2002 Cadillac DTS Problems: 1 Issues Every Owner Should Know
2002 model year · 0+ owner reports · Updated April 2026
According to Au7o's analysis of 0+ owner reports, the 2002 Cadillac DTS has 1 documented known issues, with 1 rated critical. The most serious is Northstar 4.6L Head Bolt Thread Pull/Head Gasket Failure ($2,000-$4,500 repair). Across all issues, repair costs range from $2,000 to $4,500. DIY maintenance guides at au7o.io.
All 1 Known Issues
On the 2000-2005 Cadillac DTS Northstar 4.6L, the Northstar 4.6L V8 in the DTS (and predecessor DeVille) has a well-documented design flaw where the aluminum block head bolt threads strip out, causing head gasket failure. The head gasket itself does not fail; instead the head bolts lose clamping force as the threads pull from the soft aluminum block. The problem is most severe on 1996-2003 engines. GM improved the bolt design in 2000 (longer bolts) and again in 2004 (coarser thread pitch). The Time-Sert thread repair is the accepted permanent fix.
Common Symptoms
- Unexplained coolant loss
- Overheating with no visible external leak
- White exhaust smoke (coolant burning)
- Oil contamination with coolant (milky residue)
- Exhaust gases in coolant reservoir (bubbling)
How to Fix
Confirm the failure with a block-combustion gas test, cooling-system pressure test, and by checking for repeated overheating/coolant loss with no external leak; on Northstar engines, a positive test usually indicates pulled head-bolt threads rather than a simple gasket defect. The permanent repair is to remove the powertrain, pull both cylinder heads, inspect for warpage/cracks, and install steel thread inserts in all head-bolt holes in the block (Time-Sert is the standard repair; some shops use NS300L/Big-Sert style kits on damaged holes), then reassemble with new head gaskets, new torque-to-yield head bolts, fresh coolant, and related seals. Simply replacing the head gaskets without inserting the block threads will usually fail again. Typical shop cost is about $3,500-$6,500 depending on engine condition and whether additional machine work, inserts, water pump, or crossover/case-half resealing is needed.
What Owners Are Using
Parts and tips from 0+ owners who fixed this issue
- UpgradeMulti-layer steel head gasket set for a reliable, long-lasting seal (Fel-Pro Head Gasket Set)
- UpgradeHigh-strength head studs provide even clamping force and prevent repeat failures (ARP Head Stud Kit)