OP
OP
notamechanicbrad
Active Member
Known history on this 2011 Expy from my Google Docs
Broken valve spring?
- Thread starter notamechanicbrad
- Start date
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twodollars
Full Access Members
Do you have all of the plugs removed during your test? That will help remove strain on the battery and starter. And keep a charger on the battery during this process. Normally I'd crank until the gauge reaches its highest reading, normally takes a few seconds of cranking to do that.
Gary Waugh
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They also suggest that the throttle valve be fully open when running the compression test to ensure the maximum amount of air is entering the cylinder, in the old days of carburetors that meant having someone press the accelerator pedal to the floor whilst you cranked the engine (with all spark plugs removed). Nowadays with fuel injection, having someone press the accelerator pedal to the floor does not guarantee that the throttle valve is fully open, so you probably just need to keep cranking the engine for longer, until you get the highest reading. In theory the absolute reading is not that critical, you are looking to get similar readings on all cylinders. A low reading may just mean the compression tester is inaccurate but widely different readings across all cylinders indicates a problem (failed head gasket or incorrectly seating/leaking valves, etc).
DieselMonk
Full Access Members
Hmm…. I just read that spread sheet. Did you got rid of the old gas and put a few gallons of fresh fuel in the tank? Do a leak down test, basically putting air pressure into the cylinder and listen if you can hear air coming out of the exhaust or intake.
The compression test you need to check all cylinders and compare them to each other. They should be within 10 to 15% from each other. After this, you need someone that has an automotive type oscilloscope trying to troubleshoot and see what’s off exactly with this thing.
OP
OP
notamechanicbrad
Active Member
Yeah it felt like the battery was getting weak when doing the test. Thats why I didnt do all the cylinders. And it was really windy out and rain clouds moving in. I did have the accelerator all the way to the floor. I figure if cylinder 8 where the misfire is gives me 150 psi then compression on that cylinder is probably not the issue.
I am completely out of time to get this truck back on the road. Ive got to have a running and reliable vehicle for work.
Im buying a 2012 tomorrow morning for 4k. It has high miles, 234000, but runs with no ticking sounds and passed inspection today. Zero trouble lights on the dash. And...ZERO MISFIRES on the condition report. Good clean body and interior. Ill swap my new battery and almost new tires over then sell this 2011 truck for parts or repair. Im sad to see the 2011 go and feel like I should have been able to figure out the problem and fix it. But, its beyond my ability. It has cost me several thousand in lost wages not having a working truck.
I am completely out of time to get this truck back on the road. Ive got to have a running and reliable vehicle for work.
Im buying a 2012 tomorrow morning for 4k. It has high miles, 234000, but runs with no ticking sounds and passed inspection today. Zero trouble lights on the dash. And...ZERO MISFIRES on the condition report. Good clean body and interior. Ill swap my new battery and almost new tires over then sell this 2011 truck for parts or repair. Im sad to see the 2011 go and feel like I should have been able to figure out the problem and fix it. But, its beyond my ability. It has cost me several thousand in lost wages not having a working truck.
DieselMonk
Full Access Members
Nice looking SUV! Yeah… I know what you mean. I’d like to know myself what’s going on with that thing. After all this the engine needs proper diagnosing and those tools aren’t cheap either.
DieselMonk
Full Access Members
I still think there may be something wrong with the intake manifold on #8 sucking air.
OP
OP
notamechanicbrad
Active Member
Yes, the problem probably was the intake manifold sucking air. But...270k miles with 80k of that pulling a trailer, the burnt transmission wiring issues from the exhaust manifold, 3 PCMS... It was time to get into a vehicle that had seen a little less abuse.
I sold that white Expy for $1100 for "parts or repair". I saw it the following day on FB for $2800 stating "runs and drives 100%". In the photos I could see the red and yellow wires I had run to the coil and injector on #8 and I could see the front headlight housings were loose from where I had removed my expensive bulbs.
And thats why I never buy trucks from these small time auto dealers. The guy had about 8 vehicles listed and every one said "runs and drives 100%". There are definitely some good used car dealers out there... But I prefer to buy from individuals who know the history of what I am buying.
RIP 2011 Expy EL.
I sold that white Expy for $1100 for "parts or repair". I saw it the following day on FB for $2800 stating "runs and drives 100%". In the photos I could see the red and yellow wires I had run to the coil and injector on #8 and I could see the front headlight housings were loose from where I had removed my expensive bulbs.
And thats why I never buy trucks from these small time auto dealers. The guy had about 8 vehicles listed and every one said "runs and drives 100%". There are definitely some good used car dealers out there... But I prefer to buy from individuals who know the history of what I am buying.
RIP 2011 Expy EL.
