Jump to content
Do Not Sell My Personal Information


1.6 Tdci Wount Go... Wait It Goes! Nope, It Wount...


Carl0s
 Share

Recommended Posts

So, a while ago noticed this: When you brisky acceleration, between ~2000 and ~3000rpm you can clearly feel when the "pull" goes on and off. After ~3k you get nice and steady pull.

I encountered this first time whit the old engine, but didnt bother to give it any attention since i was changing the engine. But, now when it does it whit the new engine, il need to give it a closer eye.

First thing that came in to my mind, is that egr is stuck. When i turn the car off, i can hear the EGR doing the self test loop for few secs. And, ive been driving around the EGR disconnected for the las ~2000km and it did not have any effect.

If you accelerate gently, you wount notice anything out of ordinary, but if you accelerate briskly (like in overtaking) you can clearly feel it. Turbo should be fine, atleast i get steady 1.1bar boost during acceleration. :/

Any ideas ?

Link to comment
Share on other sites


Are you sure it is not just the mapping of the torque curve or do you mean it is almost juddering?

Link to comment
Share on other sites

The power out put feels like SIN wave. You can feel it climbing up, then at the peak it starts to decline, and then climbing again. its pretty steady, takes like 1sec to do the "cycle" (from the power to the no power, and back to power). So its not like "snap" power off, "snap" power on, but smooth gaining power - loosing power - gaining power, and after 3k you get steady pull.

If feels bit like when you have cracked boost pipe, it holds untill some point, when it starts to leak (the gaining power, and loosing power cycle) after the preasure drops, it starts to hold again, and regaining preasure. But, this sould be visible on the boost gauge? I get steady boost of 1.0 - 1.1 (tho, somethimes it bounces back and forth between 1.0 & 1.3). And, when i changed the engine, i checked the boost pipes (tho, just spinned them around in my hands and gave em quick view).

Link to comment
Share on other sites

had same symptoms on my 1.6 tdci. about 4 weeks later the bearings went- loads of play in them!! £1100 lighter now pal- not meaning to scare you but get it checked. pull the pipe off turbo at front and see if you can waggle the insides of the turbo? also check under engine cover and look at injecectors-should be no carbon mess or anything at all

good luck

Link to comment
Share on other sites

i also initally thought it was split hose etc, but nothing was split/cracked. was scratching my head- untill i got turbo noise!! then i shat myself lol

  • Like 1
Link to comment
Share on other sites


The engine was changed 2 weeks ago. Did the injectors too. Turbo had some radial play, but no axial.

EDIT: Hmm.. What kind of turbo noise? Since i can hear some "wshoooooooooooooooooh" sound during hard accelerations, that so far ive considered normal. (not much different what i heard on my mondeo, or what i can hear from my dads Kompressor MB...) :/

Link to comment
Share on other sites

sometimes odd squeal noise and had whooshing noises( i thought the wife was trying to describe the turbo whistle) hence why i though split boost pipe etc..then all of a sudden rattling noise in turbo area- then called AA

never had whoosing noises in the 1.5 yrs owned- and i have had all sort of turbo cars -so know what it should sound like when coming on boost :p

Link to comment
Share on other sites

Does this happen in all or some gears? is it worse in some gears than others?

Even though the boost appears to be "steady" the boost control systems (actuator, MAF, VNTmech etc ) goes up and down -

eg - you floor the throttle, more diesel gets sqirted into the engine, the turbine spins up, the compressor spins up, makes boost, higher boost pressure travels along the boost pipes, untill it reaches MAF sensor

Once the desired boost level is acheived (read by the MAF sensor) the ECU instructs the VNT to reduce boost -

This drops the boost pressure level coming out of the compressor, it then travels through the boost pipes/ intercooler untill it reaches the MAF sensor

Now, the MAF reads under the desired boost level, and the ECU instructs VNT mech to increase the boost,

The whole cycle goes round again, normally you are unaware of the (boost control) system doing its job, and it appears smooth

Sometimes, on a heavily modified car thats not set up right, you get this - its called "boost surge" "boost pumping" etc, a lot of it is to do with the delay between the compressor and boost sensor (MAF) the "pumping" can be at a high or low frequency

is it an electronic actuator? is it off the old or new engine?

