#1 PISTON FAILURE DIAGNOSTIC TIPS

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Jim LaGuardia
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Location: San Bernardino Ca
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#1 PISTON FAILURE DIAGNOSTIC TIPS

Post by Jim LaGuardia »

Since this is the 4th or 5th time I have come across this issue, I decided once again to share some more of my mountain of info with the group.
There are a couple issues that can lead to very expensive repairs from single piston loss to all 4 from lack of oil.
One issue is improper oil pump installation, lack of or blown out copper gasket(if the forward pump mounting bolt breaks).
The other issue is cam plug failure.
Here are the tell tails I observed: excessive lifter or rocker arm clatter on cold start up or after sitting for over an hour, delayed oil pressure(light should go out within 2-4 seconds while cranking), loss of #1 piston.
Why it happens: The cam has an aluminum bore plug in each end.
These plugs can blow out over time, especially in warmer climates or if overheated repeatedly.
If the front plug blows out, all the lifters will clatter and oil pressure will fall resulting in loss of all 4 pistons(rings will sieze, skirts will gall)

If the rear plug fails, the stop sheet for the cam gear bolts still covers the bore and keeps the plug from falling into the gears, but the oil will leak out of the cam past the plug and stop sheet gap when the engine is turned off(cam drains). This will over time result in at least 1 piston to fail(#1). This is due to lack of oil in the cylinder on start up.
The fix is to remove the cam and replace the bore plugs.
There are two options depending on the hardness of the cam, option 1 is to tap the bore and use a threaded plug.
Option 2 is to just replace the plugs with factory replacement plugs and sleeve retaining Locktite. (Cam Plug #7121051071)
The repair can be done in the vehicle and requires all rocker arms, push rods, distributor, and fuel pump removal as well as the transmission ,flywheel and timing cover.
Before removing the cam you will have to raise the passenger side up at least 10" or park on ramps to tilt the engine(very important), then use 8 thin strong telescoping magnets to hold the lifters from falling into the engine. If they fall out you will be tearing down the engine :shock:
After securing the lifters, you can remove the cam, replace the plugs and then re assemble.
And in advance, I will not post pic's on this one.
Merry Christmas
Cheers, Jim LaGuardia
http://smg.photobucket.com/albums/v510/Goatwerks/
"Arch Magus of Machines."
EvanH
Posts: 175
Joined: Wed Apr 14, 2004 4:14 pm
Location: Northern Utah
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Post by EvanH »

Jim,

You make Pinz ownership sound like such a joy! :?

I'm the one who bought Andre's 710/712 hybrid. I'm flying into LA on Friday...I hope I get the chance to meet you and see your EFI during my visit.

Andre offered to keep me warm during my visit. :shock: Actually, he offered me use of his RV as a place to sleep. I'll be looking for advice on where to visit while I'm there!

Thank you for your habit of posting all the helpful hints!

-Evan
Jim LaGuardia
United States of America
Posts: 1704
Joined: Wed Apr 14, 2004 3:42 pm
Location: San Bernardino Ca
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Post by Jim LaGuardia »

Evan, your new truck is already here for minor service. I will be happy to show you the EFI and even take you for a spin in it.
I'll even show you some pictures of earlier systems that have been used.
You will see very little difference in a couple of them.
Cheers, Jim LaGuardia
http://smg.photobucket.com/albums/v510/Goatwerks/
"Arch Magus of Machines."
Erik712m
Posts: 1553
Joined: Sun Jan 21, 2007 7:52 pm
Location: Wichita, Kansas

Post by Erik712m »

Evan, Congrats on your new pinz. I have worked with Andre in the past. Couldn't deal with a nicer guy.
Andre offered to keep me warm during my visit. Actually, he offered me use of his RV as a place to sleep.
Better watch it.. there a little different in California. He'll get you cornered and start speaking prop eight. :lol:
I hope I get the chance to meet you and see your EFI during my visit.
After you've driven in Jim's you'll be chomping at the bit to get one.


Jim, sounds like the moral to the story is check the oil levels, and have a professional install the oil pump. And here I was thinking they were military tough and needed no oil.
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