valve guide seal

mack2610 · 09-15-2009, 03:02 PM

1990 chevy c1500 4.3: i think i have bad valve guide seals # 4 cyl but i'm not quite sure. how can i be 100%? here are my symptons: low oil pressure fouled plug #4 cyl poor fuel economy rough idle #4 cyl compression differs from others

**SABL** · 09-16-2009, 08:21 AM

Hi mack2610,

How many miles on your p/u ?? Ever had the valve covers off to look at the "top end"?? Is the plug oil or gas fouled?? The compression can differ but not by more than 10%.

First thing to do is pull the valve covers and check the oil return passages. If they are blocked the oil is not returning to the pan fast enough to keep the oil pressure up. Blocked passages will also allow oil to seep past the valve stem oil seals and foul the plugs. Make sure your engine is not gunked up and get back with more info.

09-15-2009, 03:02 PM	#1 (permalink)
mack2610 Registered User Join Date: Sep 2009 Posts: 1 OS: win98	valve guide seal 1990 chevy c1500 4.3: i think i have bad valve guide seals # 4 cyl but i'm not quite sure. how can i be 100%? here are my symptons: low oil pressure fouled plug #4 cyl poor fuel economy rough idle #4 cyl compression differs from others

09-16-2009, 08:21 AM	#2 (permalink)
SABL Moderator Relaxation Room Join Date: Jul 2008 Location: Galena, Ohio Posts: 1,205 OS: WinXP SP3	Re: valve guide seal Hi mack2610, How many miles on your p/u ?? Ever had the valve covers off to look at the "top end"?? Is the plug oil or gas fouled?? The compression can differ but not by more than 10%. First thing to do is pull the valve covers and check the oil return passages. If they are blocked the oil is not returning to the pan fast enough to keep the oil pressure up. Blocked passages will also allow oil to seep past the valve stem oil seals and foul the plugs. Make sure your engine is not gunked up and get back with more info. __________________ Every rose has it's thorn