2003 VW Lt35 TDi Camper

[AlanJ46]

Problem.Develops a distinct 'hiss' when under load (2250 rpm on).Not detectable when stationary.No loss of power,fuel consumtion normal (25-27 mpg),oil consumption normal.Runs normally.No obvious hose leaks.Small crack in EGR pipe (replaced-made no difference).
Help required !!
AlanJ46

 

[mitzimad]

i would be looking for a leak on turbo pipework ,intercooler etc as its not present at tick over

 

[AlanJ46]

OK many thanks for the above-Will look at that aspect.In the abscene of visible damage must be some sort of pressure test??

 

[mitzimad]

soapy water?

 

[AlanJ46]

Nice one-I try.TVM

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[RS_rob]

Check the bolts on the Turbo & all the pipes that are under pressure i.e going from the turbo to the head, this will inter-cooler if fitted.

 

[AlanJ46]

Thanks for that.V. helpfull.What did you mean by '....this will inter-cooler if fitted.'?

 

[TheBig1]

it only takes a tiny rust hole or a perished rubber to allow pressure to hiss

 

[tacr2man]

Look for oil misting at any joins especially on intercooler seams , or at hose joints as a telltale .

 

[AlanJ46]

All very helpfull responses.Trouble is,getting at the pipes/hoses etc.Anyone tell me what is the first sign of trouble if not attended to?As I say vehicle runs fine (now).

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[pappajohn]

Thanks for that.V. helpfull.What did you mean by '....this will inter-cooler if fitted.'?

I think the word 'include' is missing.

 

[TheBig1]

that is the first sign and if not regularly maintained can start costing big money. If it is a leaking turbo, then they can fail catastrophically wrecking the engine. get it checked

 

[RS_rob]

Thanks for that.V. helpfull.What did you mean by '....this will inter-cooler if fitted.'?

Looking at some pictures it looks like your engine is cantered over to the left & if you look in from the left past the airbox to the back of your engine you will spot the turbo it is part of the exhaust system. Now it will either have a large rubber pipe going to the throttle body/head (non intercooled) or the pipe will feed to the front of the van into what looks like a small radiator this will be the intercooler then from the other side a pipe will feed to the throttle body/head.

Intercoolers are normally mounted so that fresh cold air can cool down the compressed gasses this then gives extra oomph.