How worried should I be?

[griffchris]

Nearly new self-build 420R with roller barrels, only had it back from PBC and IVA for a month.  Run in "hard but fair" on Millers competition running in oil x 2, with oil & filter changes at 20 miles, and again at 400 miles, now running on supplied Caterham synthetic 5w 50, 600 miles covered in total now.

I did my 1st trackday yesterday at Oulton Park, the car ran well (I am very much the weak link!), fully warmed up, water temp and oil pressure fine throughout, don't think I went above 7k RPM.

This morning, I started the engine from cold and, within a minute or two, noticed black liquid pooling on the floor under the exhaust pipe, doesn't particularly smell like oil (I don't tend to leave the car idling when cold).  I checked the oil level in the dry sump, looked OK, but the oil looks very black, was only changed just before the trackday (less than 200 miles ago).

I checked the spark plugs, all look quite sooty to me.  Coolant level is fine and looks clear (and pink!).

I did have an issue with a faulty ECU on 1st start prior to the PBC, and the ECU was changed by Caterham.  Not sure if relevant, but I did wonder whether the catalytic converter might have been damaged on the 1st start as it got very hot (glowing red) due to unburnt fuel igniting, but I guess it wouldn't have passed the IVA test if it wasn't working?  

Does the above suggest a problem (running rich? faulty lambda sensor??) or something potentially worse?  I shouldn't be getting carbon build up in the exhaust at this stage should I?

Can any old garage check this out, or do I need a Caterham specialist (I'm in Shrewsbury, so would be Kenricks or Oakmere)

Any advice gratefully received

Thanks

Chris

see photos below

/sites/default/files/images/users/12129/20160427_152334_resized.jpg

/sites/default/files/images/users/12129/20160427_152309_resized.jpg/sites/default/files/images/users/12129/20160427_152436_resized.jpg/sites/default/files/images/users/12129/20160427_154314_resized.jpg

[revilla]

You sure it's not just water from condensation / combustion with soot from the exhaust in it? Mind you, does look quite a lot of it. Does it continue to flow once you've warmed it up?

[TJG]

If it doesn't use excessive amounts of water or oil or continue once it's hot I wouldn't worry about it at all, looks very much like normal warm up condensation.

[Paul McKenzie]

Doesn't look good to me, so I'm not sure where your first stop would be with a self-build - Caterham or a third party?

And I don't know whether first job would be head-off and have a look (maybe Dave Brookes Competition Engines at Crewe) or the electronics (check the TPS and map at WGT at Middlewich with Pip Gardner)

But if it is third-party both are top men in those respective disciplines and Kenricks also are excellent

[Paul McKenzie]

Yes, as Revilla and TGJ said take it out and see what it's like warmed up first.  What's the orientation of the silencer tail pipe, by the way, it's not pointing slightly upwards is it and collecting condensation?

[Ivaan]

I would hope it's only condensation. It's been pretty cold / wet these past few nights, and if the car went into the garage hot, it would hold moisture.

If it still happens in the warmer / drier weather then it may need a bit more investigation.

Clive
 

[griffchris]

You sure it's not just water from condensation / combustion with soot from the exhaust in it? Mind you, does look quite a lot of it. Does it continue to flow once you've warmed it up?

Yes, I'm very much hoping it is soot rather than oil, the implications of it being oil would presumably be much worse.  I wiped a rag around the inside of the exhaust tip and there is certainly alot of soot there - but should I be seeing this after only 600 miles, particularly after a spirited run on track yesterday? - I've also been careful to avoid excessive idling, labouring etc whilst running it in. Should the plugs look like that after 600 miles?  Gentle "googling" suggests blackening of oil occurs very rapidly and this may not be a issue (though is mentioned more in respect of high mileage vehicles) - is this to be expected at this stage?

Since spotting the problem this morning, I haven't warmed the engine up so hard to know!

[griffchris]

Thanks all, replies thick and fast, I can't keep up!

I'll take her out and get her warmed up as soon as I get a chance, and report back.  The tail pipe is orientated downwards.  I do have a sneaky suspicion there might be some overfueling going on though, I committed the cardinal sin of running out of fuel on circuit yesterday, from a full tank, having covered no more than 60 to 70 miles  - do they all do that???

[Wrightpayne]

On a full tank 70 miles is about 7 to the gallon. I could only get my scooby into the high teens when really trying so think yours is overfueled. You need to be cautious as excess fuel can cause bore wash which removes any lubrication in the cylinders and makes everything wear faster.

You need some sort of assessment as to what is going on whether that be a rolling road session or plugged into an ecu reader.

