Hot idle issue - R400D

[moorsd123]

Thanks Eriedor, that's interesting and sounds like what I'm experiencing. I am starting to think this may be an inlet leak somewhere as it only happens when the car is hot, so maybe opening a crack or gasket leak when things expand? Was yours a Duratec with Aluminium plenum?

Does anyone know the best way to check for leaks on the inlet side? I've checked visualy and can see anything obvious.

[John Vine]

4 hours ago, moorsd123 said:

Thanks Eriedor, that's interesting and sounds like what I'm experiencing. I am starting to think this may be an inlet leak somewhere as it only happens when the car is hot, so maybe opening a crack or gasket leak when things expand? Was yours a Duratec with Aluminium plenum?

Does anyone know the best way to check for leaks on the inlet side? I've checked visualy and can see anything obvious.

I'm also beginning to think that an air leak is a contributory factor here. Do you have the aluminium plenum? They are well known for developing hairline cracks. The cure in my case was to upgrade to roller barrels.

JV

[moorsd123]

Haha John...we are on the same wave length!! Already got a quote from Northampton Motorsport (for Jenveys), and is a more valid reason to explain to the Mrs why I need to spend £5k, rather than just "upgrade itis" 🤣

It is the aluminium  type. I've heard about spraying Ezi-start around the plenum which will increase the revs if there is a crack/leak, so may try that?

If it is a crack it is likely to only be opening sufficiently enough to cause the issue when it gets hot, so not sure if I should spray the Ezi-start when hot or cold...don't want to risk setting the car on fire if there is a potential risk of that?? 😬

 

[Eriedor]

It was a long time ago for me, if I remember rightly I sprayed a little carb cleaner around the intake manifold and the revs immediately responded, confirming the issue that my gasket was lunched!

[Jonathan Kay]

On 29/06/2024 at 11:06, moorsd123 said:

I've heard about spraying Ezi-start around the plenum which will increase the revs if there is a crack/leak, so may try that?

If it is a crack it is likely to only be opening sufficiently enough to cause the issue when it gets hot, so not sure if I should spray the Ezi-start when hot or cold...don't want to risk setting the car on fire if there is a potential risk of that??

5 hours ago, Eriedor said:

It was a long time ago for me, if I remember rightly I sprayed a little carb cleaner around the intake manifold and the revs immediately responded, confirming the issue that my gasket was lunched!

There are various different active ingredient in starting sprays including diethyl ether, volatile alkanes and acetone. Carb (and brake) cleaner typically contains acetone.

If there's any plastic in the manifold or nearby I'd use as little acetone as possible. 

Any of these could conceivably ignite as that's their purpose in life, but the risk isn't great with a short burst of spray. And of course you have an appropriate extinguisher to hand...

Jonathan

[John Vine]

On 29/06/2024 at 11:06, moorsd123 said:

Haha John...we are on the same wave length!! Already got a quote from Northampton Motorsport (for Jenveys), and is a more valid reason to explain to the Mrs why I need to spend £5k, rather than just "upgrade itis" 🤣

It is the aluminium  type. I've heard about spraying Ezi-start around the plenum which will increase the revs if there is a crack/leak, so may try that?

If it is a crack it is likely to only be opening sufficiently enough to cause the issue when it gets hot, so not sure if I should spray the Ezi-start when hot or cold...don't want to risk setting the car on fire if there is a potential risk of that?? 😬

 

Or you could go the RB  route and avoid the need for a new ECU.

JV

[moorsd123]

That is an option John, but the cost works out similar and I won't have the advantage of a carbon airbox (to keep the noise down on track days) and a custom map for the car.

I do like the idea of a genuine Caterham Upgrade though? Do they just flash a new map to the existing ECU then?

[John Vine]

1 hour ago, moorsd123 said:

That is an option John, but the cost works out similar and I won't have the advantage of a carbon airbox (to keep the noise down on track days) and a custom map for the car.

I do like the idea of a genuine Caterham Upgrade though? Do they just flash a new map to the existing ECU then?

RBs need a cut-out in the bonnet to accommodate the filter.  When CC fitted mine, they cut a hole large enough to take a carbon airbox (which I didn't need so didn't pursue):

As for the map, yes they flash a new one onto the existing ECU.  Some folks can be a bit critical of the generic CC maps, but I find mine seems to match the car very well.  An RR session with someone like Steve Greenald always remains an option if you're seeking a perfect map.  (For info, Steve developed the generic RB map for CC.)

I've just looked at the RB kit price on CC Parts: a stonking £4.9K!  Ouch. In 2014, the kit (incl fitting) cost under £2K.  That's inflation for you.

JV

[ScottR400D]

've just looked at the RB kit price on CC Parts: a stonking £4.9K!  Ouch. In 2014, the kit (incl fitting) cost under £2K.  That's inflation for you.

Well, it’s CC inflation for you, not genuine inflation. 

Do they actually still stock and fit these things anyway now they’re a ‘manufacturer based business’…….

[moorsd123]

I think it's directed via a dealer now (every time Ive looked Caterham have been "out of stock"), and the upgrade kit on Oakmere's website mentioned once ordered from them, the upgrade will take place at their Gatwick service centre?

May be why the price has gone up so much...two profit margins in the mix now?

Edited July 1 by moorsd123