For the last 4 months or so my truck has been running poorly and I thought it was something to do with the valvetrain, so I took it to the shop. The problem is because of my tune most shops won't even touch my truck so after a ton of searching I found a shop who I thought could help. Long story short after running a few diagnostics, they found nothing wrong with it so they figured it was probably a mechanical problem like I originally thought. However, because of the aftermarket cam, springs and pushrods they were not able to help me any further because they can only work on an engine that is 100% stock internally.

I then took my truck to another shop that does aftermarket installs/work, but after they listened to it and test drove it they said it drove fine to them. Afterwards they dynoed my truck on a dynojet and no surprise to me, it only put down 282/282. One thing I should mention was that the pull was made is 2nd gear and he said he let out of it at about 5800 rpm even though I have my shift point set to 6200 rpm during the 2-3 shift. But honestly I don't think the additional 400 rpm would have made much difference, my truck is definitly not putting down good numbers given my mods. My next move would be have them basically tear down the engine, but I don't want to go through all of that time and money just for them to say everything is ok.

Just to give a little more info, I'm had my cam since august 2006 and have probably put about 20-25K miles on the cam, my truck only has 47K miles on it total. I have however been VERY rough on my truck over the years as well. I'm running out of options here, PLEASE HELP!

 

do a compression test on it

 

How can I do that, doesn't the cam mess with the CR? I mean if it was the stock cam ok, but with a different cam I don't know. Anyone else?

 

You're confusing compression ratio with compression...by doing a compression test you're verifying that the cylinders are sealing, and checking for things like worn rings, burnt valves, blown head gaskets, etc.

 

check for compression, make sure ur rings are good, no burnt valves, etc.

 

Defenetly do a compression test on the motor, if one/multiple cylinders are lower than the others you can do a wet compression test, if both show low comp, then you can do a leak down test to check and see where it is going. Good luck and keep us updated

 

Thanks for the replys, I'll see if any of that works.

 

How much horsepower do you think your out? Looks like maybe 20-25hp total with a cammed, exhaust/intake and tuned 5.3L.

 

Do you still have the factory CATs and y-pipe. If so it may be your cats getting clogged up due to the cam and tune. Just a thought.