieces....whens the last time it had a tune up?

[BillBoost37]

I would say you "spun a bearing" which is a loose term for either excessive bearing wear or a bearing disintegrating. Either of these will cause oil pressure to drop and the noise you hear would be the rod smacking around on the crank.

The light came on because when bearings go, you lose oil pressure. Oil pressure is created by the pump pushing the oil through the crank and rod bearings etc (some cam too) and that's where the actual pressure piece comes in.

Without that pressure and layer of oil, things go bad .

[Stu]

As for the shop I had the oil change done at, they did show me a full dip stick after the change. Everything appeared to be in order. Regarding the LIM gaskets, in the 3 year s I have had the car, I have not had anything like that changed. I have only done the regular maintenance (oil changes, air filters, spark plugs and supercharger oil changes) since I have owned it. For what I paid for it three years ago, I am ready to let it go if it's a big ticket repair.

Is a bearing replacement a major expense on one of these motors? I imagine it definitely would be if a piston is damaged.

[Scottydoggs]

if a bearing let loose a used engine will be your best bet. you could find one for 500 and up, and labor for a swap is upwards of 500, so a easy grand + if thats the case.

[FordMan77]

Time for a used longblock, or entire engine from the sound of things.

Yes, bearing replacement on these engines can be expensive due to you having to align bore the block and machine it straight again or you will be loosing another bearing shortly thereafter. Usually your best bet if you want to try and install new bearings is pay a machine shop to assemble the entire lower end.

[brandonl2000]

I have only done the regular maintenance (oil changes, air filters, spark plugs and supercharger oil changes) since I have owned it

a LIM gasket job on these motors ARE regular maintenance.

and just fyi, a used long block, short of alternator and PS pump, at my local yard is $250. i scored when i spun a bearing in the GT. $250 and it was DONE doing the labor myself.

[BillBoost37]

And...you guys didn't look at his location. A longblock, shortblock ...hell even a scrap metal block is probably over $500 Canadian Pesos.

[FordMan77]

Well, he could always just put some GT rods/pistons in to replace the bad ones, because we all know how well that works

Maybe he knows someone in the states that can hook him up to keep the price down?