SLK 350 R171 Issues

[V8 Bob]

Looking at early SLK 350 circa 2004/05/06 invariably with mileage’s over 75k. Are there any specific trigger points that require major expense ie cam chain replacement, balance shaft etc? Would me useful to know relevant age/mileage and approx cost. Thanks in anticipation.

[Luke.]

Engines have problems. Fixed in the 2008 facelift.

[Monkeylegend]

There is a big thread over on MBUK club where you can check engine no's to see when the balancer shaft issue was sorted, but the early 3.5 litre engines up to maybe late 2006,early 2007, were affected.

Or maybe even late 2007 , early 2008. ^^^^

[RussJ]

Try SLKWorld.com for loads of info and advice...

[V8 Bob]

Looking at other forums suggests that 2004 models are less prone to balance shaft issues do you agree? thanks.

[RussJ]

Don't worry about the year as they often hung around before being registered, just check the engine number...

[Ian-27xza]

Agreed, you need to check the engine numbers.

The decision goes a bit like this:

1. Buy an early one - if the balance shaft issues raises it's ugly head it's about £2-2.5k at a good independent Mercedes specialist to get fixed properly. However, most are pre April 2006 so you pay less road tax.

2. Buy a later 171 phase 1 that doesn't have the affected engines. However, these are post April 2006 and attract £540 per year road tax.

3. Buy an even later 171 phase 2 with all the engine mods and 305 hp AND it's in a lower tax bracket.

So, if you're planning on running one as a 'keeper' then the above will need to factored into the man maths calculator!

I don't have any insight into the actual probability of the balance shaft failure.

[Funky Squirrel]

I have a 05 slk 350, it's a good car a couple of things to check. My engine doesn't have the cam issues but does have a warning for excessive oil consumption (not a problem yet in 90k miles).
Most of the underside is covered by plastic but the rear arches are vulnerable to rust
Auto box should have an oil change.
The electric seats move back to help get in and out if they are set wrong the seat back can hit the rear and damage the seat (magnesium seat are expensive to replace) the seat will rattle if damaged.
The bottom seat heater can be damaged by someone kneeling on the seat (back will still work).
On some cars a fuse box in the engine can get water damaged and corrode causing the Aircon to work intermittently.
Air scarf is a must if your enjoy year round topless action, some cars will have a perspex screen behind your head to stop wind buffeting this was a very expensive option and well worth it.

Above said they are great cars and all mine has needed over 8 years is a rear spring and a xenon unit.