Link to comment
Share on other sites

Does this happen in all or some gears? is it worse in some gears than others?

Even though the boost appears to be "steady" the boost control systems (actuator, MAF, VNTmech etc ) goes up and down -

eg - you floor the throttle, more diesel gets sqirted into the engine, the turbine spins up, the compressor spins up, makes boost, higher boost pressure travels along the boost pipes, untill it reaches MAF sensor

Once the desired boost level is acheived (read by the MAF sensor) the ECU instructs the VNT to reduce boost -

This drops the boost pressure level coming out of the compressor, it then travels through the boost pipes/ intercooler untill it reaches the MAF sensor

Now, the MAF reads under the desired boost level, and the ECU instructs VNT mech to increase the boost,

The whole cycle goes round again, normally you are unaware of the (boost control) system doing its job, and it appears smooth

Sometimes, on a heavily modified car thats not set up right, you get this - its called "boost surge" "boost pumping" etc, a lot of it is to do with the delay between the compressor and boost sensor (MAF) the "pumping" can be at a high or low frequency

is it an electronic actuator? is it off the old or new engine?

BOOST PUMPING!! Exacly the term i was looking before i tried to explaing the whole sin-wave thingy :)

The new engine was whitout any accessory, so only block, internals, head and intake. Everything else came from the old engine, and its the 66kw version, that has fixed vane turbo and a wastegate. The actuator for the wastegate is vacuum functioning, but the vacuum comes the vacuum pump via electronic controller. (what is hidden under the HP-pump on the back side of the engine)

I think its most notable when you are drivin whit ~2k rpm on 3rd or 4th, and nearly floor it (~80% of max).

The whoosing sound is similar what you hear, when you try to whistle whit dry lips, and you only hear the air movement :) (that was the closest thing that came to my mind)

I think i need to turn on the data-logging on my OBD adapter to get closer look of the boost preasure. Just incase the gauge it self has some lag and cant keep up whit the boost preasure change.

Link to comment
Share on other sites

How does the new engine differ from the old one - would the new engine have come with a VNT? is it the same CC etc

Im thinking the new engine is supplying more energy into the turbine?

is the electronic controller for the vaccum on the pumatic actuator connected/ working right

it may be possible to run the pnumatic actuator directly from the turbo (without the electronic part) the pnumatic actuator may be set to work at a set boost

Did you know with the fixed vane turbo you can fit a (seperate) adjustable electronic boost controller, so you could turn your boost up/ down as you drive?

Do you want more power or just want it running well/ reliable?

Link to comment
Share on other sites

How does the new engine differ from the old one - would the new engine have come with a VNT? is it the same CC etc

Im thinking the new engine is supplying more energy into the turbine?

is the electronic controller for the vaccum on the pumatic actuator connected/ working right

it may be possible to run the pnumatic actuator directly from the turbo (without the electronic part) the pnumatic actuator may be set to work at a set boost

Did you know with the fixed vane turbo you can fit a (seperate) adjustable electronic boost controller, so you could turn your boost up/ down as you drive?

Do you want more power or just want it running well/ reliable?

Its the same engine, 1.6 tdci 66kw version. Old one was -06 new one ~-09. All the numbers match... And ofc, the old one was 14 valve (valvetrain went haywire) ;) and the new engine is 290 000km less driven.

I could assume it works right. During engine braking boost drops to 0, during normal cruising its ~0,3 and when accelerating / driving up a hill its ~1.

Im not looking any extra power atm, just curious whats causing it, and how to possibly fix it. It doesent bother me that much, since you dont notice it on everyday driving. but it still bothers a bit :)

Link to comment
Share on other sites

  • 2 years later...

