Timing Chain Issue
 

Hi all:

My daughter said her HHR was making a "noise". She lives out of town, so I had to wait a few days until she brought it to me.

I had forgotten to do the timing chain in her 2006 HHR 1LT (2.4L) in a more timely manner.

She had the check engine light on due to the "slow evap leak" code. I was going to fix that soon before inspection time. This hid the codes that indicated that it was time to replace the chain (cam "A" and can "B" position is not what was commanded).

Over the weekend, I replaced the chains. It had not slipped a tooth, but was loose. As a matter of fact, it had cut through the upper timing chain guide. So I did the usual chain replacement and put it together. Also changed the oil and filter. I drove it and then checked the codes. There was a code for cam "B" (exhaust) position was not what was commanded.

So I decided to replace the solenoid for cam "B" (I had a spare set of new solenoids). When I removed the solenoid, there were LOTS of metal filings against the screen on the solenoid. I cleaned off the filings and put the new solenoid in. Drove the car while monitoring the codes. The cam "B" code popped up very quickly. I removed the new solenoid and there were a LOT of filings again. I pulled the intake solenoid and there were a LOT of filings on that one too (but no intake cam codes). Cleaned off both screens and reinstalled the solenoids. Drove the car again, same exhaust cam code. Pulled both solenoids, this time no filings.

Looks like the exhaust cam VVT is not working (or the cam position sensor is bad).

The filings must have come from the upper chain guide as it was being filed down.

Interesting that the intake cam solenoid had the same amount of filings but no error code.

I wonder if the filings got into the VVT exhaust sprocket and plugged it? Or maybe the passages in the head from the exhaust solenoid to the exhaust VVT sprocket are plugged?

I assume the oil goes from the solenoid through passages in the head to the cam bearing, and then through the cam into the VVT sprocket (how else would the oil get to a spinning sprocket)?

I ordered a new cam position sensor, solenoids, and a set of VVT sprockets just in case.

I have the factory service manual but there is no oil flow diagram in it. The next step would be to pull the exhaust cam and try to clear any passages in the head (and cam) that may be plugged.

Any thoughts?

Steve

Just as you said clean out time! Those filings can clog up the cam phaser. Ah, the fun of parts failure, this one ruined that one and it took out that one, oh joy!

Gee, generic titles of OBD2 tests are so helpful.:banana:

I thought I had written the actual code, but I didn't. The code I get now is "P0014 "B" Camshaft Position - Timing Over-Advanced or System Performance Bank 1"

Last night after work my son and I took everything apart again. This time I took the exhaust cam out. The passages were clear of any debris. The passages are also bigger than I thought and it would be hard to clog them. Also replaced the sprocket and cam phaser for the exhaust with a new one. Took the old one apart to look at the guts. It was also clean and has large internal passages that would be hard to plug. Then we blew out the passages in the head that lead from the solenoid to the cam. Those were clear also.

Put everything back together again. I was somewhat surprised to see the cam bearing surfaces ride directly on the aluminum head. No bearing inserts.

Just in case, we replaced the exhaust cam position sensor even though that was a long shot.

Put in a new exhaust cam VVT solenoid. Maybe the debris I saw previously damaged the first new solenoid I put in, even though we cleaned off the screen.

We could have finished the assembly and test drove it, but I forgot we need a new balancer bolt. I will pick one up today at the dealer and we will finish assembly.

I have replaced everything that could be faulty at this point. The only remaining possibility is electrical connections or the PCM (unlikely its the PCM as I have NEVER had a PCM fail on any vehicle). However, I am not getting any solenoid or cam position sensor error codes that indicate circuit problems.

I guess I will find out soon.

Steve

Sounds like you got it.


https://cimg7.ibsrv.net/gimg/www.che...13fbcead5.jpeg
This loose cheap EBay chain was related to a P0014, I changed the intake and exhaust solenoids and replaced the timing and balance shaft chains with Cloyes kits.


https://www.obd-codes.com/p0014

The stretched timing chain might have been the culprit or a solenoid stuck open

How can filings get to the solenoid valves without a busted oil filter?

https://cimg7.ibsrv.net/gimg/www.che...fd4e1bc6b.jpeg
Oil passage is prior to the solenoids and the oil filter

It would interesting to find out if those a plastic or aluminum. A magnet wouldn't help.

Rinse the swarf in solvent and look under a microscope. Bet even a 10x jeweler’s loupe would do. Some phone cameras will zoom pretty well, especially through a magnifying glass.