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Blow-by is an indication of worn rings. While the PCV valve can take up SOME of the blowby gasses, it can't take care of a lot, especially if you have severe blow-by. If you're still getting too much blow-by, it's time to rebuild the engine. Don't just do rings, have the cylinders bored and get new pistons, and while it's apart, replace the oil pump, have the Camshaft checked, replace lifters, polish and/or turn the crank, new bearings, new exhaust valves, replace or recondition all valve guides, and have the head surfaced. It's not very cost effective to just replace the part that has failed. Everything in the engine has worn severely over time, and you'll actually save in the long run if you do the engine right. BTW, don't ever let an engine overheat, that can lead to collapsed rings. Also, keep the oil and filter clean, and make sure the carburater is adjusted and working right and that the air cleaner is doing its job and is clean. Dust in the engine intake can cause rings to wear, resulting in blowby. In general, just make sure the NEXT engine is properly maintained and you shouldn't have blow-by problems.

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โˆ™ 2006-09-13 14:30:16
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Q: 1986 Ford Bronco w a 351W why do you keep getting blow-by even after changing the PCV and doing a complete tune-up?
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How do you fix engine blowby?

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Blowby is caused mainly by?

Combustion pressure getting past the piston into the crankcase. Worn rings or failed piston are normal causes.

Can blow by be caused by a faulty turbo?

not really. You can get blowby in the turbo itself from high crankcase pressure, but a turbo won't cause engine blowby.

What is wrong if the place you put oil is smoking?

you are a couplke of years late in changing it regularly. It's called "blowby". When the piston rings wear down, combustion gasses leak between the piston and cylinder into the crankcase. Blowby is arguably one of the best indicators of engine maintenance. Old oil picks up small pieces of abrasive materials that wear down the cylinder walls over time.

Theoretical of blow-by in engine?

Some blowby is normal in all engines, this is the reason for the pcv system (positive crankcase ventilation). excessive blow by, is the cause of worn pistons and or piston rings. excessive blowby will alot of times show up in the air cleaner box as raw oil that the pcv system just could not handle. If indeed you do have excessive blowby it is a major internal engine failure. Again blowby is normal in all engines, but it should never be so excessive as to show smoke in the blow by

What is blowby in an Internal Combustion engine and what can happen if it increases above normal level?

Blowby is the result of the piston rings not sealing properly against the cylinder walls any more allowing exhaust gasses to enter the crank case. This results in reduced compression which translates into reduced performance and fuel economy. It also results in more frequent oil changes as it leads to increased oil contamination. Left unchecked it can further reduce overall engine life due to contamination of the oil. Repairing an engine with excessive blowby will generally require a complete rebuild along with machine work on the engine block.

Ford 300 motor has lots of blow by?

blowby is caused by broken and worn piston rings

How do you fix engine blowby coming from the valve covers on a Chevy 350?

The problem could be valve seals or excessive piston ring blowby. You could try changing the pcv valve on the valve cover and check the line going to the intake plate to make sure its not stopped up or the intake plate isn't stopped up. However, it most likely means that the piston rings are worn out are broken. Time for a engine rebuild. That is the only way to fix that problem.

Why is there white smoke coming from the dipstick tube and the valve cover on a 89 ford F150 4.9L?

excessive blowby

What is compression blow by?

Compression blowby is air, fuel, and exhaust gasses slipping past the piston rings into the crankcase.

What would cause oil filter cap to pop off while driving?

blocked pcv or excessive piston blowby..

Oil in the air filter on a 318 motor?

you are getting blowby from a bad pcv valve. this is in the hose that runs to your air cleaner. there is also a sponge or fiber filter there that probably needs changed too. worst case is your valve seals are shot and need replaced.

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