Seized V8 turbo wastegate

[Winter]

I have just had a third instance of this, always the left hand side and the most recent 12 months/12,000 mile since a rebuild at Turbo Technics. With the cat off, can liberal application of penetrating oil plus judicial tapping with a hammer and attempts at movement via moles restore movement?

It's the bush that goes through the turbo body that seizes. The last replacement turned out to be a major job: shiny refurbished turbo accompanied by nearly every union being corroded.

In addition, one of the cats is on its way out. I followed a thread a couple of months or so ago on the relative merits of ceramic vs metallic - after I bought two ceramics from, I think, a reputable distributor (Autoparts, Mansfield area). Is there a problem with ceramics? I haven't fitted mine yet. The originals have done 80,000 miles in the car's seven-year life so I suppose they haven't done too badly.

Then there's the peppered front valance that needs painting and the rubber spoilers that are past their best. Oh, and the clutch is creaking. 46,000 miles since the last one so I suppose that's not too bad either.

However, not exactly a cheap time.

[neal]

The originals have done 80,000 miles in the car's seven-year life so I suppose they haven't done too badly.

That's probably a record!! Put cats on a serious car and they'll be toasted or blown away!

Mine lasted about 40k. Now both are completely hollow. But the hollow cat is a dream, sounds much better (better than the stock/standard exhaust) and plenty more bhp. That combined with straight through exhaust pipes makes a fabulous pulse-jet whine. I have a pair of normal cats for the MOT but they only see daylight for one day a year. The initial swap is a pain in the ass because everything's corroded and seized. Once past that, swapping them is relatively easy.

I mailed Brian Angus at Lotus about these:

Neal,

We are aware of the Cat problems

We are looking at the Catalysts at the same time.

We have spent a lot of time looking at the catalyst failures over the last

few years and the reasons for them.

Many of the catalyst failures were tracked down to engines having a misfire

that the owner did not realise was there.

Sometimes it was due to water in the plugwell(s) following work on the

sparkplugs and the gasket on the cover was defective or not fitted correctly

allowing water to leak into the cam cover..

Other failures were tracked down to overheating due to the engine being

'chipped' where the gas temperature was excessive or the fuelling incorrect.

Some brick failures were due to vibration where different mufflers had been

fitted to the car - this changes the vibration level / frequency on the

exhaust components.

Other failures were unexplained and may be down to manufacturing defects.

We have tested some of the aftermarket components but none of them met the

legal requirements for our certification. They would probably pass the MOT

requirements in Europe so are a good solution for some customers.

The Catalysts should last at least 80,000 miles if used on a standard

specification car. Our in test cars have completed these tests as required

by USA legislation.

Nearly every car we investigate has some kind of modification to either the

engine calibration or the exhaust / inlet system.

Minor changes to the fuelling or gasflow can generate major problems for the

catalyst.

The other thing that we find that reduces exhaust life is worn engine

mountings which increase / change the vibration levels.

We find many cars with the engine mountings incorrectly assembled - the

rubber snubber washers are usually fitted in the wrong place or fitted

upside down - this is another source of increased vibration.

Getting back to the original issue - we are looking into ways of making the

catalysts more robust so they may be able to withstand some of the in field

conditions they can see.

Cheers

Brian

The man's honest!! Mine's K&N air filters, straight thought exhaust, S350 ECM. So I'd expect the cats to get shreeded. And I did have a bad misfire until I changed the leads. Cats were already knackered but I doubt that would have helped!

Neal

[Winter]

Many thanks Neal.

New cats have perked things up a bit!