SUBJECT:
3.5 L MPI – COLD ENGINE START-UP CHATTER
This bulletin provides information related to some 2011-2013MY Sorento (XMa) vehicles, equipped with the 3.5 L engine and produced from October 26, 2009 to July 14, 2012, which may exhibit a concern related to unusually loud engine chatter during initial start-up after sitting for several hours. To correct the condition described above, replace both intake CVVTs and camshafts with the new part numbers listed on pages 2 and 3. Prior to any repair, listen to the “before repair” and “after repair” sound files below to become familiar with the sound characteristics of the specific condition that this repair is intended to address. Confirm that the customer’s concern matches the one in the “before repair” sound file.
It is important to note that the 3.5 L MPI engine may briefly emit some timing chain/valve train chatter during start-up after sitting for several hours. Some amount of chatter (audible in the “after repair” sound file) is a normal characteristic of the engine’s design and the procedure in this bulletin is not intended to eliminate such noise; the repair procedure below is specifically designed to reduce unusually loud engine chatter as heard in the “before repair” sound file.
Before Repair
After Repair
Intake CVVT
| Old Design | New Design |
|---|---|
 |  |
| A = 1.85” (47.1 mm), | B = 1.46” (37.1 mm) |
Intake Camshaft (left)
| Old Design | New Design |
|---|---|
 |  |
| C = 1.54” (39.2 mm) | D = 1.15” (29.2 mm) |
Intake Camshaft (right)
| Old Design | New Design |
|---|---|
 |  |
| E = 1.51” (38.3 mm) | F = 1.11” (28.3 mm) |
CAUTION
When replacing camshafts, valve lash should be checked and adjusted if out of specification. Failure to do so may result in poor performance or engine damage.
PARTS INFORMATION:
Intake CVVT
| MODEL | PART NUMBER | |
|---|---|---|
| OLD | NEW | |
| Sorento (XMa) | 24350-3CAB0 24350-3C110 24350-3C112 | 24350-3C113
HYUNDAI Genuine 24350-3C113 CVVT Assembly
Last update on 2026-06-17 / Affiliate links / Images from Amazon Product Advertising API |
Intake Camshaft (left)
| MODEL | PART NUMBER | |
|---|---|---|
| OLD | NEW | |
| Sorento (XMa) | 24100-3CBE1 | 24100-3CBE2 |
Intake Camshaft (right)
| MODEL | PART NUMBER | |
|---|---|---|
| OLD | NEW | |
| Sorento (XMa) | 24900-3CBE1 | 24900-3CBE2 |
AFFECTED VEHICLE PRODUCTION RANGE:
| Model | Production Date Range |
|---|---|
| Sorento (XMa) | From October 26, 2009 to July 14, 2012 |
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Last update on 2026-05-24 / Affiliate links / Images from Amazon Product Advertising API
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The site keeps giving me an error on the Capcha code. Now I have yo start over again. In summary I would like to know if there is potential for damage caused by this problem with the 3.5L engine in my 2011 Hyundai. I have had the clatter for the last 30000 miles It was misdiagnosed as worn timing chain and guides. Repllaced and now it’s even louder on startup. All the same symptoms as described above by others. I have 236000 miles on an otherwise well maintained car but would not do an engine rebuild unless it was a recall. PLEASE describe potential consequences of this engine start up chatter issue. I had hoped Ed to get 300k miles. No other issues.
I have had this noise in my car for at least a year and a half. I took it to my Kia dealership and they could not tell me the problem.
Though the sound is embarrassing when around others, could anyone tell me if choosing not to replace these parts with the new models will cause any damage to my engine? My Sorento has 188,689 miles on it and I am not sure it would be worth what it will cost to repair these parts.
It’s been almost a year since I left a comment, I’ve changed the oil twice on my 2011 Kia Sorento and both times have added 1 qt of Lucas oil and the remainder with full synthetic oil. The cold start up rattle noise still occurs, so it appears adding some thicker Lucas oil does not fix the noise. The engine still runs fine after startup. Can you please explain why the thicker intake CVVT and the wider grooved intake camshaft explained above causes this noise sometimes and sometimes not? Other than the embarrassment of starting up the vehicle in front of others, will any harm be caused by not fixing this issue?
My 2011 Kia Sorento was sometimes making that before audio file chatter noise. Started around 60-70K miles. You should have seen the concerned look on the face of my mechanic friend when I asked him to listen. He suggested that I try adding Lucas oil stabilizer at next engine oil change. This is the oil that is thick like honey. I added 1 qt Lucas and 4 qts standard oil. The chatter noise was gone the first time I started the engine after adding Lucas. But the noise sometimes came back. It’s been several months since and the chatter noise occurs less often and is less severe when it makes noise. I can’t say yet that Lucas oil is a fix because there are variables like weather conditions, but it seems to help. I guess the thick oil does a better job of coating internal engine components?
Thicker oil gives you higher oil pressure, usually will help if you have an worn out engine, but the engine may not last long.
Is this a recall? I own a 2011 Kia Sadona and its making the exact noise in the above “before” audio file.
Will this be covered at the dealer as a recall considering parts had to be redesigned to fix the issue?
This is not a recall.