So I replaced my head gasket (didn't think it would be a problem as I have dome many before with no issues).

Well I start the car and "KNOCK KNOCK KNOCK" and smoke or maybe exhaust gases coming out from the engine bay somewhere. I'm pretty sure it was coming from the firewall side not the front of the car side.

So i turn it off and retrace my steps in my head. The car was running fine before this HG change minus the coolant burning and misfire in cylinder 5 which also had slightly lower compression than the other 5 cylinders. ~120psi with the others ~150psi.

I doubt it is rod knock. I think I am hearing the pistons hitting the valves , but it doesn't sound like it's happening too quickly. Like 4 knocks per second maybe.

I locked the cams together while at TDC. I removed the cam gears and went on to the removal of the valve cover to get to the cams. I removed the cams together while still locked with the volvo cam locking tool.

I also painted marks on the timing belt in relation the the cam gears. I put it all back together the same way I found it and that's when the above happened (KNOCK KNOCK KNOCK).

So I must have screwed up somewhere, but I have no clue where.

The exhaust cam gear has 3 oversized holes which allows for adjustment. The intake cam gear has nothing which sucks because I can mount it upside down if I wanted to. Am i missing something here?

I'm hoping to get the timing right and hoping for the best on the valves though I know I'm probably screwed.

Please any advice will help.

 

I was watching a video the other day on you tube how to do a cam seal they show you step by step on the timing hope this helps.

 

It's not the valves hitting the pistons. You only hear that briefly before the car dies.

 

That's good to hear. I turned the car off pretty immediately. I did start it one more time for about 5-10 seconds to try to see/hear where knocking was coming from. Man I am so confused on why this is happening.

 

what video is this? I've watched a ton to make sure I had a heads up when working on this motor. Most just showed lining up timing marks to timing cover notches when at TDC. Which I did.

Did you see any other information on this? Maybe I missed something

Thanks

 

On the bright side, at least you didn't pay someone to mess up your car.

Whenever the timing belt comes off, when it's back on first thing you do is turn the crank pulley two revolutions by hand to check for interference. A simple thing that can save you a lot of heartache.

 

As migpro indicated, you can still turn the crank manually to confirm there is mechanical interference. Perhaps something is broken or forgotten following HG change?

 

AND

How simple yet so overlooked!!!! Dang I wish I had known/thought of this before I started the car. I guess doing a few HG changes with no problems gave me the confidence that everything would be fine.

How would I know there is interference? Would there just be resistance? Like more resistance than normal? Or...?

Thanks

 

Yes there's resistance. As in - clunk - and you can no longer turn the crankshaft by hand. If you want to be certain take the spark plugs out so there's no compression and then any resistance you feel has to be mechanical.

 

So I took out the spark plugs and rotated by hand and it seems to be fine. It's always a lot of resistance to first get going, but once it gets moving it seems okay to me. I'm assuming if I hit a valve it would be DAMN HARD to get past it by hand. Right?

I also got an inspection camera from local hardware store (so i can return it after hehe) but it doesn't fit into the spark plug holes. From what I could see with it though seems to be fine. I didn't see any debris or a socket (which is what I was really scared of). I also put a magnet pickup tool down in the combustion chambers to see if it would stick to anything, like tools that may have accidentally fell into the chamber, but nothing.


I'm now thinking it's just an exhaust leak. Like ES6T said, my car should have dies if the valves were indeed hit. And there is smoke coming out of the engine somewhere in the back (where the exhaust manifold is).

But I've never heard of an exhaust leak causing a loud knocking sound. Has anyone else? It isn't a ticking sound. It comes on immediately (which scares the **** out of me as I think I am going to F up the engine.. so I turn the car off).

I will take the heat shield off and try to inspect the manifold along with tightening them down some more, but I don't really know what else to look for here.

 

Alright. An update. The gasket I used (Felpro) was not a single sheet of metal. It was 5 little ones for each exhaust port. Well one of them wasn't on one of the studs so therefore didn't seal properly.

I fixed then started and the knocking is gone! Woohooooo.

But I still have an exhaust leak as there is still smoke, although less of it, coming out of the engine bay in the back. I'm assuming it's the gasket.

I also have a slow coolant leak on the bottom of the car next to the fuel lines under the passenger seat. Really weird spot. I have no idea why there, but my guess is there's a leak in the heater core and it's somehow making it's way there.