AI Damage2018 Thor Motor Coach ACE: common problems
Owners of the 2018 Thor Motor Coach ACE filed 5 complaints with NHTSA, most often about electrical system and engine. The maker issued 1 service bulletins for this year. Details by component below, with sources.
Key figures
- Owner complaints
- 5
- Technical service bulletins (TSB)
- 1
What fails most often
- 1 Electrical system 20% of all complaints
- 2 Engine 20% of all complaints
- 3 Powertrain 20% of all complaints
- 4 Steering 20% of all complaints
- 5 Suspension 20% of all complaints
- 6 Visibility 20% of all complaints
- Electrical system: 1 complaints (20% of all).
- Engine: 1 complaints (20% of all).
- Powertrain: 1 complaints (20% of all).
- Steering: 1 complaints (20% of all).
- Suspension: 1 complaints (20% of all).
Symptoms owners describe
How many of the 5 NHTSA complaints mention each symptom (automatic count from complaint text; one complaint can mention several).
Components owners complain about
| Component | Owner complaints | involving a crash | Technical service bulletins (TSB) |
|---|---|---|---|
| Electrical system | 1 | 0 | 0 |
| Engine | 1 | 0 | 0 |
| Powertrain | 1 | 0 | 0 |
| Steering | 1 | 0 | 0 |
| Suspension | 1 | 0 | 0 |
| Visibility | 1 | 0 | 0 |
| Equipment | 0 | 0 | 1 |
What owners report
Short excerpts of NHTSA complaints in the original wording. These are owner statements not verified by NHTSA; personal data removed.
A mobile mechanic was called to the location and diagnosed that the front passengerâs side wheel bearing had failed and needed to be replaced. The mechanic stated that the wheel bearing failure was due to insufficient lubrication within the wheel bearing.
Tl* the contact owns a 2018 thor ace motor home. The contact stated that the windshield fluid sprayer did not spray the fluid high enough to clean the entire windshield. The failure caused a build-up of debris on the windshield.
While driving various speeds, the steering wheel was extremely loose, the auxiliary battery overheated, and the vehicle decelerated. In addition, the check engine warning indicator illuminated. Upon opening the hood, the contact noticed acid emerging from the auxiliary battery.
Underrated circuit breaker, 15 amp vice 20 amp, rating for rear air conditioner. Forward air conditioner, same model and size, has correct 20 amp circuit breaker. Overrated fuse d8, 20 amp vice 15 amp, on ceiling lights. This was found while stationary troubleshooting a water leak.
When owners complained
NHTSA complaints by filing year. The peak shows at what age the problems show up most.
Comparison
By complaint count this model year ranks 14,283 of 36,659 model years in the NHTSA data (top 39% most complained about).
On average one model year of the ACE has 3 complaints (13 years in the data). This year has 5, above average.
What to check before buying
- Electrical system. Scan all modules, test the battery and alternator, inspect connectors near the impact zone.
- Engine. Cold start, unusual noises, oil leaks and engine codes.
- Powertrain. Shift quality under load, harsh shifts, transmission codes, CV joints.
- Steering. Steering play, power assist, rack and tie rods after a wheel impact.
Manufacturer service bulletins
Bulletin titles as filed with NHTSA.
- This letter stated that there was one (1) Service Notification issued for the month of October, 2017
Other years of this model
Questions and answers
What are the most common problems with the 2018 Thor Motor Coach ACE?
Owner complaints to NHTSA most often mention: electrical system, engine, powertrain. Total complaints: 5. The most frequent symptoms in complaint texts: A/C or heater (20%), overheating, coolant loss (20%), warning lights, check engine (20%).
How many service bulletins (TSB) were issued for the 2018 Thor Motor Coach ACE?
NHTSA lists 1 manufacturer service bulletins for this year. A bulletin tells dealers how to diagnose or fix a known issue; it is not a recall.
Should I buy a 2018 Thor Motor Coach ACE from a US auction?
Owner complaints describe defects, not crash damage. Before bidding, check the components listed above and review the lot photos: VinWind builds a report of visible and hidden damage by VIN.
Other 2018 models
Read also
Sources: public NHTSA data (USA): service bulletins and owner complaints; YouTube: links to videos credited to their authors. Complaints are owner statements not verified by NHTSA, and describe defects rather than crash damage. Data updated 2026-11-06.