[eye30]

Just this week while driving in 3rd gear when the revs get to 2,000 the engine seems to hesitate and appears to jerk. Upto and past 2,000 all is OK.

My turbo kicks in at around 1,500 so it's doesn't seem to be turbo related.

This does not happen in any other gear at 2,000.

Has anyone else had this or know what it could be?

[Shambles]

Yes I have. It's happened a few times when I've slowed down to turn a corner while leaving it in third, then it seems like the ECU is forced to raise the revs above 1000rpm when I complete the turn then apply the gas. The engine hesitates in the way you've described but always returns to normal after about 3 seconds.

I can reproduce this at will, and don't get bothered at all by it. I put it down to my lazy i30 driving and making use of the torque in 3rd, when I really ought to have been in 2nd.

[eye30]

Well at least it not just me.

I'm due to call in at dealers this week for 2nd remote so I'll mention and see what they say.
(Yes they have it at last!!!!!!!!!!!!!!!!!!)

[Dazzler]

Maybe it would be worth putting in an injector cleaner as Thumper has just done.. Just to see if that makes a difference (although if only in one gear probably unlikely)

[Shambles]

Not so sure Dazz.. Fergie has done this since I first "took her out".

Picture the scenario (dunno whether it's the same as eye30's scenario)... Approaching a turn, slow down, leave in 3rd, take the turn, straighten up, leave in 3rd, let the torqaue and ECU speed her up, then press the pedal. Fergie decides that a humping is in order and stutters for a couple of seconds, almost as if air intake is the problem. Then she gasps and continues as normal, in 3rd.

It sure doesn't bother me, to be honest. Then again, if eye30's experience is different......

[Thumper]

Mine has done this since new, and I can recreate the event every time, every day now.

(Fuel cleaner has done nothing to fix the issue, nor fitting the original exhaust. Did the same thing before the exhaust was changed)

When I leave home, no boost, taking it very easy, change gear each time at 1,500rpm......I get to one roundabout, turning right, accelerate in third to 1,500rpm no boost, hit fourth, 1,200rpm onwards, 1,500rpm it starts to boost and pull very strongly to 1,800rpm where it just splutters, comes off boost, throttle is held in the same position, no more acceleration, just a constant rpm (around 1,900rpm now)

I push the accelerator down some more, boost comes back (But it feels like only 50%) go up to 2,200rpm, change to 5th gear, comes on boost strongly all the way up to 110km/h

This is repeated every morning. Only started to notice it getting worse as the weather turned colder.

Yesterday morning, -5 degrees C, I had to use almost 3/4 throttle to get any form of acceleration after it spluttered in 4th gear. Change to 5th gear, 1/4 is all that was required to maintain the same acceleration. (Temp probes showed 2 degrees C entering the intercooler, -1 degrees C exiting the intercooler.)

Until I hook up a boost gauge, I believe, in what it feels like, the engine is coming on boost down low, but creates too much boost, too low, it then either changes the fuel timing and/or fuel rate to control this boost spike.

It almost feels like the ECU is limiting boost pressure/fuel delivery because of a boost spike.

This only happens once, per drive. (Normally just after a cold start)

Thoughts anyone?

(Oh yeah, I've had the dreaded 3,000rpm drop off three times before when it was warm. Since winter blend diesel has been used, I haven't had any problems)

Have any of you that have experienced these issues got acces to an OBDII device that can read error codes?  Just wondering if any abnormalities are being reported to the ECU about these events.

Interestingly, I have not had the issues many mention, although I did have the 2900rpm issue which has beeen well documented.  This was fixed with a fuel filter unit replacement.  I must say though that I do change up at just under 2000rpm, not at 1500rpm.  I have noted, since I have had the Scanguage II, that fuel economy in each gear improves slightly as you approach 2000rpm and then starts to go up.  This is why I change up at this rpm.  

Also, I can watch the MAP (Manifod Boost Pressure) as I drive and I do not detect significant boost in the rev range below 1900rpm.  There is some, but it is not dramatic.  I think it may be dependant on the throttle opening.  What I am saying is, go easy on the throttle in the <1900 rpm and the boost is minimal.  That is what the MAP is reporting anyway.  Today I drove with a MAP in the range of 15psi to 16psi for the majofity of the 150km I do in a daily basis to and from work.  14.6psi is the reading with the engine not running at all.

Bob

[Thumper]

Bob, looks like I will have to purchase a Scanguage to see what is going on.  

[eye30]

if eye30's experience is different......

Yes it's different.

It seems as though at 2,000revs there is a flat spot.

All other gears there is no problem. Take up is smooth, no hesitation no flat spots.

[dwalton]

Eye30,

Did you ever get to the bottom of this issue, it sound that exact same as what I am having.  ECU shows no issues so dealers dont do anything

Regards,
Dale

[eye30]

Yes I got an explanation from the Dealer.

I posted it here as part of another posting:
viewtopic.php?f=6&t=747&p=6030&hilit=2000+revs#p6030

I've repeated below:
Called in dealers and they indicated that what I was experiencing was Turbo lag..

