Low Compression - 87 305 - The 1947 - Present Chevrolet & GMC Truck Message Board Network

starsky1231 · 01-13-2003, 05:57 PM

I have a 1987 Chevy C10 w/ a 305. Compression in cylinder 6 is well below the others. Any possible options rather then pulling it and resleeving the chamber. Thanks.

**swervin ervin** · 01-13-2003, 07:56 PM

I would pull it, and replace it with a 350.

Seriously, you don't resleeve it. It sounds as though it has quite a few miles, so it's probably ready for a rebuild. But, it's possible other things could be causing it, such as maybe valves. My vote would be rings are worn.

J-Spec C10 · 01-13-2003, 08:03 PM

Have a shop do a leakdown test. If the air is coming from the dipstic tube, then try new rings. If it comes from the carbuetor or muffler, then do valves. But as Mike says, a rebuild might not be a bad idea.

gchemist · 01-14-2003, 12:12 AM

First Welcome to the board.
How did you do the compression check? Was the engine hot or cold? Did you crank at least three times to build up pressure? How many miles on the engine? A little more info would be helpful. Sounds like you're familiar with mechanics.

01-13-2003, 05:57 PM	#1
starsky1231 Registered User Join Date: Jan 2003 Location: St Louis MO Posts: 20	Low Compression - 87 305 I have a 1987 Chevy C10 w/ a 305. Compression in cylinder 6 is well below the others. Any possible options rather then pulling it and resleeving the chamber. Thanks.

01-13-2003, 07:56 PM	#2
swervin ervin You get what you pay for Join Date: Dec 1999 Location: Cherryville, NC Posts: 4,798	I would pull it, and replace it with a 350. Seriously, you don't resleeve it. It sounds as though it has quite a few miles, so it's probably ready for a rebuild. But, it's possible other things could be causing it, such as maybe valves. My vote would be rings are worn. __________________ Mike 1985 Chevy C-10

01-13-2003, 08:03 PM	#3
J-Spec C10 Whats this wire for?.... Join Date: Dec 2002 Location: Barrie, Ontario, CANADA Posts: 378	Have a shop do a leakdown test. If the air is coming from the dipstic tube, then try new rings. If it comes from the carbuetor or muffler, then do valves. But as Mike says, a rebuild might not be a bad idea. __________________ Kyle CANADIAN CONNECTION '82 C10 Resto-Custom--> * 2 1/4" manifold back dual exhaust with Hooker Aerochambers & High Flow Cats Taylor Ignition Wires Centerline 15" Telstars with 32"x10" mudders

01-14-2003, 12:12 AM	#4
gchemist BAD BOW-Silverado XST Join Date: May 2000 Location: Senior Member from Austin, TX Posts: 6,431	First Welcome to the board. How did you do the compression check? Was the engine hot or cold? Did you crank at least three times to build up pressure? How many miles on the engine? A little more info would be helpful. Sounds like you're familiar with mechanics. __________________ Gerardo a.k.a. Mad Chemist Silverado XST videos

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