Pinking

That's not enough - particularly given you're description of "thrashing" below!

Don't change up until you hit the rev limiter.

Take it onto the motorway. Accelerate as hard as possible in every gear, hold it at the rev limiter for a few moments before changing up. Then drive fast in 4th rather than fifth. Come off at the next junction and change direction. Repeat.

Yes if you insist on driving like a numpty!

You could also try pouring some decoke stuff down the plug holes before you do this - be prepared for lots of smoke!

Robert

Well, take it out of town then. I've watched your comments on this group and others, and it does seem that for your sake and your car's, you need to get out more.

First step - get some motorway lessons, so you don't c*ck the second step up. Second step - get some dual carriageway/motorway experience, to get used to driving at 70mph. This alone will do your engine some good - 70mph (real) may not be thrashing it, but it will be demanding a significant proportion of your 39bhp, so will do the relevant hot running. Run for at least an hour in these conditions - try driving to Bristol for a day/overnight trip. Or better, have a weekend walking in the Dales/Lakes (travel late to miss the queues, although at the moment nobody will be visiting as it's a bit wet :-) ).

clive

That's nothing like enough. You want to do what I'd call a week's worth of driving, 200 miles upwards, and thrash it properly.

I don't believe the top speed of your car is 22mph in first for one minute. There is a rev limiter and the car will hit it before it has a chance carry on revving until it breaks. The only way you can overcome the rev limiter is to change into second at 70 instead of fourth. Find out of the number of the Fiat owners club or something and ask them where it should kick in if you really believe you can rev your Sei past the limiter.

If you're just doing your normal 7 mile drive or whatever, but using lots of revs, you'll not generate enough heat to get rid of the carbon. You want to be cruising near top speed, or on twisty roads so you're doing lots of acelleration.

I've never coked up an engine, so I couldn't tell you. The previous owner might have changed up a couple of MPH higher than you do, leaving you with not much coking to do, if you see what I mean.

Just a spanner in the works if I may. How do you know that the engine is coked up? Petrol is cleaner these days and carbon deposit is not as common. Also what about large engine'd cars that never revs, or they would fly off the road? Yet you never hear about carbon deposit in those cars.

It's always driven very "gently", in high gears from what Peter says. Sounds exactly like my Mum's Polo which pinked horrifically until I had it for a week. The engines in big cars like Jags and BMWs etc. come with autoboxes, and when they don't the amount of torque available means you'd be trying pretty hard to labour one. I bet there's a correlation between motorway usage VS usage as a "town car" with car size too.

There aren't many other reasons for spontaneously developing pinking when the spark's good and the timing doesn't seem to be out. It's the most likely reason I can see, though obviously I don't *know* without having a look at the insides of the engine. If I wanted to go on I could argue that even after I've done that I don't know because it's impossible to know anything ;).

Sounds good but I'll need to wait until the end of term. I'm at University during the week and I work on the weekend. I don't have time to do this extra driving.

The manual has the top speed in kmph and it converts to about 22.1mph (it has short gearing). Somebody said that the redline would be before the rev limiter (and I shouldn't go past it).

Can't the pistons melt or something? We think that happened to our old Metro going up a hill, full throttle. It ended up with 2 dead cylinders.

No, most people wouldn't expect the car to be coked up after 33,000. I know the previous own used to go on the motorway and drive to London.

I said that the redline is generally before the rev limiter. I also said you shouldn't spend large amounts of time above the redline, but it's not going to destroy your engine on the spot if you spend some time above it. Even when you're thrashing it, you'd generally change up before the redline / limiter kicking in. So what you do is find out where the rev limiter is and then change up 5mph or so before it. The rev limiter will stop you breaking your engine, and it is there.

I'm about to beat you about the head with the clue stick here, so get a stiff drink and make sure you're sat down: Go to alt.autos.fiat, or your nearest FIAT dealer, or get hold of the FIAT owners club and find out where the limiter kicks in. The top speed of the car in first clearly isn't 22mph, as an indicated 26mph would mean a 20% speedo overread at the very least for the limiter to not kick in.

Maybe if you put 50 horses of nitrous into the inlet :P. I've never heard of anyone melting pistons in an engine that's in otherwise good nick without the aid of a lot of turbo / supercharger boost. Pinking on the other hand, can blast little bits off the pistons until they're knackered.

As I've said, I've no idea how long it takes to coke up an engine. From what I understand. if you manage to get incomplete combustion you'll get carbon knocking around in the engine. Incomplete combustion can be brought about by labouring the engine...

Ah, labouring the engine can cause it, the previous owner was a lady!

I'm sure there's a saying about people in glass houses somewhere...

clive

I seem to remember posts about it not pulling very well in fourth at 30 :).

What's that supposed to mean?

Oh, yeah. It isn't too bad though as long as the road's flat.

Guys, I think this *must* be a wind up!!

Robert

I really hope it is, but I've been driven by people in cars of similar power who go up the gears like they're in something with a 2litre engine and drive along with the engine spluttering like mad, so I can't rule it being serious out :P.

Google is your friend (searching for 'saying people in glass houses' worked for me - the best answer appeared in an idiom dictionary, 4th result for me).

clive

No, it's not a wind up. It's not just the engine that matters, it's the gearing etc. My engine definately doesn't splutter like mad! I've never driven a petrol engine bigger than a 1.3. It's actually pretty similar to the KA (1.3) that I used to drive (but slower). It's got short gearing and I do know how to drive!

I'll ask other Sei drivers to see what they do.

I've asked other Sei drivers and had some shocking replies. I think either 3rd or 4th can be used for 30mph altough somebody uses 5th gear with the 899cc. To be honest I wouldn't even try 5th at 30mph.

I'm very worried about all of them. Still, find out where the rev limiter kicks in. In the Ka the engine sounds like it's working a harder than I'd like at 30 on a level road in fourth.