andreaslion43
T-Cross Engine Vibrates at Idle, Mounts Under Suspicion
Summary of the thread
A T-Cross with a 1.0 TSI engine experienced rough idling and vibrations, leading to a check engine light and error codes. The initial mechanic suggested replacing all engine mounts due to suspected wear, but past misdiagnoses prompted a search for alternative causes. Another user shared a similar experience where a faulty engine wiring harness connector, not the mounts, caused the issue. Following this advice, a second opinion revealed a loose connection in the wiring harness, resolving the problem for a fraction of the cost. This highlights the importance of thorough diagnostics, as electrical issues can mimic mechanical problems like worn mounts.
Did this summary help you solve your problem?
4 comment(s)
andreaslion43 (community.author)
Thanks for sharing your experience with the wiring harness. Did the repair cost hold up in the end? My T-Cross is showing those exact symptoms with rough idle and vibrations. The mounting bracket issue seems plausible since I can see some mount wear, but your electrical problem has me wondering if I should get that checked first. The mechanic quoted 750€ for replacing all rubber mounts. Have you had any recurring issues since fixing the harness?
ralfjohnson10
After resolving the wiring issue with my T-Roc, the repair turned out much cheaper than expected, just 95€ to fix a faulty connection in the harness. No rubber mount replacements were needed at all. The decision to check the electrical components first saved significant money compared to the quoted mount replacement costs. The vibration issues disappeared completely once the cable connection was properly secured. The mechanic found one motor mount showing early wear during inspection, but it was not the source of the rough idle problem. Since fixing the wiring connection, the car has run smoothly for 15000km with no recurring vibration issues or check engine lights. Would definitely recommend having the electrical connections thoroughly checked before agreeing to extensive mount replacement work. While mount failure can cause similar symptoms, the fix might be much simpler and less expensive. The transmission mount and other rubber mounts may eventually need replacement at higher mileage, but electrical issues can mimic mount problems. Getting a complete diagnostic check of both systems helps avoid unnecessary repairs.
andreaslion43 (community.author)
Following up on this whole experience, I ended up getting a second opinion from another shop who specializes in electrical diagnostics. Smart move, since they found a loose connection in the engine wiring harness near the intake manifold. The defective engine wiring was causing the vibration issues, not the mounting brackets. The total repair came to 180€, which included a full diagnostic scan and fixing the loose connection. Much better than the 750€ quote for engine mount replacements. The mechanic did note some normal wear on one motor mount but confirmed it wasnt causing the rough idle. Car has been running perfectly for the past month, no more vibrations at idle and the check engine light hasnt returned. Really glad I investigated further before authorizing the mount replacement. While mount wear is common at this mileage, its worth checking electrical components first when dealing with idle vibration problems. Lesson learned about getting a complete diagnosis before approving expensive repairs, especially when symptoms could have multiple causes. The original shop might have replaced parts unnecessarily if I hadnt sought that second opinion.
rmh_community_comment_box_header
community_crosslink_scanner_headline
community_crosslink_scanner_intro
community_crosslink_scanner_title
community_crosslink_scanner_price
community_crosslink_rmh_headline
community_crosslink_rmh_intro
community_crosslink_rmh_title
community_crosslink_rmh_subtitle
community_crosslink_rmh_brand
VW
community_crosslink_rmh_model
TCROSS
ralfjohnson10
The symptoms match what happened with my T-Roc 1.5 TSI at 98000km. The vibration issues started similarly at idle, and the check engine light triggered multiple error codes. A failed mount can certainly cause these symptoms, but in my case, the transmission mount was fine, the real culprit was a defective engine wiring harness connector. The vibrations occurred because the engine management system was receiving inconsistent signals. Before replacing any mounting bracket, have them check: Wiring harness connections around the engine, Spark plug connections and condition, Coil pack secure fitting, Vacuum lines for splits or disconnections The engine vibration can feel very similar whether caused by a mechanical mount issue or an electrical problem. However, a worn mount usually shows additional symptoms like clunking noises when shifting gears or visible rubber deterioration. This turned out to be a serious issue requiring the harness replacement, as continuing to drive risked damage to other components. Getting a second opinion focused specifically on electrical diagnostics would be worthwhile before approving mount replacements.