This is only noticable in 3rd as in there words - 3rd is a half way gear and can be sensitive to small changes in revs and at 2000revs the turbo is just on the edge of kicking in.
Whereas in other gears the engine speed is increasing at speed and turbo lag is not as noticable as the revs pass thro' 2000 revs in a "flash".

[dwalton]

Thanks, did they give you a solution to this? or is it just a case up put up with it.

Dale

[eye30]

Thanks, did they give you a solution to this? or is it just a case up put up with it.

Dale

No.

Car due in late Sept for 1st year service so they asked me to monitor and if still a problem will check it over then.

Overall, not a big prpblen just noticable 1 in 1000+ gear changes.

[Lakes]

know this is getting old, but read doze post in modifications as, i felt that jurk you describe when car was new, i think it was the way i was driving at the time, but i thought to myself thats caused by the turbo not having a waist gate or not opening the waiste gate, at that time i knew nothing about what turbo the motor used, i still know nothing about turbo's and don't really want to learn, but thought i'd mention that as drove a car only that was a tunned up turbo it had that same jurk but much more violent the onlt the i30 had was very soft mild one but i noticed it. would not call it a flat spot ( more like small tits)

Lakes wrote:

the i30 had was very soft mild one but i noticed it. would not call it a flat spot ( more like small tits)

Interesting simile Lakes.  Never thought of it like that.

I've experienced the symptom, but only when the engine is cold.  I find if I change down and let the revs take the engine past the problem area and then change up, all is fine.  I have had it happen in 4th also (when cold).

Like Lakes said, it is a matter of changing your driving habits.

Bob

[Thumper]

Also, I can watch the MAP (Manifod Boost Pressure) as I drive and I do not detect significant boost in the rev range below 1900rpm.  There is some, but it is not dramatic.  I think it may be dependant on the throttle opening.  What I am saying is, go easy on the throttle in the <1900 rpm and the boost is minimal.  That is what the MAP is reporting anyway.  Today I drove with a MAP in the range of 15psi to 16psi for the majofity of the 150km I do in a daily basis to and from work.  14.6psi is the reading with the engine not running at all.

Bob

Bob, interesting. Since I've hooked up my Scanguage, I have tested over several days now, with several changes to the vehicle (Free flowing exhaust, stock factory exhaust, intercooler cover in place, no cover as per factory stock)

What I see is a sudden increase of boost (base level in the morning is 14.8) from 1,600rpm up to 1,900rpm, I will see 34.9 psi indicated (20.1 psi actual) as soon at it hits 1,950rpm in third gear, boost suddenly drops down to 19.2 psi indicated (4.4 psi actual) where I can hold 4.4 psi all the way to 4,000rpm (Foot flat to the floor)

As soon as I change to 4th gear, boost will rocket back up to normal, 28.4 psi (13.6 psi actual)

How can this be turbo lag when I am already boosting?  

No error codes show up.

This can be repeated by myself and the wife, with the free flowing exhaust, or the the stock system.

Though, interesting to note, I can eliminate this altogether when the intercooler cover is fitted, with an inlet air temp above 20 degrees C.

I notice the 'over boost' when it's cold and the intake temp is below 10 degrees C.

Food for thought.

[mobilegps]

hi guys,

i am new and had been reading your posts. 

is this i30 problem same like the one in Kia Ceed ?

http://www.kia-forums.com/kia-ceed-forum/40997-crdi-engine-hiccup.html

[Lakes]

Hi, not sure about the kia? but same motor i think, just i have not had it happen, its hot here right now and i think the motor likes the heat.

[TheBunyip]

Hi all,

Anyone still having this problem MIGHT find what follows of some use.

This post is a case of sticking my neck out again when even I know that I have no idea what I am talking about.

I came back to this thread after reading about MAF problems on another site.

Now if the i30 CRDi ECU (and Kia Ceed) uses data from the MAF sensor to adjusts fuelling and not just the EGR system the problem might, just possibly, have something to do with the output from a MAF sensor or the way the ECU is set up to interpret the upper readings.

Try these two links about Rover/BMW diesel MAF problems and see what you think...
http://tuning-diesels.com/Mafam/MAFQAS.htm
http://tuning-diesels.com/75Zt/R75maf.htm


These links might provide something useful. On the other hand anyone with access to a full workshop manual or indeed a good diesel engine tech might be able to tell me if this is so much rubbish. Of course I have no idea what MAF sensor, if any, is used in the i30 CRDi.

[Shambles]

Well, thanks Bunyip. Not only do I now know what a MAF is, and where it is likely to be located, but I now have an idea what might have been causing my MGZR to be so poor at low revs and not revving to the red line.

Eye30 - are you still having this "might be turbo lag" problem? One of the recommendations in the links Bunyip provided is to disconnect the MAF sensor (seems to sit somewhere along the air intake tube) and see if the problem remains at low revs.

[eye30]

Eye30 - are you still having this "might be turbo lag" problem? One of the recommendations in the links Bunyip provided is to disconnect the MAF sensor (seems to sit somewhere along the air intake tube) and see if the problem remains at low revs.

No problem now.

I mentioned this at the service in September and lo and behold it hasn't reappeared.  I think they twecked the settings.

So for now I'm following the old saying "If it ain't broke don't mess with it"

Thanks Bunyip for researching this issue.