Independent Renault Forums banner

2.2dci - low power in low rpm

16K views 18 replies 5 participants last post by  ikwj 
#1 ·
Hi there,

A problem has arisen in my Espace in the last few days. When accelerating away from rest, it's very sluggish - it takes 2-3 seconds for the turbo to kick in and accelerate away.

Once in the higher gears, it's not exactly a rocket ship, but runs ok.

I put it down to the air con running.

My wife was out this morning, and it took 30 seconds for the turbo to kick in...she was stuck bumbling along just above idle for an eternity. No warnings on the dash, and ran fine (but sluggish to pull away) after that.

I took it for a test run tonight, and can confirm the sluggish pulling away. It takes 2-3 seconds for the turbo to kick in and for acceleration to start.

There is a small amount of oil accumulated on the top of the engine (see pics), and a full throttle acceleration can get noisy. Will still touch 160kph though, so outright power doesn't seem too affected, and there's no smoke out the back (some is noticable in following headlights at night though).

What's going on? I recon it's one of the following:
- Dirty air filter + EGR combo
- Auto box being a problem; it has a known issue of "clunking" into first.
- Turbo on the way out

Difficult to compare it to the past - I bought it at 50k miles, and now it's done 62k.
 

Attachments

See less See more
2
#3 ·
This sounds plausible. However, the turbo does actually kick in - it just takes a few seconds, and does seem to be higher in the revs. Would this fit this scenario?

And just to read that right...its three components:
- airflow meter
- vacuum pipe to boost solenoid
- boost sensor on intake
 
#5 ·
Thanks Mickey - can I assume that these *are* vacuum operated then?

Took it for a run this evening, and it's strange - pulling away from some junctions, it's totally normal - lunges off the line with only a modest use of the accelerator. Next junction - it just pulls away slow as anything, even with foot to the floor...then "whoosh!" the turbo kicks in. The time it takes for the "whoosh!" to arrive varies too.

And then it'll accelerate normally for another junction or two.

Give it the beans, and it stomps along normally - I not had a chance to try some motorway.

No warnings or anything. No smoke out the back. MPG for this tank is 12l/100 (normally about 10l/100 for mostly town driving...in hilly Switzerland), but I have been booting it, to try and decoke the EGR.

It's going into Renault on Thursday to read the errors log, and if the errors are "inconclusive" I might ask them to replace the air filter, then clean the EGR. Then take it from there.

Very strange.
 
#6 ·
As mickeybo says these do indeed boost from idle as do most modern turbos you should not feel them KICK IN it is vacum that closes the wastegate to create boost and if you have a vac leak it will missbehave


Also worth noting a diagnostic will not pinpoint the cause but will give you fault codes for low boost as the boost is low !! it will also give you airflow faults for the same reason these faults need cleared then retried on a road test to se what comes back

The low boost is a symptom of the problem dont let them tell you the turbos stuffed unless they have done vac tests and leakback tests on injectors and got good fuel pressure readings first

There is also the possibility the manifold gaskets are leaking causing the loss of boost

As you see there are lots of maybes you need someone who knows the engines weaknesses
 
#12 · (Edited)
Hi I had the same problem on my Mk4 espace which was getting progessively worse taking upto 15 to 20 seconds for the turbo to kick in then running fine until the next junction. Makes for hairy driving at junctions and roundabouts. Cleaned the EGR valve no difference, blanked of the egr valve with a plate no noticeable difference. Read on one of the threads about MAF valve. I unplugged the lead going to the MAF (located just after the airfilter on the right hand side of the engine compartment) car now runs like a rocket from the word go. Will get round to cleaning the MAF with some IPA spray at the weekend or maybe replace it. Hope this helps someone else and thanks for the tip where ever I read it.
 
#15 ·
Hi Madnoel I have not checked for cracked or leaking inlet manifold problem but will do so. However, I would have thought that if it was a manifold problem that disconnecting the MAF would have no effect as the air leak would still be there unless the ECU working in default mode adjusts for that? Will hopefully let you know after the weekend.:d
 
#14 ·
Yep MAF for me too! Disconnected the cable and it was back to 90% normal!

The sensor was kaput so had to fork for a new one us fitting. Cleaned EGR valve at the same time. 900 chf cost, but it's back to normal - and initial indications are it has improved economy too.

Sent from my GT-N7000 using Tapatalk 2
 
#16 ·
The MAF measures the volume of air being taken into the inlet system and the ECU adjusts the amount of fuel based on this. If there is a leak beyond the MAF then what is actually going into the engine doesn't match what the MAF measures. Once the MAF is disconnected and the ECU goes into default the ECU then assumes a notional amount of air will be ingested - this is based on the engine rpm.
 
#17 ·
Ok latest update. Removed the MAF sensor and housing. There was a fair bit of grot on the mesh filter and the platinum wires were covered with carbon as was the other (more obvious wire) Used IPA spray (from Maplins if I remember rightly) and cotton buds to gently clean the housing and the wires also cleaned the electrical plug contacts as well. Let everything air dry and then reassembled. Replaced the wiring connector. Result ....perfect running and maybe even better than running with the MAF sensor wire disconnected. Had a check of the inlet manifold no cracks visually apparent so sprayed a bit of WD40 on and around the manifold whilst the engine was running and no difference. So it looks as though cleaning the MAF has cured my problem. It is like driving another car. Time to remove, clean and reassemble about 45mins.
 
#18 ·
@ madnoel10 re: MAF

Yep, that would corrospond to what I've observed now - in particular fuel economy has improved from 10.0l/100 with sensor disconnected, to 9.0l/100 with new sensor in place. This is over nearly identical usage and routes.

It would appear the ECU now has better control over the fuel mixture, now it has more accurate air data.
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top