Did my timing belt slip or did I mess up the install?
An engine that idles fine briefly before running rough, dying, or refusing to rev past 2,000 rpm points directly to valve timing misalignment from the recent replacement rather than a slipped belt. This prevents the car from running reliably despite new components, as incorrect timing creates unburned fuel issues, strong petrol smells, and misfires.
What people tried
Every workaround mentioned in the threads below. We haven’t tested any of them — and nobody here is claiming they worked.
- 1removing the valve covers and timing cover to investigate
- 2Taking everything apart to inspect and reassemble the components
- 3Disconnecting the battery to reset the ECM to test for open-loop masking
- 4Replacing multiple fuel system components such as the high-pressure fuel pump, fuel rail, pressure sensor, injectors, low-pressure pump, and ignition coils
- 5Checking timing twice with locking tools
- 6Monitoring PIDs and sensor voltages using FORScan
- 7Tracing wiring looms for potential chafing or shorts
- 8manually rotating the crankshaft
- 9jumping the starter relay to crank the engine
- 10Checking timing alignment manually by rotating the crankshaft
- 11Jumping the starter relay to crank the engine and isolate the sound
- 12Performing a cylinder leakage test and setting the timing
- 13Disassembling the engine for head repair
In their words
Unedited, most upvoted first, each linked to the thread it came from.
“So it's a mystery. Did the timing belt somehow slip ? New tensioner, and I did the bleed procedure as instructed and remembered to remove the "grenade" pin. If it did slip, what did I do wrong, and why hasn't it happened again ?”source ↗
“I'm like 87% sure my 07 camry jumped timing, it's got a 2az-fe 2.4 l engine with 205897 miles. Compression reads 90 120 120 120 and 2 of the bolts for the ignition coils are stripped from the cover.”source ↗
“I’m trying to diagnose this metallic thumping/rattling engine noise on a 2014 Kia Sorento V6 3.3L and would really appreciate some advice from anyone more knowledgeable and mechanically experienced than I am.”source ↗
“Then, while driving on the highway, I suddenly felt what seemed like something gave away, immediately followed by a metallic rattling noise from the engine.”source ↗
“I found silver/aluminum-looking metallic flakes/shavings in the engine oil pan, which obviously concerns me.”source ↗
“I’m trying to diagnose this metallic thumping/rattling engine noise on a 2014 Kia Sorento V6 3.3L and would really appreciate some advice from anyone more knowledgeable and mechanically experienced than I am.”source ↗
“Then, while driving on the highway, I suddenly felt what seemed like something gave away, immediately followed by a metallic rattling noise from the engine.”source ↗
“I found silver/aluminum-looking metallic flakes/shavings in the engine oil pan, which obviously concerns me.”source ↗
“Since the swap it starts and runs, but: - Idles nicely for a few seconds, then gradually runs rough and dies. - Sometimes won’t rev past ~2,000 rpm. - Occasionally hits what feels like a hard limiter with a pop. - Strong petrol smell and a little white smoke.”source ↗
“At this point I’m wondering if I’m chasing a wiring, PCM, or control issue rather than another failed fuel component.”source ↗
“I’ve already swapped the HPFP, rail, FRPS, injectors, seals, LP pump and coils, so I’m running out of components to blame”source ↗
“i replaced the timing kit, but after i started havin cold start misfires and hunting idle and it sounds like this until i start driving, recently i started having the cold start rattles too, i have no error codes.”source ↗
“Little nervous pulling the head, the 2az is notorious for bolts stripping from the block.”source ↗
Where this came up
People with this problem also raised
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- 5Camshaft timing looks off by a tooth but engine ran fine
- 34Why does my car make a loud rattle when starting the engine?
- 2Cracked engine head while torquing oil pressure sensor
- 8Engine misfires and RPM surging when driving uphill
- 15Why are my oxygen sensor readings going crazy during a misfire?