Hello!!

I know that this topic is more than 2 years old but since i have the same issue i thought i should write here.

I have the same engine (2009 1.6tdci 66kw wastegate turbo ).

My car does the same thing, mostly in 4th or 5th gear under heavy acceleration around 1.8k to 2.8k the boost fluctuates between 0.9bar and 1.3 bar.

To be precise, the car builts pressure up to 1.3 bar and then it drops to 0.9 to jump again up to 1.3bar and this happens for a while until it keeps steadily 1.1bar.

It seems as if the wastegate opens too late to relief the pressure and then opens too much!,

Egr is blocked so it is not a matter of egr.

As described from Carl0s if revs go higher than 3k the boost is steady.

Also if boost is reached to 1.1bar before revs reach 2k, then it remains steady.

Did anyone else other than Carl0s have this problem?

@Carlos, Did you find any solution about htis problem?

Thank you all in advance !!

Link to comment
Share on other sites

I had similar on my 1.6 tdci. It was worse in higher gears like 6 or 7th (it's a seven speed tiptronic ) From a steady cruise & wanting to speed up.

I Imedietly started looking at my egr

Disconnecting my egr made it worse ...

I ended up blanking it off & getting it mapped out.

Been free ever since

Link to comment
Share on other sites

Thank you for your reply.

As said above, i have an egr blanking plate, but the problem remains, so it is not an egr issue.

Did you block the egr and remap at the same time?

The remap was also turbo pressure increase?How much boost do you have now?

Thanks a lot , sorry for the too many questions!!

Link to comment
Share on other sites

Firstly I just blanked my egr off

This made my car unhappy in general

I then actually mapped my car for a best of both

Economy & power map.

I can't remember the figures of hand

But it's now 135hp from the original 109 hp

I get no less than 55 60 mpg

It's normally around 60.

Whilst remapping I deleted the egr all together from the map & took it off the car.

Only the blanking plate remains.

Whilst I was at it I had the dpf deleted also.

Link to comment
Share on other sites


  • 2 years later...

Hi. Did this ever get resolved?

Having same issue. No codes and car is egr delete and maf delete.

Anybody help please 

Link to comment
Share on other sites

Just had a thought.
I did clutch last week and left boost valve unplugged by mistake. Test drove and no boost obviously. Plugged back in and fine.
Point is even unplugged I had no light on dash?

Link to comment
Share on other sites

On 18/08/2017 at 2:50 PM, Juicehead99 said:

Point is even unplugged I had no light on dash?

 

On 18/08/2017 at 8:54 AM, Juicehead99 said:

car is egr delete and maf delete.

MAF delete sounds an odd thing to do. Knowing the air flow into the engine is very important, to avoid over-fuelling. Estimating the air flow from Inlet pressure (MAP), temperature (IAT),  & RPM is one way, but it depends on the exhaust backpressure (not measured), and engine condition, so is a bit approximate.

Usually no boost should give an underboost error, like P0299, so that suggests a bit of a problem with the engine or software.

Vacuum boost systems are rather crude, and a bit slow acting. Any stickiness in the mechanism will tend to give this hunting, or oscillating about the desired point.  Pressure and flow measurement problems will also make hunting more likely.

EGR valves will usually be closed under wide throttle conditions, so are unlikely to be linked to boost problems like this unless sticking open. But the MAF could be very important.

 

Link to comment
Share on other sites

MAF delete.

I had same issue on my old 2.0 307 and that was standard so I'm thinking not related.

If I build up the turbo mid revs before I hammer it its fine and flys,

I'm thinking overboost due to boost valve 

Or

Waste gate sticking open when it opens fast? Or fast enough to hit the open position with speed and stick there?

 

20170810_110234.jpg

Link to comment
Share on other sites

Leak on turbo you see is not anymore too just an FYI

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

 Share




×
×
  • Create New...

Forums


News


Membership