C70 t5 2.3t engine issues

[Mart5in]

Standard T5`s are still turbo ...Lol, and should be 98ron as per handbook.

95ron is for use just now and again and not continual use..........otherwise you get a big bill after so many thousands of miles.

I can't find anything in my handbook that says I should use 98 over 95. (or maybe I just skipped that page to look at more important things lol)

Anyways, 95 doesn't cause burnt valves any more than 98 would. burnt valves are down to running lean, incorrect ignition timing or using poor quality fuel - which can result in carbon buildup. fuels which lack lubrication can also burn your valves - that's not really an issue here though.

[960kg]

I can't find anything in my handbook that says I should use 98 over 95. (or maybe I just skipped that page to look at more important things lol)

Anyways, 95 doesn't cause burnt valves any more than 98 would. burnt valves are down to running lean, incorrect ignition timing or using poor quality fuel - which can result in carbon buildup. fuels which lack lubrication can also burn your valves - that's not really an issue here though.

You lot on here are so demeaning and do not lay yourself open to others learnings or findings or others opinions!

The thing is if you consider having things better to do than put the correct fuel in your motor than you yourself may be open to deserving burnt valves also.

95ron is dirtier than 98ron and will deposit the carbon around the neck of the valves affected ....the valve will then be restricted to opening properly which will give less clearance for the hot exhaust gasses and will burn the seat of the valve until part of it breaks off.....Nothing at all to do with a leaner mixture which can also cause burnt valves, this is another issue.

Also another issue is because one may be using the incorrect fuel for continuous running and of course it`s a turbo and the performance will be used then the ECU will retard the ignition because of poorer fuel and how does it do this?.......by the knock sensors bolted on the block.....and in between your more important things to do read post 16 and the malfunction of the knock sensors was probably caused by incorrect fuel being used and the knock sensors going overtime causing knock to continue.

Forgot to mention, have a look on your fuel tank cap and see if the sticker, if it hasn`t blown away by now, is still there and it will tell you what fuel is best to use!

I am not at all saying that this is the OP`s problem ...i was just trying to help another member see that using the recommended fuel on a turbo is the best way forward for reliability and performance.

[S70T5Chris]

Standard T5s can run on 95 quite happily.

Christ, that's like rocket fuel compared to the crap Americans run them on!

Remapped though, gotta be 98. I wouldn't even use BP's crappy 97.

That is incorrect. In Europe we measure our fuel ratings in RON, in the US it's MON (IIRC), which are not the same thing at all. And although the MON figures are lower than our RON numbers, it equates to the same octane fuel we have over here.

[S70T5Chris]

You lot on here are so demeaning and do not lay yourself open to others learnings or findings or others opinions!

The thing is if you consider having things better to do than put the correct fuel in your motor than you yourself may be open to deserving burnt valves also.

95ron is dirtier than 98ron and will deposit the carbon around the neck of the valves affected ....the valve will then be restricted to opening properly which will give less clearance for the hot exhaust gasses and will burn the seat of the valve until part of it breaks off.....Nothing at all to do with a leaner mixture which can also cause burnt valves, this is another issue.

Also another issue is because one may be using the incorrect fuel for continuous running and of course it`s a turbo and the performance will be used then the ECU will retard the ignition because of poorer fuel and how does it do this?.......by the knock sensors bolted on the block.....and in between your more important things to do read post 16 and the malfunction of the knock sensors was probably caused by incorrect fuel being used and the knock sensors going overtime causing knock to continue.

Forgot to mention, have a look on your fuel tank cap and see if the sticker, if it hasn`t blown away by now, is still there and it will tell you what fuel is best to use!

I am not at all saying that this is the OP`s problem ...i was just trying to help another member see that using the recommended fuel on a turbo is the best way forward for reliability and performance.

No one can argue with any of that. It's pure an simple fact.

It does amaze me how many people will use 95RON fuel (for the sake of saving a couple of quid on each fill up), and think that it is acceptable. I'm pretty certain it says on the inside of the fuel flap to use 98RON, even my ATR does!

I've said it for years, if you scrape on the little things, fuel type, tyres, which oil, which brake discs/pads.... what other aspects of your car are not up to scratch? You shouldn't be driving a 200+bhp car capable of 150+mph.

[Mart5in]

You lot on here are so demeaning and do not lay yourself open to others learnings or findings or others opinions!

The thing is if you consider having things better to do than put the correct fuel in your motor than you yourself may be open to deserving burnt valves also.

95ron is dirtier than 98ron and will deposit the carbon around the neck of the valves affected ....the valve will then be restricted to opening properly which will give less clearance for the hot exhaust gasses and will burn the seat of the valve until part of it breaks off.....Nothing at all to do with a leaner mixture which can also cause burnt valves, this is another issue.

Also another issue is because one may be using the incorrect fuel for continuous running and of course it`s a turbo and the performance will be used then the ECU will retard the ignition because of poorer fuel and how does it do this?.......by the knock sensors bolted on the block.....and in between your more important things to do read post 16 and the malfunction of the knock sensors was probably caused by incorrect fuel being used and the knock sensors going overtime causing knock to continue.

Forgot to mention, have a look on your fuel tank cap and see if the sticker, if it hasn`t blown away by now, is still there and it will tell you what fuel is best to use!

I am not at all saying that this is the OP`s problem ...i was just trying to help another member see that using the recommended fuel on a turbo is the best way forward for reliability and performance.

That's the answer I was looking for. just in case anyone shows 'ignorance' like my previous post.

Out of curiosity, I did look inside the filler flap and it doesn't actually mention RON ratings, only to use unleaded.

However in the handbook it does say that:
"98 RON is recommended for maximum effect and minimal fuel consumption."
"95 can be used when driving normally."


I always fill up with 98 (usually BP), it's only an extra fiver or so plus I've had mine remapped.

[Doingitsideways]

Ah, my bad.
Didn't realise the American system was different. Should have known better, as they refuse to comply with the rest of the world in any unit of measurememt, even their gallon is different to everyone else's!

I was merely saying that regular unleaded is considered fine by even the manufacturer (sure I remember reading that in the handbook somewhere) and I'd think it fine for pottering around in a standard T5.

Modified though, even with a simple remap, I wouldn't even consider anything below 98ron.

As for your Type R Chris, they're a highly strung, tuned version of a standard engine to start with, made to be revved to the redline all day long, so hardly surprising Honda reccomend a strong shot of juice to run them on
A standard T5 is such an unstressed unit, even though it is turbocharged, it could probably be ran on dog piss