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Spun a bearing

G

GTP4

New member
Hey everyone, the local club has had a series of members that spung bearings most recently,i for one. Puzzled we are. What are the main reasons that cause a motor to spin a bearing?
Simply put, we'd like to see what causes a spung bearing, either due b/c of coolant leakage, an aged engine?, maybe a tune gone wrong?
My mech said one of the bearings spuned to the next cylinder.
He says main reason is wear and tear.
 


I have an 02 motor on the car now,only the short block.
And i'm trying to prevent another similar problem.
 
Its really hard to say. There are a few reasons, coolant contamination among them, for a spun bearing. You can wear the bearings out I suppose, but I have not seen much of that. It is by far more common to spin a bearing from coolant contamination.

The only REAL way to know for sure is to do an oil analysis. That will tell you if there was coolant in the oil, excess lead that would come from bearing wear or other such metal contaminants that would point to excessive wear somewhere. Depending on what metal showed up would determine the cause.
 
Do you guys use synthetic oil? My motor is over 10 years old, gone thru various LIM gasket changes (one in which I put RTV on and ****ed up which resulted in coolant in my oil, a cam change, various track passes, a wreck, etc. And its still running strong. But I change my oil religously, almost every 2 month damn near.
 


This time around, im using nothing but syntetic oil.
They say, it has a better protection against coolent on oil.
 
It does to a small extent, but dont let that make you complacent, coolant in the oil is still coolant in the oil and needs to be addressed. It would also depend on the extent of the leak and how much its dumping into the oil.
 
what is all of your reasoning for suggesting using synthetic oil? i use whatever 10-30 is cheapest at the time and my car runs just as strong as any.
 


1. Reduced friction, translates to less heat and better fuel economy.

2. Reduce wear, translates to longer equipment life.

3. Better quality product if it is a true synthetic, translates to being able to go longer between oil changes which saves on maintenance costs.

4. Better environmentally. If you use longer oil change intervals, particularly if you are changing your oil every 3000 miles, and say go to a 5000 or 7500 mile oil change interval you are reducing waste materials like the oil containers, oil filters and such ending up in our landfills.

There are other good reasons too. Since I learned of oil analysis testing, I do not change my oil or filters until the analysis testing says it is time to do so. Which, typically I go way beyond even the generally accepted 7500 mile oil change interval.
 
Lol it cost me 30 bucks to use mobile 1 sythetic. If you can't see the advantage of using it over dino to save 15 bucks or so then that's sad IMO. Sometimes we are TOO cheap.
 
I only have to change my oil twice a year at most with synthetic. Compared to what I'd be doing in dino oil based off time intervals I'm saving money.
 


I'll give you a quick example of the savings synthetics offer. I have a diesel customer that I am good friends with. He has a commercial floor cleaning business and drives a Dodge 3500 with a 5.9L turbo diesel. He came to me and asked if I could help him out. With the amount of driving he was doing he was having to change his oil every 3 - 4 weeks. It was costing him around $45 to do it as well using regular non-synthetic motor oil so it was costing him near $550 a year plus the down time to get it done.

So I did a work up for him and using the best synthetic motor oil that Amsoil had at the time and an oil filter. That ended up costing around $150 for the oil and filter. We did an oil analysis on the oil at every scheduled filter change.

To make a long story short, he ended up getting over 60,000 miles out of that oil change before he decided to go ahead and change it on his own even though the oil analysis said he could go further. Between the oil filters and oil analysis he may have spent around $225 maybe $250.

So ultimately he was able to save about 50% on his maintenance costs and its even more now because we dont do an oil analysis as often. We did them more frequently to start so that we could establish a baseline for how long his oil drain intervals could be. That doesnt take into account the savings in time having to get in for an oil change about every month. He also picked up a couple miles per gallon in fuel economy too and with as much driving as he does, that translates into even bigger savings.

My Grand Prix alone I went over 15k miles on one oil change before the oil analysis showed I had a coolant leak from the LIM gaskets. Even then the oil analysis showed no significant increase in wear in the rod bearings or engine wear so I could have went even further, but I shorted my change intervals to 7500 miles until I got the LIM gaskets replaced. I pulled an oil analysis at those intervals and those too showed that I could have gone further but not knowing if the leak would get worse over time I chose to stay with the shorter change intervals.

Additionally, when I first got the Grand Prix I got 28mpg on a trip to Florida the week I bought the GP. I got back home and switched the transmission and engine over to synthetics. About a month after getting back I had to make an emergency trip back to Florida and I got 31.5mpg the whole trip.

I was in the 33 mpg range, all highway, when the differential went out on the GP. So if you take advantage of what a good, true synthetic motor oil has to offer, they can ultimately save you money in more ways than one.
 
A spun bearing is exactly what it sounds like. Something has broken down somewhere along the way, and the crank basically rubbed the bearing, causing it to shift in the journal. Sometimes it's so bad that they actually overlap each other, but that's an over the top severe case. Whether it's from coolant in the oil, or a drop in oil pressure, over revving the engine that the oil pump can't keep up etc....it's hard to say what actually causes it in most cases. You'd be surprised at how much oil is not in the pan after you run it hard for more than 15 seconds or so. Most of it ends up in the top of the engine, or actually "roping" around the crankshaft.

If you're gonna race your car hard, then you really don't wanna skimp out on good oil.......period.
 
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