| Power loss Engine rattle [message #230182] |
Mon, 18 November 2013 16:28  |
Keith V
Messages: 2337
Registered: March 2008
Location: Mounds View,MN
Karma: 0
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Not my coach!
My friend Paul, he must be too shy to ask you guys 
Anyway he emailed me this;
a) lost pwr on freeway - 10 and Foley.
b) temp a tick above 1/4 on stock gauge.
c) oil press exc. according to stock gauge.
d) barely made it home maintaining 50mph.
e) Rough running with noise from left rear of motor, and front. Sounded like water pump. Rattle can sound both places.
I don't have a stock temp sender, it 'a little above 1/4' really hot?
Sounds like a valve or two to me..
What do you engine guys think?
I'm scheduled for a look see on Wednesday
Keith Vasilakes
Mounds View. MN
75 ex Royale GMC
ask me about MicroLevel
Cell, 763-732-3419
My427v8@hotmail.com
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| Re: Power loss Engine rattle [message #230184 is a reply to message #230182] |
Mon, 18 November 2013 16:45  |
Bob de Kruyff
Messages: 4260
Registered: January 2004
Location: Chandler, AZ
Karma: 1
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| Keith V wrote on Mon, 18 November 2013 15:28 |
Not my coach!
My friend Paul, he must be too shy to ask you guys
Anyway he emailed me this;
a) lost pwr on freeway - 10 and Foley.
b) temp a tick above 1/4 on stock gauge.
c) oil press exc. according to stock gauge.
d) barely made it home maintaining 50mph.
e) Rough running with noise from left rear of motor, and front. Sounded like water pump. Rattle can sound both places.
I don't have a stock temp sender, it 'a little above 1/4' really hot?
Sounds like a valve or two to me..
What do you engine guys think?
I'm scheduled for a look see on Wednesday
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Off hand that temp reading even with the old sender should be OK. It almost sounds like the timing chain may have jumped a tooth but I'm not sure if our chains can or will get loose enough to jump.
Bob de Kruyff
78 Eleganza
Chandler, AZ
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| Re: Power loss Engine rattle [message #230186 is a reply to message #230182] |
Mon, 18 November 2013 17:01 |
kerry pinkerton
Messages: 2565
Registered: July 2012
Location: Harvest, Al
Karma: 15
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To only get 50mph out of it, it sounds like a two cylinder problem of some flavor. Such as:
MAJOR vacuum leak affecting timing?
Jumped time?
Carb gasket blown out?
Major failure in the head causing two adjacent cylinders to loose compression?
I've had a spark plug come apart. Whole center blew out and lost all compression on that cylinder. Made a hell of a racket too. That said, I doubt a single plug would cause that much power loss.
Be interested in hearing what the problem is.
Kerry Pinkerton - North Alabama
Had 5 over the years. Currently have a '06 Fleetwood Discovery 39L
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| Re: [GMCnet] Power loss Engine rattle [message #230236 is a reply to message #230231] |
Mon, 18 November 2013 22:46 |
Keith V
Messages: 2337
Registered: March 2008
Location: Mounds View,MN
Karma: 0
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Yeah it's a guessing game at this point.
Just needed to brainstorm a little.
So compression tester, stethoscope, and pull the valve cover.
Harmonic balancer, waterpump bearings...
I'll let you know after wednesdays playtime
Keith Vasilakes
Mounds View. MN
75 ex Royale GMC
ask me about MicroLevel
Cell, 763-732-3419
My427v8@hotmail.com
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| Re: [GMCnet] Power loss Engine rattle [message #230243 is a reply to message #230226] |
Tue, 19 November 2013 03:04 |
Ken Burton
Messages: 10030
Registered: January 2004
Location: Hebron, Indiana
Karma: 10
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| Ken Burton wrote on Mon, 18 November 2013 21:04 |
Stuck advance weights in the distributor?
Without hearing it is impossible to tell. We are all just guessing.
