alfolsee2000

I had to replace engine head on my 2.2 2007 hhr due to broken camshaft caps and bolts broken off in head. Replaced with used head from low mileage 2007. The engines starts, idles fine for 2 minutes at 1200 rpm, then slows to 6-800 and idles rough. The car seems to run fine over1500 rpm, 70 mph at 2500 rpm, same as before, but will sputter at stop sign and sometime stop. Replaced spark plugs, all coil packs firing, all injectors cleaned, throttle body cleaned, replaced air filter...no help. Could time chain be off.?..removed valve cover and marks seemto line up...by the way, didnt see any colored links on the timing chain...will check this again inthe morning....any other ideas.

donbrew

Sounds like the timing chain/balance chains are not synced. The colored links are tough to see, one is green/blue one is silverish, if I remember right. Both chains do need to be synced.

When I screwed mine up, I got a CEL that I could clear for a start but came back the next start. I did not pull a code since I knew what the problem was and it was not my problem in 24 hours (I traded in).

PM me if you need an service book.
Check your PM for a link, if you want it.

alfolsee2000

well, i dont think mine will traded anytime soon, will have to figure it out. i probably do need a service book. I thought i saw a link to one via drop box but it did not show up. I will look harder for the links tomorrow. We never touched the balance chain, so just have to deal with the timing chain.

donbrew

just go to your PM and click the dropbox link it will download a pdf.

The point is the 2 chains need to be synced to each other and to their components.

alfolsee2000

thanks, will try and andswer tomorrow.

alfolsee2000

I replaced the timing chain, put crank on tdc, lined up chain mark to crankshaft mark, then lined up intake sprocket marks to chain mark and exhaust sprocket to chain mark. All looked ok. I then turned the crankshaft a number of times by hand, but the marks never did come back to original settings. Should they, and how many turns?

ChevyMgr

1.Install the balance shaft drive chain with the colored links lined up on with the marks on the balance shaft drive sprockets and the crankshaft sprocket. Use the following procedure to line up the links with the sprockets:

Orient the chain so that the copper colored and chrome links are visible.

2.1 Place the uniquely colored link (1) so that it lines up with the timing mark on the intake side balance shaft sprocket.

2.2 Working clockwise around the chain, place the first matching colored link (2) in line with the timing mark on the crankshaft drive sprocket. (approximately 5 o'clock position on the crank sprocket).

2.3 Place the chain (3) on the water pump drive sprocket (alignment is not critical).

2.4 Align the last matching colored link (4) with the timing mark on the exhaust side balance shaft drive sprocket.

donbrew

And Then you can install the timing chain. So that the colored links on the crankshaft line up and the marks on the cams line up. The crankshaft mark should be at approx. 5:00 position (that would be TDC). It is important to have the 2 chains synced to each other as well as their own sprockets.

I hope that you decided to save yourself a lot of grief and replaced the chain guides and oil spigot. If not, you will be doing this all again.

Yes, if they are all aligned they will match back up, I think after some multiple of 4 revs., I don't remember exactly. DONOT rotate counter clockwise, or the chain will jump teeth.

Bottom line is : You must do it the way the book says to do it exactly, or it will not work.

alfolsee2000

Followed exactly and the car stated rigt up and idled fine. Thanks