What causes excessive valve guide wear?
The valve guides experience a lot of wear; because of the constant friction between the guide and valve stem. Side forces on the valve stem, caused by changes in valve train geometry; or by direct acting overhead cams further contribute to guide wear.
What are the symptoms of a bad valve guide?
7 Symptoms of a Bad Valve Guide Seals (and Replacement Cost)
- Lots of Exhaust Smoke.
- Excessive Oil Use.
- Engine Braking.
- Smoke After Idling.
- Cold Engine Test.
- Low Power.
- Ticking Noises from the Engine.
Which of the following problems can be caused by worn valve guides?
The following valve damage and sealing problems can be caused by a worn valve guide:
- Burnt through valve head.
- Breaks in the fillet of the valves.
- Breaks in the grooves for the valve cotters.
- Excessive wear of the valve stem faces.
- Worn rocker arms on one side.
- Increased oil consumption due to worn valve stem seals.
Why do valve guides on cylinder heads wear out?
One thing you can almost always count on when rebuilding a cylinder head is, valve guide wear. The valve guides experience a lot of wear; because of the constant friction between the guide and valve stem.
What should intake and exhaust valve guides be?
Intake valve stem-to guide clearance for most passenger cars ranges from .001 to .003 in. Because, of extra heat, the exhaust, will be .002 to .004 in. Diesel engines as a rule, have looser specs on both intake and exhaust guides than gasoline engines.
Is there anything you can do about a leaking cylinder head?
There is nothing you can do to “fix” the situation without removing the cylinder head (s) and having a complete valve job done. You might get by on the cheap and simply replace the known leaking seals; that would be false economy since the other seals are probably not far from wearing out and also leaking.
What causes oil to go down exhaust guide?
Oil can also be pulled down the exhaust guides, by suction in the exhaust port. The flow of exhaust, past the exhaust guide, creates a venture effect, that can pull oil down the guide. Oil in the exhaust system on late model vehicles with catalytic converters; may cause the converter to overheat and suffer damage.