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I only put this up here in case this is extreme ignition ping (detonation) that he is hearing. It might be interesting to pull the vacuum hose to the distributor and see if it still acts the same.
Ken Burton - N9KB
76 Palm Beach
Hebron, Indiana
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| Re: [GMCnet] Power loss Engine rattle [message #230257 is a reply to message #230243] |
Tue, 19 November 2013 08:54 |
Keith V
Messages: 2337
Registered: March 2008
Location: Mounds View,MN
Karma: 0
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Good idea, I'll do a video and try the vacuum line thing.
There are so many things it could be the more ideas the better...
Keith Vasilakes
Mounds View. MN
75 ex Royale GMC
ask me about MicroLevel
Cell, 763-732-3419
My427v8@hotmail.com
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| Re: [GMCnet] Power loss Engine rattle [message #230269 is a reply to message #230257] |
Tue, 19 November 2013 10:29 |
Ken Burton
Messages: 10030
Registered: January 2004
Location: Hebron, Indiana
Karma: 10
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| Keith V wrote on Tue, 19 November 2013 08:54 |
Good idea, I'll do a video and try the vacuum line thing.
There are so many things it could be the more ideas the better...
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I really doubt this is your problem but it is a quick check that will retard your timing by about 10 degrees. If it does make a difference then you need to pull the distributor cap and verify that the advanced weight are not hung up.
Ken Burton - N9KB
76 Palm Beach
Hebron, Indiana
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| Re: [GMCnet] Power loss Engine rattle [message #230276 is a reply to message #230226] |
Tue, 19 November 2013 10:53 |
Bullitthead
Messages: 1411
Registered: November 2013
Karma: 5
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Centrifugal advance should be all in by 1500-1800 RPM, should not cause lack of power or pinging at highway speeds. Would cause problems at low engine speeds and very hard starting. However, if they are refusing to advance, that will cause a huge loss of power and fuel economy and it will feel like a plugged exhaust, slipped timing chain, or driving with the parking brake on.
Terry Kelpien
ASE Master Technician
73 Glacier 260
Smithfield, Va.
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| Re: [GMCnet] Power loss Engine rattle [message #230279 is a reply to message #230276] |
Tue, 19 November 2013 11:07 |
Ken Burton
Messages: 10030
Registered: January 2004
Location: Hebron, Indiana
Karma: 10
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| Bullitthead wrote on Tue, 19 November 2013 10:53 |
Centrifugal advance should be all in by 1500-1800 RPM, should not cause lack of power or pinging at highway speeds. Would cause problems at low engine speeds and very hard starting. However, if they are refusing to advance, that will cause a huge loss of power and fuel economy and it will feel like a plugged exhaust, slipped timing chain, or driving with the parking brake on.
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My full centrifugal advance is not in until 2500 rpm. It is 18 degrees at 2500. I just looked at the distributor curve sheet on mine.
As I said before I really do not think it is his problem but with out hearing the noise I do not know if it is ignition ping he is hearing or not.
It is a quick check to pull the vacuum hose and see if it makes any difference.
Ken Burton - N9KB
76 Palm Beach
Hebron, Indiana
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| Re: [GMCnet] Power loss Engine rattle [message #230289 is a reply to message #230279] |
Tue, 19 November 2013 11:58 |
Bullitthead
Messages: 1411
Registered: November 2013
Karma: 5
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You have some really stiff springs on there Ken! Most of the ones I see have almost all of the advance in as soon as the engine runs and just a few degrees left for the next 1000 rpms. Perhaps they were weak because all of them are old stuff. As an aside, are you running manifold vac to your advance or ported (above the plate)on your setup? I don't get the response I like when using ported vacuum on any of my vehicles with vacuum advance. I like the full advance with no engine load that you get with manifold vacuum, and then when I stick my foot in it the timing backs off so I get power without ping. I've done it that way since my first car and had many people say that's wrong, but they couldn't argue with 14-16 mpg after a tire burnout on the Oldsmobile 425 in my Dads 98! Wish I could get that mileage in the GMC...
