Spun bearings...under what conditions?

[ghost's_Shadow]

the reason why im opening this thread is because my best friend has a 92 tt stealth and has spuned bearings twice and the funny thing is that always has happened at idle!!! at a stop light.Both times he has replaced the oil pump,he is using Valvoline 10w-40 (very hot weather) and every time he uses mitsubishi oil filter. Is this very common cause i just got myself a 91 tt?

[mikes2nd]

does his oil pan have a dent in it?

[ghost's_Shadow]

nope

[mjannusch]

Moving thread. Not an "Advanced Tech" topic.

[cbatters]

Originally Posted by ghost's_Shadow

the reason why im opening this thread is because my best friend has a 92 tt stealth and has spuned bearings twice and the funny thing is that always has happened at idle!!! at a stop light.Both times he has replaced the oil pump,he is using Valvoline 10w-40 (very hot weather) and every time he uses mitsubishi oil filter. Is this very common cause i just got myself a 91 tt?

If you are concerned about proper lubrication and avoiding a spun bearing, send your oilout for analysis. It will tell you if there are any problems with bearings long before they spin.

You didn;t mention whetehr or not your friend had the crank checked / resurfaced or if he just tossed in new bearings. If there was any damage to the crank, new bearings would not last very long.


Clint

[Quick Vr4]

spun bearings are also mainly caused by detonation.

[cbatters]

Originally Posted by Quick Vr4

spun bearings are also mainly caused by detonation.

100% agree that detonation contributes to spun bearings although I have never seen anything posted to support that it is the most common cause.

Spun bearing causes:

o Detonation
o Low oil level (due to oil consumption on older engines)
o Low pressure/flow (due to worn bearings/pump)
o Incorrect viscocity (lack of film strength)
o Fuel contamination
o Anti-freeze contamination
o Incorrect bearing installation
o Crank / rod alignment
o Improper oil filtration

All of which would show bearing problems in oil analysis long before the bearing actually spins.

Routine maintenance, frequent oil checks and periodic oil testing and you won't be surprised by a spun bearng.


Clint

[ghost's_Shadow]

we he spune the first time he got a new shortblock from mitsu, he installed a new oil pump, and then it happened again at about 6 months later on a traffic jam. rod knockin clak clak clak clak tow truck

[skunkworks]

As clint has said - You have to be very careful with oil level in these cars. Before I replaced my valve steam seals I was using around a 1/2 quart of oil after 400 miles. I had to check my oil every gas fill up. (I still do - it is a good habit to get into.) You have to wait for the gas tank to fill - enough time to check your oil.

Can you imagine if I would not have checked the oil for a few weeks? (I fill up gas every week usually)

sam

[UTRacerX9]

I've spun one. Was cruising around 45 mph, in 3rd or 4th gear. I'd had the car for about... 4 months or so. Previous owner put 10w-30 in it. Since I bought it, with 50k on it, I switched to Mobil 1 15w50.

I recommend thicker oil than a 10w for these cars. Either 15w-50, or 20w-50. Especially in a hot climate. Also, get used to keeping an eye on your oil pressure gauge. Even the stock one, if you see the pressure at a different mark than usual, this is a cause for concern. Cooling is also a big factor (leading to detonation.) Get a downpipe, gut your precats, let your engine breathe easier and cooler. Hot oil is thinner than cold oil.

Also, make sure the oil pan is not dented by the oil pickup tube. Since your friend has spun TWO bearings, he should have made sure the strainer on the tube was not clogged. I've seen that happen before, it's a costly lesson.