Need help speculating engine problems

[LostOffspring99]

Well, the car took a 4 hour road trip to Nevada and within the last 20 minutes of the drive, the (chain started slapping?) (Oil pump went?) (spun a bearing?).

And when the car is idling the oil light flashes and the knock or slap is REALLY loud. But when its revv'd up it mellows and the oil light turns off.

[FONT=Verdana, Tahoma, Arial, Calibri, Geneva, sans-serif]Needed to drive it back in cali to get towed but the engine seized before crossing state lines. Oil is dirty but it does get its 4 to 5 thousand mile oil changes.

Possibly blocked oil passage? [/FONT]

This is all speculation until the car can make it home. Any other ideas?

 

[BrApple]

So I am a bit confused .... you said the engine locked up, are you speculating that the engine locked up or the reason why it locked up?

The oil pumps are not an issue on these cars so that shouldn't have caused a problem. I have never heard of anyone coming up with blocked oil passages as a problem. The timing chain getting loose would stop the engine from running but it wouldn't cause it to lock up.

If the engine is truly locked up its a spun bearing.

 

[gmorrell]

Spun rod bearings is the main reason these engines go belly up. They are known for having issues with the powdered metal connecting rods, as the engine ages, the big end of the rods go out of round, then a bearing spins, oil pressure starts acting oddly, the engine seizes if you keep driving it. The oil pumps are crank driven and have plenty of capacity, never heard of oil passages being blocked.

 

[cclngthr]

I would say the rod bearing, or main bearing spun. Could be either one, or both. The 2.5 does have bearing issues as it wears, I have tore into several of these engines over the years and have found both bearings going bad; because of wear. Some of it is due to oiling issues, due to leaks or crap in the oil pickup screen. On my engine which has 161,000 and noticed that the oiling was a bit lower than what I expect, which some of it was oil leaks, but after I did a cleanout using kerosene, it brought the pressure back up to normal.

 

[LostOffspring99]

So I am a bit confused .... you said the engine locked up, are you speculating that the engine locked up or the reason why it locked up?

Was speculating on why it locked up. I'm sure it did spin a bearing but why did the bearing spin is the question now. So going by what gmorrell said, the bearings are prone to going bad no matter what?

Also, the engine lost oil pressure just before it started knocking (a few seconds before). Oil was full too. Was going straight up a hill, no sweeping right turns.

Thanks for all the responses. BTW this is engine number 4 for me. The other 3 were spun bearings too but that was cause of carelessness on our part.

 

[BrApple]

IMHO the sweeping right hand turn has no meaning, ie, I have never seen my oil pressure drop on sweeping right hang corners. Now there was a thought a few years ago that using the Taurus 3L oil pan was a potential cause of problems.

Its not the bearings that go bad, its the rods stretching since they are sinter cast. This have been covered in depth in the past. The rod end elongates and the bearing can then slip out of place.

 

[LostOffspring99]

IMHO the sweeping right hand turn has no meaning, ie, I have never seen my oil pressure drop on sweeping right hang corners. Now there was a thought a few years ago that using the Taurus 3L oil pan was a potential cause of problems.

Its not the bearings that go bad, its the rods stretching since they are sinter cast. This have been covered in depth in the past. The rod end elongates and the bearing can then slip out of place.

Oh...didn't know that. Thanks for that info. Didn't mean to bring up something thats been talked about a hundred times before.

So is the solution to get forged rods?

And so I can assume now that a rod elongated causing the oil clearance to change, which caused the oil light to flash, then finally ruining the bearing(s)?

 

[BrApple]

Oh...didn't know that. Thanks for that info. Didn't mean to bring up something thats been talked about a hundred times before.

So is the solution to get forged rods?

And so I can assume now that a rod elongated causing the oil clearance to change, which caused the oil light to flash, then finally ruining the bearing(s)?

Something like that. There should be some good details here and on FCrg if you dig around.

I do believe that forged rods will take care of that issue. although not to many have gone that route. It seems that installing a 3L is normally ok on the stock bottom end. Again some suggested that using a mix of oil pans and pick-up can cause a problem. It has been suggested that since the SVT revs higher and likes being in a higher rpm range that rod bearing failures just happen faster.

And sometime the oil pressure sensor just goes bad and causes the light to turn on.

So it could be any number of things. The lack of oil reasoning could partly be explained by the fact that late model cougars got a 3rd oil return in the head.