My Cadillac STS 3.6 shows P0008 and P0009. Is it the timing chain?

Short answer: On the STS 3.6L V6, P0008, P0009 and related cam/crank correlation codes (the computer sees the camshafts and crankshaft out of step) usually mean stretched timing chains. Long oil change intervals make it worse. GM had special coverage on some years, but it has ended. The fix is replacing the chains, guides and tensioners.

Symptom: A check engine light; a rattle for a second or two on cold start; rough idle or slight loss of power; codes like P0008, P0009, P0016, P0017 or P0018.

What to check first

1. Read all codes. P0008 and P0009 point to the bank 1 and bank 2 timing, and P0016–P0018 to cam-crank correlation.
2. Check the oil level and condition. Low or old oil wears chains faster.
3. Have a shop check cam timing deviation with a scan tool to confirm the chains are stretched before replacing them.
4. Check that the codes are current after any repair, since owners found codes came back when the job wasn't complete.

Likely causes

1. Stretched timing chains. The usual cause on the 3.6L.
2. Worn guides or tensioners. Replaced with the chains.
3. Low or old oil. Speeds chain wear.

What it usually costs

An owner of a 2008 STS at about 123,000 miles was quoted about $2,500 by a dealer, and a CTS owner was quoted over $3,300 for the same engine. Prices are from owner posts.

Is it safe to keep driving?

Short trips, carefully. A stretched chain can jump a tooth or break and wreck the engine. Don't put it off long. Verify with a mechanic.

DIY or shop?

Shop for most owners. One owner did the chains himself, but it's a long job needing timing tools.

Recalls, bulletins and complaints in plain words

• Expired special coverage: GM published special coverage for timing chain wear on certain vehicles with the 3.6L V6, including some 2007–2009 STS (GM coverage document). Owners say this coverage has ended, but a dealer can check your VIN.
• Recalls: NHTSA lists no recall for the timing chain on the Cadillac STS in the model years we could check on 2026-10-23 (the recall lookup returned an error for 3 model-year queries). Check your VIN at nhtsa.gov/recalls. If your car is part of a recall, the dealer fixes it for free.
• NHTSA complaints: 11 keyword-matched complaints for Cadillac STS 2005–2011 (of 371 unique complaints queried, NHTSA complaints API by model year, queried 2026-10-23; keywords: timing chain, P0008, P0009, engine). This counts complaints that mention these words. It is not a defect finding.

What owners report

• In Timing replace for P0009 and P0018 DTCs on CadillacForum.com, a 2008 STS 3.6 owner at about 123,000 miles had P0008, P0009, P0018 and P0300; the dealer quoted about $2,500, and he replaced the chains himself but the codes persisted. A CTS owner in the thread had been quoted over $3,300 for P0008 and said GM's special coverage had ended.
• In Gen 1 V-6 timing chain replacement cost on the Cadillac Owners Forum, owners compared what the timing chain job costs on the first-generation 3.6 V6.

Quick tip

If your STS 3.6 throws these codes, have the cam timing checked before parts get thrown at it, and change the oil on time from then on.

Vehicle focus: 2005–2011 Cadillac STS with the 3.6L V6. The V8 Northstar models have different problems.

Safety / mechanic note

A failed timing chain can stall the engine and cause major damage. Verify with a mechanic.