| Trouble [message #145486] |
Tue, 04 October 2011 14:48  |
|
|
I have an engine problem; low compression in 1-3; 6-8. I pulled the heads and there is a very slight depression between those cylinders and that is where the head gasket blew out. I had the heads done in a San Diego head shop (recommended by Steve Ferguson) several years ago and have only put on less than 3K miles. Engine has not overheated and valves look good. My plan is to take the heads to a good shop in Reno NV and have them machined to a good flat shape again. Any suggestions that would be beneficial would be appreciated.
geo groth '73 260 Sequoia
Carson City Nevada 89703
|
|
|
|
| Re: Trouble [message #145550 is a reply to message #145486] |
Tue, 04 October 2011 20:58  |
 |
Matt Colie
Messages: 8547
Registered: March 2007
Location: S.E. Michigan
Karma: 7
|
Senior Member |
|
|
| ggroth wrote on Tue, 04 October 2011 15:48 |
I have an engine problem; low compression in 1-3; 6-8. I pulled the heads and there is a very slight depression between those cylinders and that is where the head gasket blew out. I had the heads done in a San Diego head shop (recommended by Steve Ferguson) several years ago and have only put on less than 3K miles. Engine has not overheated and valves look good. My plan is to take the heads to a good shop in Reno NV and have them machined to a good flat shape again. Any suggestions that would be beneficial would be appreciated.
|
George,
Look under "455 heads from swap", but it is partly wrong.
The typical failure is where the exhaust valves are adjacent. This is where things get rough when the cooling system looses pressure.
Yours did not, the 1-3 & 6-8 indicates a different form. But, it lost coolant flow rate or the coolant was over temperature - still a cooling system problem. The reason that pair got in trouble is that coolant comes back through the block and then forward through the cylinder heads, so, the front is hottest. That means that the system held pressure, but could not manage the heat load. The temperature gauge should have shown this while it was happening.
You still need to find a cooling system problem.
Matt
Matt & Mary Colie - Chaumière -'73 Glacier 23 - Members GMCMI, GMCGL, GMCES
Electronically Controlled Quiet Engine Cooling Fan with OE Rear Drum Brakes with Applied Control Arms
SE Michigan - Near DTW - Twixt A2 and Detroit
|
|
|
|
| Re: Trouble [message #145565 is a reply to message #145550] |
Tue, 04 October 2011 22:56 |
|
|
Thanks Matt; I'll certainly check everything in regard to that. I wonder if something is blocking coolant flow in the heads? Another friend looked at the head gaskets and said that he's seen this kind of failure before w/that brand of head gasket. I got them from Mondello. We are going with Napa FelPro when we get the head machined and ready to go back together. My records indicate that the previous head job did machine the heads properly. There is a note that you are "blocked", and I don't understand that as I've done nothing to do it. I can see your posts by looking at them in another way. By the way, we cannot see any signs of overheating in the block or heads and I never saw it on the gauges.
geo groth '73 260 Sequoia
Carson City Nevada 89703
|
|
|
|
| Re: [GMCnet] Trouble [message #145572 is a reply to message #145565] |
Tue, 04 October 2011 23:20 |
Wayne Newland
Messages: 75
Registered: February 2004
Karma: 0
|
Member |
|
|
Could it be that "blocked" means that the crossover is blocked? That would
be good.
Wayne Newland F9300 75 Palm Beach Sebastian, Fl
-----Original Message-----
From: gmclist-bounces@temp.gmcnet.org
[mailto:gmclist-bounces@temp.gmcnet.org] On Behalf Of George Groth
Sent: Tuesday, October 04, 2011 11:57 PM
To: gmclist@temp.gmcnet.org
Subject: Re: [GMCnet] Trouble
Thanks Matt; I'll certainly check everything in regard to that. I wonder if
something is blocking coolant flow in the heads? Another friend looked at
the head gaskets and said that he's seen this kind of failure before w/that
brand of head gasket. I got them from Mondello. We are going with Napa
FelPro when we get the head machined and ready to go back together. My
records indicate that the previous head job did machine the heads properly.
There is a note that you are "blocked", and I don't understand that as I've
done nothing to do it. I can see your posts by looking at them in another
way. By the way, we cannot see any signs of overheating in the block or
heads and I never saw it on the gauges.
--
geo groth '73 260 Sequoia
Carson City Nevada
_______________________________________________
GMCnet mailing list
Unsubscribe or Change List Options:
http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
_______________________________________________
GMCnet mailing list
Unsubscribe or Change List Options:
http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
|
|
|
|
GMCforum
Search
Help
Register
Login
Home
