Unburnt fuel?

[lacroupade]

Ladies - need your help again on two counts!

My tame mechanic has done some work on my newer truck which I've only had a couple of months, so still sorting teething problems. He's looked at two specific issues and I'd appreciate advice on both please....

1. I have noticed what I first thought was oil splattered on the tailgate, especially after my weekly fast 160-mile run from Oxford down to Dyfed. However, it evaporated after a while so its almost certainly diesel. He has confirmed there are no underbonnet leaks, so I can only assume its unburnt fuel coming out of the exhaust, possibly explaining why I get the same miserable 25mpg on this manual as my wifes automatic T2.

Any suggestions as to how I can rectify this and what might be causing it?

2. Since I got it in January there has been a mix of (really annoying!) very low frequency vibration/resonance underneath, usually as I pull away and again at around 60mph....mechanic believes it is almost certainly a cheap exhaust as he has seen this before....nothing loose underneath anywhere. I am happy to replace the whole thing if that will fix it and he suggested a stainless steel one, possibly bigger than the existing item.....any suggestions as to where I can get a reasonably priced one based on your experience, and the implications of going bigger bore (I think I'm right in saying that lack of back pressure doesnt have any implications for a diesel in the way it does for a petrol engine?)?

 

[lacroupade]

BTW - no white smoke accompanying, so personally I still think this fuel is coming from the engine bay and under the car (surely theres no way it could be coming from the exhaust in droplet form is there???) - it could be that all traces had evaporated by the time the mechanic checked, so maybe I need to give it a thrashing and check under the bonnet again....just like I do to the wife sometimes LOL.

Has anyone had any underbonnet fuel leaks and if so, whereabouts? (and don't say on a roundabout on the A329!)....

 

[zippy656]

BTW - no white smoke accompanying, so personally I still think this fuel is coming from the engine bay and under the car (surely theres no way it could be coming from the exhaust in droplet form is there???) - it could be that all traces had evaporated by the time the mechanic checked, so maybe I need to give it a thrashing and check under the bonnet again....just like I do to the wife sometimes LOL.

Has anyone had any underbonnet fuel leaks and if so, whereabouts? (and don't say on a roundabout on the A361!)....

heheheheh


well what else could i say

 

[lacroupade]

I take it thats the fastest road out of Swindon?! LOL

UPDATE on my exhaust question; spoke with a very knowledgeable and helpful chap from the local PowerFlow dealer - his advice was not to fit a s/s exhaust to these trucks.....his experience was that because s/s is relatively brittle, the additonal vibration that we all know and love causes the welds to crack and eventually break. Much better, he said, to get a decent aluminised system - cheaper as well.

So thats the end of that then....

 

[Paul]

diesel is a oil it will not evaporat, so it will not be that on your tail gate.:nenau

 

[Paul]

By the way is it hard to start when cold?

 

[lacroupade]

Paul whatever it is, it does sit there for a while....if I steam down to Wales on a Friday night the back door is spattered still on Sat morning but gone by the afternoon....jiust leaving a dirt mark, so can't imagine its coolant for example, but might be...haven't done the taste test yet!

Cold start is fine - just takes the glowplugs a while longer than the wifes to warm up....

Come the weekend I'll have to have a good rummage under the bonnet and see whats in evidence....

 

[Liam]

Paul whatever it is, it does sit there for a while....if I steam down to Wales on a Friday night the back door is spattered still on Sat morning but gone by the afternoon....jiust leaving a dirt mark, so can't imagine its coolant for example, but might be...haven't done the taste test yet!

Cold start is fine - just takes the glowplugs a while longer than the wifes to warm up....

Come the weekend I'll have to have a good rummage under the bonnet and see whats in evidence....

Paul
Just a thought and probably something you have already ruled out. Do you fill the tank before heading back to Wales? If so, check for slight leakage around the filler cap area or the rubber hose where it joins the fuel tank. It's possible that the rubber is perished allowing some small amount of fuel escape,especially if the tank is full.

 

[Paul]

Paul whatever it is, it does sit there for a while....if I steam down to Wales on a Friday night the back door is spattered still on Sat morning but gone by the afternoon....jiust leaving a dirt mark, so can't imagine its coolant for example, but might be...haven't done the taste test yet!

Cold start is fine - just takes the glowplugs a while longer than the wifes to warm up....

Come the weekend I'll have to have a good rummage under the bonnet and see whats in evidence....

May sound daft but if it's derv, you will still smell it, also put some on your finger and see if it feels oily, with it starting ok from cold says to me that it's not over fueling, as it would be hard to start.

 

[Toolbox]

Its not just water with soot in it is it?

 

[zippy656]

we get that, shows up then we got the caravan in tow.. just looks a bit grubby on the corner

 

[Paul]

Its not just water with soot in it is it?

Was thinking that, What took you so long to get here??

 

[zippy656]

Was thinking that, What took you so long to get here??

they got deep snow in Cornwall i think..
maybe he got stuck!

 

[Paul]

they got deep snow in Cornwall i think..
maybe he got stuck!

Not known Jeremy to get stuck yet..

 

[extreme-4x4]

my old vans use to have spots on the tail gates at times....

is the exhaust (exit end) inside damp oily or dry sooty both black obviously

 

[Toolbox]

they got deep snow in Cornwall i think..
maybe he got stuck!

No snow down this end of Cornwall, just sunshine.:naughty although it could do with being a little warmer.

 

[lacroupade]

Sooty water - mmmmm - will investigate, but I'm assuming that after 160 miles of foot-on-the-floor driving there wouldn't be any water in the exhaust surely? I wonder if its coming from under the bonnet somewhere though and only leaking when it gets hot? I feel an early bath coming on tomorrow, it being Friday, then its spanners out - I might even stick something up the exhaust pipe as Extreme suggests ...eeuuuwwww!

Thanks for all your pointers lads! :bow