Wrist pin noise in a 248?

[GMorse]

Good afternoon, Just wondering if any of you folks with a 248 engine have ever heard a noise that sounds much like loose valves, but actually turned out to be worn wrist pins? I have found people on Google who have had this problem, but none on a Buick 248. I may have a problem in this area, and I would like to hear from anyone who had this problem, and it for sure turned out to be worn wrist pins.
Thanks for any info.
Gary

[gishmonster]

HI
I had a neighbor who was always working on junk cars. He had an old 80s Buick he was working on and asked what I thought about the engine noise. It was rattling bad with what sounded like a rod more than a wrist pin. He tore the head off and found a machine small screw that had a round head sitting sideways and stuck to the top of the piston. He knocked it off and the car ran great.

So it is really hard to tell what the noise is without tearing something apart.

Good luck

gishmonster

[CNC-Dude]

You can pull plug wires off of the engine one at a time while its running to help narrow down which cylinder it likely is. Worn wrist pins can happen in any engine, but usually on high mileage ones or ones that have been abused and run low on oil or with low oil pressure.

[LONG]

does a 148 have hyd lifters? could it be valve train noise? lash or hyd lifter leaking down? is it all the time or hot/ cold?

[GMorse]

Thanks for the suggestions from everyone. The short reply is that does not have hydraulic lifters, and the noise is coming from more that one cylinder, making it hard to pin down. It sounds just like excessive valve noise, but only above
1200 RPM, and only when you put a load on the engine, say you are moving at 40 mph, and accelerate to 45 mph,
when the engine is under load to raise the speed, the noise starts - and will go away as soon as you back off the accelerator.
This noise is not very loud, but certainly noticeable Some people would just ignore it, but I will keep looking.
Thanks
Gary

[firstofeight]

Sounds to me like you need to drop the pan and check bearings.If I understand your explanations, that is what it sounds like it may be.

What is this engine in?

Ben

[GMorse]

Thanks for the reply. Ben, this 248 is in a '39 model 48 which I have owned for 14 years.
Gary

[Jenz38]

For me too its sounds like the rodbearings, if you have droped the pan ,pull the bearing inserts and only they are worn,.nothing to see on the Crank journals, then i only would make the bearings new in the same size.
Whats now your oil pressure ? If its falling down while engine is warm,its a sign for pressure lost thru the bearings.

[TexasJohn55]

Gary,
Just for grins, back off the timing 5 or so degrees and recheck just to be sure it is not detonation, Not likely but easy to check. Does it make any noticeable noise when revved up out of gear? John

[Jenz38]

Gary, some news ?