And you are correct about pulling the advance hose (gotta plug that if it manifold vac)to see if his noise stops. He might also have run low on coolant and made the heads hot which would also cause pinging that would be relieved by backing the timing off.
Terry Kelpien
ASE Master Technician
73 Glacier 260
Smithfield, Va.
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| Re: [GMCnet] Power loss Engine rattle [message #230296 is a reply to message #230289] |
Tue, 19 November 2013 12:15 |
Ken Burton
Messages: 10030
Registered: January 2004
Location: Hebron, Indiana
Karma: 10
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I am using a Dick Paterson rebuilt distributor. He set the advance curve. It is set at 12 BTC static, 10 degrees maximum vacuum advance at 12" of vacuum and 18 centrifugal at 2500 rpm for a total possible of 40 degrees at 2500 rpm.
I run ported vacuum.
Ken Burton - N9KB
76 Palm Beach
Hebron, Indiana
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| Re: Power loss Engine rattle [message #230410 is a reply to message #230182] |
Wed, 20 November 2013 07:49 |
Neal Krisher
Messages: 54
Registered: November 2013
Location: Apple Valley, MN
Karma: 0
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One more tool to grab if you have one, is an infrared temperature gun. I've used these to find a dead cylinder on a few things. If the exhaust port is cold, that cylinder isn't firing.
If you'd want another set of eye's and ears let me know as I'm off today.
"Life has no instruction manual. Parts and labor can be impossible to find. Many go down the road with parts that are in need of service. A breakdown is eventual."
1975 26', TZE165V100301 Project/Driver
1977 26' TZE167V100439 Parts unit
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| Re: Power loss Engine rattle [message #230415 is a reply to message #230182] |
Wed, 20 November 2013 08:28 |
JohnL455
Messages: 4447
Registered: October 2006
Location: Woodstock, IL
Karma: 12
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Can you expound on "rattle". Is it random like pinging or fixed rhythm as in rod knock or valve train or fuel pump arm? If you can determine if it if engine speed or half engine speed we can really narrow the search. Does it do this in park at idle or at above idle? A rubber hose stethoscope may point you closer.
John Lebetski
Woodstock, IL
77 Eleganza II
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| Re: Power loss Engine rattle [message #230430 is a reply to message #230410] |
Wed, 20 November 2013 09:59 |
Keith V
Messages: 2337
Registered: March 2008
Location: Mounds View,MN
Karma: 0
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Senior Member |
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| Neal Krisher wrote on Wed, 20 November 2013 07:49 |
One more tool to grab if you have one, is an infrared temperature gun. I've used these to find a dead cylinder on a few things. If the exhaust port is cold, that cylinder isn't firing.
If you'd want another set of eye's and ears let me know as I'm off today.
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Hi Neal
The coach is in Andover, I'm sure paul would be happy to have another set of ears to help out.
We plan on working on it starting at 6 pm...
Yes it will be dark.
I sent you a PM w contact info
Keith Vasilakes
Mounds View. MN
75 ex Royale GMC
ask me about MicroLevel
Cell, 763-732-3419
My427v8@hotmail.com
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| Re: Power loss Engine rattle [message #230432 is a reply to message #230415] |
Wed, 20 November 2013 10:00 |
Keith V
Messages: 2337
Registered: March 2008
Location: Mounds View,MN
Karma: 0
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Senior Member |
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| JohnL455 wrote on Wed, 20 November 2013 08:28 |
Can you expound on "rattle". Is it random like pinging or fixed rhythm as in rod knock or valve train or fuel pump arm? If you can determine if it if engine speed or half engine speed we can really narrow the search. Does it do this in park at idle or at above idle? A rubber hose stethoscope may point you closer.
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John,
I haven't heard the coach, I have no idea.
we will will try to get some video posted
Keith Vasilakes
Mounds View. MN
75 ex Royale GMC
ask me about MicroLevel
Cell, 763-732-3419
My427v8@hotmail.com
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