Exhaust v2.0

Today I got the car back from another shop. They re-did the exhaust tips for me. They weren't very nice about the quality of the previous tips which is understandable. There were some things about them I didn't like either. While they were at it, I had them take the catalytic converter off. I asked them to make an H pipe in its place and mount the lambda sensor in the crosspipe, but they said that was not optimal, it would have to be more of an X pipe for that purpose. That, on the other hand, would've been pretty expensive, so they ended up using the tip of the old cat. They said this results in a great flowing part that fits well with the surrounding pipes. I trust their judgement so that is how the exhaust was done.

General cat area as it stands now:

Complete exhaust:

I have to say, I'm especially happy with how the new tips turned out.

Removing the cat had a tremendous effect on exhaust sound. I had no idea the Mercedes catalytic converter muffled the sound this much. The exhaust is now pretty loud outside the car, and drones inside ever so slightly at 80kph. I would not dream about removing any more mufflers, it's perfect the way it is.

Here's a video of the new exhaust in action. No inside footage, sorry about that.

Mindless Trivia

I was bored to tears at home so I did some digging for some nuggets of trivia.

Did you know?

• When this car was new, in Finland it cost 1,1 million marks, or about 280 000 EUR, adjusted for inflation. In America the US model cost $145 000.
• There were a total of about 28 900 560 SECs produced, of which about 17 700 were facelift models, of which about 5000 were 1989 model year, and about 3000 were Euro models like mine. My car, therefore, is one out of about 3000 like it.
• There are about 285 560 SECs on the road in the UK, right now. That is across all model years and versions. Since the 90s, where the data starts, about 4% of 560 SECs have disappeared from the roads per year. Using that number as a basis for extrapolation, my car is currently 1 of about 9550 facelift 560 SECs left (1989-1991, US+EURO models).

Differential Woes

Ever since I first test drove the car, I knew the differential was going to be a serious achilles' heel. 5000km ago, on the test drive, it howled at 80kph like any Merc diff that had seen a lot of highway miles. Since I've been driving it, the howling hasn't gotten much worse, only it now happens on 85kph too. New to the situation, however, is a ticking (sometimes a crackle) coming from somewhere near the backseat. I started thinking oh-my-god, the diff is going to let go real soon.

I'd been waiting for fall in order to clean up the wheel lug thread grooves in the front. I figured since there is probably going to be a diff overhaul, and the car will be sitting for a while again, I'm going to do it now, and switch to Pentas/winters while I'm at it. This was last week.

Today I had an appointment at the shop. We opened the diff to start diagnosing the ticking. Well, first off, the diff wasn't dry. I'm not sure how much oil there was exactly but one thing was for sure, it looked pretty awful and it wasn't certain if it was the right kind. The diffs on 560's are pretty cranky about having just the right lubricant. After all, they are viscous LSD's, and Merc ones at that. I read a recommendation for Mobil HD 80W-90 hypoid oil but asked a buddy what he'd bought. He recommended LiquiMoly LS SAE 85W-90 oil which is for Limited Slip Diffs obviously. So that's what I got!

Old Diff Oil

New Diff Oil; LiquiMoly LS SAE 85W-90

I didn't take a very long test drive (road temp was 38C and I was running frictions) but the result is this. The diff feels like it howls a little less, but the ticking is still there.

While I was at the shop, an old taxi driver threw an interesting idea: what if it's a wheel bearing. Well, it certainly could be, and I started leaning in that direction initially, until I remembered something; the car only makes that ticking noise when cruising at 85 kph. If you let off the cas, it stops, and if you accelerate, it stops, even at the precise speed where the noise happens on steady gas. So I'm still thinking it's a bearing in the diff. Oh, and there was no evidence of metal in the old oil, or in the drain plug magnet. It's therefore pretty unlikely that anything else besides a bearing is damaged inside the diff.



Other than the diff problem, 560SEC ownership has been pretty mundane recently. I went to Lappeenranta Cruising a couple weeks back, for which I washed the thing and took the ten minutes to maintain the engine bay's cleanliness. Here's a pic I took while I was cleaning the lug threads.