What could it be?

[shinji]

I've been racking my brain (or lack thereof) trying to think what is wrong with my vee based on the following symptoms:

1) takes at least 2 goes to start the car on a cold engine (like left it over nite). This seemed to appear after I replaced the cam belt in July.

2) strong unburnt fuel smell in the cabin and outside the car after the cold start and this maintains for at least around 5-6miles.

3) weird engine noise when you accelerate up starting from about 2.8k to around 3.5k rpm and it subsides when it goes past 4k. The sound is kinda like when you caught yourself in too high of a gear and in low engine speed. This sounds also occurs when the engine is at normal operating temperature.

4) fuel economy has been bad and I have only been driving around in dense traffic, as you do in urban region of Hong Kong. I'm getting around 13mpg to 15mpg [smilie=icon_eek.gif]

I'm thinking along the lines of the fuel pump, fuel pressure regulator or the filter. Am I on the right track?

Hope you guys can shed some more light on it. Thanks in advance.

 

[d7ve_b]

Sounds rich, what do the plugs look like?

Are you sure the timing is correct? Anything a tooth out?

 

[Brett]

Cam timing could be out.

 

[shinji]

Cam timing could be out.

Sounds rich, what do the plugs look like?

Are you sure the timing is correct? Anything a tooth out?

The belt was done at Renault HK and not the first time they did it cos they also did WONGY's. Is there a simple way to check if the timing is a tooth out?

 

[Brett]

Not really. Could also be cam dephasers. A few people on here have had issues with them and im sure mine were dodgy in my old engine.

 

[GTTurbo]

Possibly lambda sensor?

 

[Anonymous]

If it started straight after the cam belt change I'd be concerned the timing maybe out or something they removed wasn't replaced properly or was broken.

 

[shinji]

Not really. Could also be cam dephasers. A few people on here have had issues with them and im sure mine were dodgy in my old engine.

Are referring to the dephaser pulleys? I got these replaced during the cam belt change.

If it started straight after the cam belt change I'd be concerned the timing maybe out or something they removed wasn't replaced properly or was broken.

Seems like the consensus here would be a timing issue with the engine.

What else can it be?

 

[Andrew C]

+ 1 for Lambda Sensor based on all things listed especially poor fuel economy.

 

[WONGY]

Take it back to Renault tell them to investigate

First the computer for faults after that manual checking timing etc plus they can put a clip on the computer drive the car and check fuel pressure - that's what they did to my Clio v6 when the fuel pump was found to be broken

Oxygen sensor - read this topic - normally you get black smoke from the exhaust when mine broke

Better to buy them from uk much cheaper btw

viewtopic.php?f=13&t=10646&p=88472&hilit=Oxygen+sensor#p88472

 

[rustedandrotten]

Take it back to Renault tell them to investigate

First the computer for faults after that manual checking timing etc plus they can put a clip on the computer drive the car and check fuel pressure - that's what they did to my Clio v6 when the fuel pump was found to be broken

Oxygen sensor - read this topic - normally you get black smoke from the exhaust when mine broke

Better to buy them from uk much cheaper btw

viewtopic.php?f=13&t=10646&p=88472&hilit=Oxygen+sensor#p88472

Most sensible advice in the first line!! There is no point trying to second guess, get it on the diagnostic and let them sort out what they have done! You probably paid a packet for the work done and the car came back with an issue that wasn't there before, it is probably therefore safe to assume that they have failed to connect something, incorrectly timed it or just plain broken something. The car went in for routine maintenance so it should have come back in rude health, they are the main dealer, they should be fully trained and competent to undertake the work with all the relevant factory equipment and support!

Hopefully it is something simple like a connector or hose not fitted properly, good luck!

 

[shinji]

Thanks guys for the suggestions and comments! I now have a better idea and hopefully Renault HK won't give me the runaround and say there is nothing wrong with it.

I have contacted Renault HK and trying to book a date to take it in.

I haven't noticed any substantial black smoke from the exhaust as WONGY suggested when you have a (or a couple) dud oxygen sensor.

Will report once again once it has diagnosis.

 

[WONGY]

Cool btw davilamb took his car in and during test drive they wrote it off looks like huge smash!

Hope he posts pics soon

Seems their standards going down

 

[Brembov6]

[smilie=icon_eek.gif]

 

[shinji]

Cool btw davilamb took his car in and during test drive they wrote it off looks like huge smash!

Hope he posts pics soon

Seems their standards going down

Holy sh!t

Davilamb has a nice vee too

 

[shinji]

An update and a request for help.

The vee is now at Renault HK and they diagnosed as a leaking fuel rail (see pic)

I'm not sure how common it is for this part to fail and how readily available this part at Renault France. It carries the Part No. 96 30 333 080 and the Renault HK was also I will need new seals (for the injectors too) P/N: 77 01 476 833. Would someone be nice enough to check whether the part is available and roughly how much?

The other weird thing is when I looked up the fuel rail P/N from the KB, I found this which is different to the one in the car and the photo that the Dealer looked using my VIN.

From the Knowledge Base

From the Dealer

Can anyone shed some light on why there is a difference?

 

[WONGY]

That's interesting cos my cars has a bit of a fuel smell lately as well and I sometimes get an uneven idle like an air leak.

But no misfiring so I figured it's something degrading like a gasket or rubber pipe and would wait to see if it gets worse

Would think it's an available part eg common with Lagunas etc?

Have you tried Scott or Renaultparts direct here?

 

[Jamesv6]

item 1
INJECTION RAIL
96 30 333 080
£22.07 GBP


INJECTOR SEAL
77 01 476 833
£27.83 GBP each

 

[shinji]

item 1
INJECTION RAIL
96 30 333 080
£22.07 GBP


INJECTOR SEAL
77 01 476 833
£27.83 GBP each

Awesome James! Thank you Sir :salut:

The price that Renault HK is screwing me was (converted from HKD to GBP) were:

Injector rail
GBP124.81

Injector seals
GBP107.81

 

[shinji]

That's interesting cos my cars has a bit of a fuel smell lately as well and I sometimes get an uneven idle like an air leak.

But no misfiring so I figured it's something degrading like a gasket or rubber pipe and would wait to see if it gets worse

Would think it's an available part eg common with Lagunas etc?

Have you tried Scott or Renaultparts direct here?

I think the fuel rail part would definitely be common with Laguna V6s of the same vintage but i doubt the injectors will be though. The Peugeot 406 V6 may also share the same part since they the same engine.

WONGY, I didn't experience any misfiring or backfiring just strong fuel smell in the cabin and from the side vents. The fuel consumption also gone up too.