1999 - Suburban - 454 Engine Knock

Hello,

Here is the scenario. I had the lower intake manifold gasket leaking so I replaced it, the upper, injectors (I have 160K miles, thought it was time). New cap and rotor.

When I put it all back together the engine started fine but has severe engine knock. Not in any one valve, but it seems to be all.

My assumption is I have the distributor in wrong, but I'm not sure how that could be.

I believe I put #1 in TDC and put the distributor back in per the instructions on alldatadiy. The only part I'm uncertain of if the timing marks on the front timing chain cover. There doesn't seem to be a scale but just a tab of sorts that sticks out. So I just lined up the harmonic balancer mark with this tab and listend for air coming from #1 cylinder.

What am I missing?

Thanks for the help.

Welcome to AF, I am moving this to the Sub. forum in the Chev. section for more respsonses.

Anyone?

Bring cylinder number one piston to TDC (Top Dead Center) of the compression stroke.
Align the pre-drilled indent hole in the distributor driven gear with the white painted alignment line on the lower portion of the shaft housing. Once the distributor is fully seated, the rotor segment should be aligned with the pointer cast into the distributor base. - The pointer has a (8) cast into it, indicating the distributor is for an eight cylinder engine.make sure the rotor is pointing at the 8 on the distributor.after its installed use a code reader with engine data and check spark advance must be set as close to 0 as possible.but really needs to be at 0 degress.if you do not set timing you will get a ses light and distributor codes.

Bring cylinder number one piston to TDC (Top Dead Center) of the compression stroke.

Align the pre-drilled indent hole in the distributor driven gear with the white painted alignment line on the lower portion of the shaft housing. Once the distributor is fully seated, the rotor segment should be aligned with the pointer cast into the distributor base. - The pointer has a (8) cast into it, indicating the distributor is for an eight cylinder engine.make sure the rotor is pointing at the 8 on the distributor.after its installed use a code reader with engine data and check spark advance must be set as close to 0 as possible.but really needs to be at 0 degress.if you do not set timing you will get a ses light and distributor codes.


Thanks, I did that (minus the scanner so far), but the knock is still pretty pronounced. I'm concerned I might not have found TDC correctly.

Here's what I did to find TDC:

- Took out #1 plug
- Put in the line from my compression tester so I could reach it and the Ratchet I was using to manually move the engine.
- When I heard a puff of air escape from the compression gauge line I then manually cranked the engine until the harmonic balancer mark lined up with the tab (I think it's the timing mark) coming from the front of the timing chain cover.

Does that sound like a reasonable procedured to find TDC?

I know this is an old thread, but did you ever find the problem? I am realizing a similar problem... After pulling the engine twice, I'm thinking that I have a wrong timing chain... It seems that 1999 is a split year and there are 2 different timing chains... I will know more by tomorrow... It seems that GM decided to go "unconventional" and changed whatever setup they had and went like 6 degrees off on late 99 and 00 engines... Then the 454 was cut altogether and then they came out with the 8.1L which has a different timing chain setup, yet similar to the earlier 96-98, and early 99... Even the 502 crate engines have a similar timing chain to the 96-98 and early 99... I have a used 502 crate motor cam, but I didn't know the year, but I am feeling that it's a late 99 or 2000, in which GM must have manufactured the cam on the same basis as the production cams... The chains themselves are the same, but the late 99's use an S830T cam gear and a S815 crank gear... Hope that helps and hopefully this will work!

Mike