Golf TDi problems?

[petescustompipes]

A friend of mines has a 110bhp golf re-maped to 155bhp. he bought the car from a work mate of mines so i know the history of the mods undertaken before my mate bought her. She was re-maped by torque tronics (the same man i got my 406 done by, very much so proffessional), a larger intercooler was instaled, the turbo was ment to have been sent to germany to be polished but came back dirty so chances are it wasnt touched, the inlet an outlet manifolds have been ground to increase volume and the usual lowerd sus and ss line.

The problem is when you give her a bit o stick she completly looses all power as if in limp mode and wont pick up again until stoped and started again. i take it that she is reseting the ecu and clearing the fault that is causeing the problem. Any help would be greatly appreciated thanks

[HDi fun]

What year is the Golf in question?

IIRC the 110bhp 1.9 TDi was the last 4 cylinder engine before the release of the PD unit injector range of engines.

I thinking along the lines of mass air flow sensor being the cause, but I'm not certain if the TDi 110 had one of these.

PGarner is the VAG man and he will quite possibly have the definitive answer straight from the bag.

[petescustompipes]

shes 00. airflow meter has been changed but the problem still arises. the same thing is happening to a number of 110hbp bora's and toledo's aswell, all re-maped to their full potentail. the golf however is the only one reaching 155 the rest are only managing around 130-140. different readings from different rr's.

[pgarner]

how much motorway driving does s/he do?

the PD engines have VNT turbos and its very common for the vanes to stick.
its a pretty easy fix from what i understand. remove turbo intake pipe and spray the vanes with WD40 and work the actuator until its moves free

[pgarner]

just had a thought the lower intercooler pipes connections are crap to say the least check these arnt loose and leaking the boost out

[petescustompipes]

as far as i know its nt a pd engine. does no motorway miles atall jus 5 miles back and forth from work evryday. al pipes and connections are fine no leaks no slits. the EGR valve is done away with if that counts for anything???

[HDi fun]

I think that's the problem. Short journeys wreck any car.

[petescustompipes]

yep short journeys dont do much good for the engine plus it dosent get much of a dog'in until a saturday night up castlegore but thing is the other cars are doing the same thing. there must be a fault in VAGs or the map or something. he was telling me last night that a seat leon is now doing it aswell.

[944]

my father has 97 golf 3 tdi 110 (or 115 im not sure) bhp aswell....its has intercooler and electric injection..smt similar is happening to it aswell...it looses allmost all boost at higher throttle somwere around 3/4 of the max...wturbo is not the problem we tested irt its working perfect...i think that the problem is air-flow sensor...HDI fun mentioned it before...and theese engines have air flow sensors...when i replace the sensors ill let u guys know what happend...

[944]

hey i got the car fixed!!!!!it turned that turbo eventualy was the problem..or one of them haha..it neded some cleaning and the other problem was the catalist(not sure i used the right word it reduces emitions of the engine)it was jamed...we removed it completly and the car is absolutly crazy!!!!!it goes even beter than before!!!!!!and sounds much better without a catalist!!!u stil can recognise its a diesel but its better than before...

[Poddy]

@ 944

If theres no CATs at all along the exhaust or the manifold, the turbo wont last long if its given dogs abuse all the time, i know a few people who fitted straight through exhausts to there TDI Vag's and all of them have had the turbos replaced after about 5-10k miles

[HDi fun]

Originally Posted by Poddy

@ 944

If theres no CATs at all along the exhaust or the manifold, the turbo wont last long if its given dogs abuse all the time, i know a few people who fitted straight through exhausts to there TDI Vag's and all of them have had the turbos replaced after about 5-10k miles

It's not the lack of a cat that's causing turbo failure - it's 5-10k miles worth of trashing that's doing it.

[Poddy]

the cars wern't thrashed for 5-10k miles

The Mechanic i go to to get my car tuned says it has something to do with the lack of back pressure in the exhaust which from what i understand isn't good for diesels

[HDi fun]

Originally Posted by Poddy

the cars wern't thrashed for 5-10k miles

The Mechanic i go to to get my car tuned says it has something to do with the lack of back pressure in the exhaust which from what i understand isn't good for diesels

]


How odd. Can't say I've come across that before. Which isn't to say he's wrong. I'm just puzzled how back pressure can be beneficial to any engine.

Any ideas?

[Poddy]

I'm not entirely sure on how the whole back pressure thing works with diesels, but i do remember him telling me that Turbo diesel with no CAT's or bends in the exhaust to create some sort of back pressue is bad for the turbo

[HDi fun]

Perhaps it's because a diesel engine has no throttle. Turbos are free spinning devices so there's no restriction in the intake manifold to 'brake' the turbine.

Maybe the back pressure stops the turbo from spinning up to outrageous rpms before the wastegate or geometry winds things in under electronic management? I am only guessing.

Then again, some turbochargers routinely spin at 250,000rpm under normal operating conditions.

It would be nice to get to the bottom of this and see whether it afflicts all turbocharged engines, only diesel ones, or only ones with/without variable geometry turbochargers.

[Poddy]

Mk 5 Golfs have VGT's don't they? I know the new Cee'd does but noone really buys a Kia to tune it lol (except me )

[pgarner]

yup they do

[HDi fun]

Apparently, the CR Kias tune very effectively indeed.

[Poddy]

My 1.6 CRDi was 90bhp standard, with just a remap it sits at about 140bhp with 300lbs ft of torque

[HDi fun]

300lbft from a 1.6 sounds a bit high. 300 Nm sounds more like it.

(Divide Nm by 1.35582 to convert to lbft)

[Poddy]

At the minute, my car has 125HBP and 230Lbs of torque which converts to 311Nm

[HDi fun]

That's about right. Not bad, is it? 230lbft from a 1.6 litre engine.

[Poddy]

thats the way my car is sitting at (at the minute)

in the next couple of months i'll be getting it retuned to increase the power/torque to 140bhp with 300Lbs of torque, when i get it done i'll post up a pic of the read out