Chevy & GMC Vans

New guy here having Astro troubles. Just replaced my timing set to cure a rattling noise, needed replacement but did not solve the problem. The engine makes a rattling noise at higher rpm before shifting into next gear and once I'm up to speed it will clunk as if it's misfiring or jumping time. I also notice that when cold the oil pressure is fine( 40 driving 20 at idle ), but when it warms up it will run at 20 and idle below 10. Any help will be greatly appreciated,have had this thing for e few months and has been constant trouble. by the way it's an 02 with 130,000 miles on it, my last 02 had 250,000 on it and never gave me any of these problems.

Have you scanned for codes??.

Yeah, showing PO300 and PO335.

Still have not figured it out, any ideas?

hope this helps

http://www.obd-codes.com/p0300

http://www.obd-codes.com/p0335

Those codes do make sense.Detonation at speed/timing issue.Careful driving that before you get it fixed.That isn't good for it. :-k

The rattling may well be detonation/pre-ignition. Have you had the truck re-timed?

I didn't think you could adjust timing on these.
The van is parked now,have it torn down finding all kinds of small issues that may be adding to the problem. I did find that the ear on the distributor that the cap screws to is broke off,only one screw holding the cap on can't be good.

Hope you get it sorted out.

Keep us posted.

Thanks, Jim

Thanks y'all, I appreciate all the help. Going now to get some cleaner and rags and break out the Fluke. I have a new distributor on the way too.

soundfx wrote: I did find that the ear on the distributor that the cap screws to is broke off,only one screw holding the cap on can't be good.

Might be an issue there alright.

Yeah, too bad I got to wait 3-7 business days to get the distributor, no drivee the vanee.
Ready to get this thing right so I can clean it up and take some pictures to post.