L5P will barely start, then die Please Help
- Thread starter Rdomeck
- Start date
It fires up easier. It will get some rpm, but not past about 2200? I can hear the turbo spool up now. It is very noisy still. I'd guess I have bent valves, but some have suggested bent pushrods. I'll make time Sunday to pull the valve covers and see what's going on.
Why I thought the gear was correct is that the dot marker was lined up perfectly with the pin in the crank. If it were any other place, I would have taken care of this before I ever started it up
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I find it puzzling that I have 345psi compression. I haven't rechecked it since I have the cam timing correct, but I do not believe the crank gear moved any more since I did a compression check.
I am certain that my crank gear will never move again!!
Why I thought the gear was correct is that the dot marker was lined up perfectly with the pin in the crank. If it were any other place, I would have taken care of this before I ever started it up
. I find it puzzling that I have 345psi compression. I haven't rechecked it since I have the cam timing correct, but I do not believe the crank gear moved any more since I did a compression check.
I am certain that my crank gear will never move again!!
How likely are bent pushrods over bent valves? Anytime I've ever had piston to valve contact, it has bent valves.
Well, I had it back together before I saw the previous message about pulling the valve covers
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Truck just made it on the lift so I can have easier access to do the valve covers.
But yes, I am certainly listening to all the suggestions and really appreciate all the input.
. Truck just made it on the lift so I can have easier access to do the valve covers.
But yes, I am certainly listening to all the suggestions and really appreciate all the input.
Valve covers are at the top of the engine. Lift will only make them harder to reach???? Unless you're lifting the cab onlyWell, I had it back together before I saw the previous message about pulling the valve covers
Truck just made it on the lift so I can have easier access to do the valve covers.
But yes, I am certainly listening to all the suggestions and really appreciate all the input.
TheBac, you seem really pleasant.
Those bolt heads are a special 5 point tamper proof. You have to remove the "egr" on the left valve cover in order to remove the valve cover.
A lift makes reaching the fuel injectors and those connections a lot easier through the fender wells. You are looking straight at them versus laying on top of the engine.
I was able to remove the left valve cover tonight. 4 out of the 8 are bent. One bridge was completely off.
I will pull the glow plugs and pressurize the cylinders with the rockers off. This will tell me if there is any leakage at the valves.
Those bolt heads are a special 5 point tamper proof. You have to remove the "egr" on the left valve cover in order to remove the valve cover.
A lift makes reaching the fuel injectors and those connections a lot easier through the fender wells. You are looking straight at them versus laying on top of the engine.
I was able to remove the left valve cover tonight. 4 out of the 8 are bent. One bridge was completely off.
I will pull the glow plugs and pressurize the cylinders with the rockers off. This will tell me if there is any leakage at the valves.
Also, with a lift and going through the right fender well, you save yourself removing the egr stuff on the right side of the engine. You just have to remove the egr cooler and the connecting pipe to have full access to the right side valve cover.
This was what I suspected from the beginning of the thread. I would guess your valves are fine but a few bent push rods. From the description given and my experience doing salvage rebuilds I suspected the gear on crank turned. Most times we would have put another motor in at that point.
Those PCV bolts come out easy with a drill bit. LOL
Those PCV bolts come out easy with a drill bit. LOL
I was able to get those bolts out by hammering a T30 Torx bit in and easily turning with a 1/4" ratchet. I'll put something normal back in it.
I have learned a lot on this build. I don't think I would fix another one hit this hard. I'm still in good shape financially on it, but the labor has got a little out of control.
I have learned a lot on this build. I don't think I would fix another one hit this hard. I'm still in good shape financially on it, but the labor has got a little out of control.
8 bent pushrods. No bent valves. Found GM pushrods for less than $5 each
. Parts will be here Wednesday!
. Parts will be here Wednesday!I know you already said you found bent pushrods and no bent valves, but I figured I would go ahead and answer this question anyway. I'm not sure what applications you have experienced piston to valve contact with, but in a diesel (at least all the modern diesels used by the big 3 in 1/2, 3/4, and 1 ton trucks) the valves are not angled at all to the piston and the stem of the valve doesn't hang in free space. It is fully over the crown of the piston. Because of the angle and placement of the valve, any valve to piston contact loads the valvetrain in a way that will, more often than not, bend the pushrod becuase it has less compressive strength than the valve. The reason valves get bent on most applications with piston to valve contact is because the piston hits the edge of the valve and pushes up on it which puts a different type of load on the valve in a way that the valve doesn't have much strength.
Yep. I agree. That is some pretty good machining on GM's part. A thousandth or two out and it would bend the head to not sealing up. I grew up on air cooled German stuff. I work on a lot of European and Asian stuff. Most, if not all are interference engines and the valves are at an angle.
Just happy to finally find what's going on. I spoke to two people and shared a video of this running and mentioned the high fuel pressure. Both suggested that the noise was the fuel injectors. I did a compression check which provided numbers suggesting nothing was going on in the valve train.
I have been schooled on this one. You will pay for an education one way or another.
I am exactly 2 years from buying this project and bringing it home.
Will be very nice to drive it this weekend. I did a full color change on it. Painted a lot of the chrome as I'm not a fan of it.
things go back together smoothly.
Just happy to finally find what's going on. I spoke to two people and shared a video of this running and mentioned the high fuel pressure. Both suggested that the noise was the fuel injectors. I did a compression check which provided numbers suggesting nothing was going on in the valve train.
I have been schooled on this one. You will pay for an education one way or another.
I am exactly 2 years from buying this project and bringing it home.
Will be very nice to drive it this weekend. I did a full color change on it. Painted a lot of the chrome as I'm not a fan of it.
things go back together smoothly.Attachments
Wow thats a nice looking truck. What color did you use? I’m liking it. Glad your maybe on the home stretch with this thing. I know exactly what all you did as I’ve done many of them.