m_ridzon

I have a rattle on cold startup in my 2009 HHR SS. It sounds like it is coming from the engine. It only lasts a second and is gone but is quite noticeable when it occurs. I have no CEL codes or performance issues. I think folks are going to immediately hypothesize the infamous timing chain issues. I suppose anything is possible, but I would like to first state that I recently repaired the timing chain, tensioner, guides, oil nozzle (the whole shebang) about 20K miles ago. Here's my discussion about it: https://www.chevyhhr.net/forums/prob...e5/#post827769. Admittedly, I did not replace the water pump/balancer chain at that time, but I'm not sure if that would create such a noise.

The vehicle has 120K total miles on it. Are there other known cold startup rattle issues?

Oldblue

So, you had the valve cover off and the front engine cover, but decided to not replace the balance shaft chain or the water pump, well it shoulda been done then, now you’ll have to go back in and change those.
It could be some warm up thing with the catalytic converter, it could be the HPFP getting up to pressure.
If your front guide was broken , did you use the factory top bolt again or replace it as I mentioned in my last post in your other thread?

RJ_RS_SS_350

Please don't be offended, but have you checked the oil level?

m_ridzon

Granted, I know the onus was on me, but I had asked on the forum about the balance shaft chain at that time and the consensus here was that it was probably okay. And upon inspection during the timing chain repair, the balance shaft chain appeared fine. My question would be...do we think the balance shaft chain can cause such a noise? I'm looking for a telltale that might indicate that chain is the culprit before I do a deep dive on the engine.

The front guide was broken, but the bolt was not. So I reinstalled the factory bolt with Loctite figuring it would give me another 100K miles as it initially did. I didn't see any reason to replace it.

No offense taken. I'm looking for good feedback and of course, oil level can affect this so thanks for asking. The answer is...Yes, I have checked the oil level and it is good. Admittedly, I just came due for an oil change, but I wouldn't expect that to cause any significant oil pressure problems (except if I was thousands of miles past due, which is not the case).

I am wondering if temperature is affecting this. I live in frigid NE Ohio. This morning the temperature was in the high 40s and I did not hear the noise. I have noticed it on plenty of bitter cold days though, but again it's somewhat inconsistent; i.e., some cold days it won't make the noise.

I am going to change the oil this weekend. I think I'll monitor the situation from there and see how it progresses, if any. I suppose then my next step might be to pull the valve cover and do an inspection of the chain(s). Unfortunately, I don't think I can get a good look at the balancer chain from that view though. But I can still see the main timing chain.

Oldblue

For the balance shaft chain you can’t see from the valve cover.
Change your oil and filter, if you still hear the noise, then pull the front cover, inspect the tensioner, they do fail but not often.

RJ_RS_SS_350

You can take off the water pump access cover to check the balance shaft chain for tension or slop.

donbrew

Maybe just the HPFP making noise when cold? Or injectors?

Oldblue

Does the HPFP have the silencer in it?

jabr800

My 2009 HHR, 2LT w 2.4L engine, makes the same rattling sound on occasional engine starts, and has been getting more frequent, as I near 115,000 miles.

I had it in the Mom & Pop repair shop today for front end clunk problems (let's talk about that another time), and the Mechanic finally got the rattle on start while I was nearby.

His opinion is it's probably a timing chain cover issue.
Anyway, he said that if I call the GM 800 number and discuss this with them, that they should cover this before 120,000 miles and 10 years.

Is this idea correct before I start something with GM, and does anyone have some supporting documents, tsb's, etc., I can quote, to build my case with them.

Thanks in advance.


jabr800

RJ_RS_SS_350

Well, you can certainly try. I think your car came with a 3 year/36,000 mile warranty? Maybe a 5 year/100,000 mile powertrain? You should not have any expectation, though. Maybe 4 years ago they might have done some goodwill repair. But it was probably fine then. Nothing to lose but a phone call.