Yoboyd06

I replaced both head gaskets on 02 3.0 b6 along with timing belt, rollers, tensioner, water pump and couple other things. I got both heads pressure tested and resurfaced. The guy at the machine shop said everything was ok and that the valves were good. I got the car back together and starts but runs really rough and I can hear that there is no compression in the engine. I'm pretty sure the timing was done correctly I used the cam locking tools and the crank was lined up correctly. I did a compression test all cylinder seemed ok except number three I figured its a bent valve. My question is, How can my valve have possibly bend I didnt hear a clank or any kind of noise when I first started the engine. Also since I have to take off the head do I have to replace my brand new headgasket that I just replaced? Do I have to replace all valves if there is only one or two that are bent?(I am a broke college student I don't want to spend money if I don't have to.) How hard is it to replace the valves? should I just take the head to a machine shop to let them replace them or is it pretty simple to do? Any help is much appreciated.

Prospeeder

Ok number three is the cylinder thats at top dead center on timing. If you left it at top dead center, and didnt have the cam in a spot where the valve was fully closed you would have just smooshed the valve right into the piston as you torqued the head down. Always move the engine slightly off TDC before installing the heads.

Pull the one head, replace the one or 2 or 3 valves that are bent, replace the one headgasket.

Yoboyd06

I see I see... Well I had the cam locks on the head when I put the head on. I do remember seeing some valves opened with the head on, I don't remember which cylinder it was. Do I have to replace the bolts too? they were brand as well. I Thought that If I had the cam locks on the head and the crank at the TDC line it would be good to go and nothing would be in the way. I wont make that mistake again. I really appreciate all the help.

Prospeeder

Now before you go way to much further, you have run it awhile and revved it up to make sure its not just a little piece of carbon or debris holding a valve open?

sylviesdad

When you say "always move the engine slightly off tdc before installing the heads" do you mean just while installing the head ? The cam locks would be on still, right ? Then return the crank to TDC and install the timing belt ?

turbo510

What I have read on another forum is to rotate the crank about 45 degrees counter-clockwise from TDC, which brings all pistons a safe distance away from the valves. That is for situations where the camshafts can be in any arbitrary position when the heads are put on. However, with the crank at TDC (#3 cylinder I believe) and with your cam tools already installed, the valves should already be in the proper places for the head installation. So if that is how you installed the heads, that shouldn't have bent any valves.