Is the rack the most likely culprit here, or are there other (simpler, cheaper) checks/replacements which should be done first?
And, has anyone else had the same problem?
Any advice will be appreciated.
Mondeo Mk4 Estate 2.2 Diesel, 08 plate.
The following symptoms appear when stationary or barely moving.
(1) When I start to turn the steering wheel left, there is a resistance. It clears with a slight knock as the steering wheel is turned further. If I stop turning (release the steering wheel) and resume, the resistance and knock occur again. This happens at any point throughout the steering (not just at neutral/straight ahead). When steering right there is no such resistance or knock.
(2) Whilst I am turning the steering wheel left, there is as much as half a turn immediately before full left lock where there is sluggishness or resistance, accompanied by increased wheeziness in the system (noticeably more than what you get when trying to turn past full lock). When turning right it is smooth right up until full lock.
(3) These are most noticeable when the car is cold. As it warms up, the knock and resistance diminish to almost nothing, but are still there.
The dealer said the steering rack was good. At the dealer's recommendation, the steering fluid and reservoir have been replaced. They reported the problem cleared on Thursday night, but on Friday morning when I collected the car, the problem was immediately apparent as still present, so I suspect they've been caught out by (3).
A forum search turned up a single reference to notchy steering in only one direction (http://www.talkford....ng/#entry881273) which might refer to a Mk2 (not clear). Other posts refer to notchiness in both directions and only when passing neutral/straight ahead. That post said that a steering rack replacement cured the problem.
As that's probably the most expensive fix, I want to ensure it's the correct one for me. I've also learned that the dealer's ability to correctly diagnose problems seems to be limited to following standard procedures with no independent thinking. They're fine if you can tell them exactly what's broken, and service is otherwise very good, but I don't want to spend money on unnecessary parts. This is Evans Halshaw Altrincham.
To me, resistance and sudden release suggest a sticking valve or piston somewhere in the hydraulics (either of which could of course be inside the rack). Being only in one direction suggests there could be two such valves or pistons and only one is sticking. As it happens only at or near stationary, I'd guess that maybe the valve is not completely closed (stuck) except at that time. But I'm only an analyst, not a car mechanic.