Regards

Ian

[Wrightpayne]

On a full tank 70 miles is about 7 to the gallon. I could only get my scooby into the high teens when really trying so think yours is overfueled. You need to be cautious as excess fuel can cause bore wash which removes any lubrication in the cylinders and makes everything wear faster.

You need some sort of assessment as to what is going on whether that be a rolling road session or plugged into an ecu reader.

Regards

Ian

[Tomiam]

Hopefully it's not, but when my lambda failed that was one.of the symptoms. Lots of black soot coming out the exhaust.

If you have / can borrow a cable to plug into the ecu (available from sbd motorsport) that would tell you very clearly if it had failed via the free software (easimap).

 

[Tomiam]

Double post.

[Jonathan Kay]

Not sure if relevant, but I did wonder whether the catalytic converter might have been damaged on the 1st start as it got very hot (glowing red) due to unburnt fuel igniting...

How common is that in a road car? I thought that the references to afterburners were metaphorical, even in a 420R... :-)

What Ian says.

Have you still got the liquid? 

1. Pass it through filter paper and then test samples to see if they dissolve in water or in petrol.
2. Test if it ignites or burns. Usual precautions, especially about where you do this bit.

Jonathan

 

 

[John Vine]

From this distance, those plugs don't look too bad -- the central insulator is more white than black.  Can you post a close-up?

Re track MPG, I get 12-15 in my R400D (with RBs) -- but then, maybe I'm not trying hard enough!

Re diagnosis, I agree with Tomiam.  Logging sensor performance from a cold start for 15 minutes will quickly identify a lambda problem.  There are two members on the equipment-for-loan list with the MBE OBDII cable (Martyn and me).  I'm away shortly so can't help, I'm afraid, but you could ask Martyn.  Alternatively, you could invest in your own cable from SBD.  You need the MBE-MAP-KIT-3-CAN (MBE985) at £120 (ouch), plus the free Easimap software.  It'll probably repay its cost over the years.

All that soot (if it is indeed soot) suggests that you're over-fuelling.  That could be down to several things, including mapping, TPS setting and lambda.  The last two you can check with Easimap. (The first is locked by CC.)

Have you discussed this with CC?  If the car is still under warranty (I'm not sure about the implications of track use), they should be given the opportunity to investigate and advise.

JV

[griffchris]

Thanks for all the input.  I thought I should add the photo of the liquid in the glass is the engine oil, not the liquid from the exhaust.

 

For peace of mind, I'm going to take the easy option and take the car up to Kenricks to let them have a poke around, if any warranteable(?) work is required they might be able to undertake it, as an authorised caterham service agent, I'll liase with Caterham depending on what Kenricks find.

I'll report back.

Cheers

Chris

[revilla]

Ah! I misunderstood, I thought you had collected all of that from the exhaust which is why I said it did seem rather a lot! If it was just the splattering on the floor I still think the liquid is just condensation but the level of soot and the fuel consumption do suggest a possible fueling issue as described by other people.

[griffchris]

A brief interim update:

I took the car up to Kenricks yesterday, they phoned me this morning, though the phone line was poor so the conversation was brief:

It passed the emissions test therefore it is not currently overfueling, however they agree there is definite fuel contamination within the engine oil, and also excessive sooting of the exhaust etc, possibly indicating an intermittent overfueling problem?  I believe they have interrogated the ECU and failed to identify a problem.

Their current hypothesis is that there could be an intermittent lambda sensor fault, particularly in view of the excessive catalytic converter heating that occurred on the 1st start (faulty ECU with no spark to 2 cylinders which lead to copious unburnt fuel igniting in the cat), and plan to replace the lambda sensor, and obviously will need another oil and filter change.  Hopefully Caterham will at least cover the cost of the new lambda sensor.

Chris

[Nigel Riches]

Most ecu's reading lambda signals revert to a rich (safer) running program if the exhaust signal is lost. However the nasty black splatter looks more like cold engine start up condensation, if it still does it after a long run there is a problem, possibly a failed lambda sensor or wiring. 

Good luck sorting it out 

Nigel 

[griffchris]

Thanks Nigel, I think the principal ongoing concern now is the fuel contamination in the oil, would an intermittent sensor issue be enough to cause this level of contamination (and the rather excessive fuel usage)?

[aerobod - near CYYC]

If the car feels lethargic below half throttle and 4000 revs and consumes a lot of fuel when used in that area (worse than 20mpg / 15 litres/100km when the engine is warmed up), then it is likely a contaminated lambda sensor that needs replacing. If you can borrow or buy the MBE cable for your ECU, Easimap would diagnose this in a couple of minutes - with a warmed up engine the lambda value should oscillate every 2 or 3 seconds either side of 1.0 at lower revs and throttle opening, if the sensor has failed it likely will be in the 0.5 to 0.8 range continuously.