Renault F9Q 1.9 dti economy ( Laguna / Megane / Volvo S&V 40 )

Hi,

Further to my earlier posts, I've ironed out some of the factory fitted design flaws on my recently aquired 1999 Laguna RT dTI eg seized bonnet catches, snapped exhaust hangers, leaking door membranes etc etc

So now its back to the engine....

The only TDI I can closely compare my Laguna with is an Audi 80-TDI 90bhp which I ran for 3 yrs problem free. Despite its 256000 miles, the Audi always started instantly and returned a consistant 51 mpg just like the figures on the Parkers guide. It wasn't a quick car, but it never consumed oil or smoked etc..but maybe it was a little bit rattly especially when cold

In comparison, the Renault F9Q engine has done 134000, it seems quiet ( well ..not rattly ), it doesn't smoke. Its too early to tell if it sups oil, but it isn't a good starter and its only returning 46.5mpg....plus it doesn't feel particulary quick for 100BHP. It is supposed to be 2 secs quicker 0-60 than the Audi, but feels slower and flat especially when cold.

Starting: It has had a new battery the day I bought it in December, but even considering this ( and its since had a full service with air&fuel filter change plus 2 doses of injector cleaner in the tank) it is a cow to start especially when the ambient is less than say 5°C. It needs to be cranked for

10-15 seconds, then let the glowplugs have a second or even third go before it fires up. I didn't think the glowplugs were knacked, because when it does start it isn't lumpy/misfiring/smokey etc, just flat.

MPG : Using the Parkers website guide for reference, the A80-TDI averages

51mpg which is precisely what mine consistantly did. Sometimes I reached 680miles on a 60ltr tank, usually managed 630miles for about 55ltrs of diesel. The 1.9dTI is listed on Parkers as 50mpg ( although I'm sure I've seen 51.4mpg in other literature elsewhere). This moring I needed to refuel and I put 57 ltrs in the Laguna for 583 miles, which equates to only 46.5mpg. I'm a bit miffed if this is all it can do, because I could of had my pick of Pug 406'std TDs but opted for a direct injection diesel to maintain 50+ mpg

Power : I've had a play in a 2001 Mondeo TdCI and a 130PD Passat and they feel like rockets. I didn't expect this Laguna to be a dragster, but similarly I hoped it would accelerate quite nippy. To be honest it feels quite lathargic. As mentioned above it is very flat when cold and doesn't get much better. There is no instant turbo surge, more like a 2 second time delay from pressing the accelerator to getting some limited action. When it does accelerate, it doesn't feel smooth, it does vibrate more than the Audi ever did.

In consideration of the above, I'd like to receive Renault F9Q driver's views on what MPG they get, plus anybody elses thoughts on whether my car is nursing a problem, such as fuel delivery , air intake probs ( MAF failing or turbo pipes leaking ), or exhaust/cat probs.

Does anybody know any diesel tuning specialists in or around the Manchaester

Leeds areas that could offer a 'check & report' service.

Also, has anybody any knowledge of whether these engines can have their ECU's sucessfully remapped for eg 30bhp gains ? i.e I can suffer 46.5mpg if i can outdrag a 130PD Passat, but want 50+mpg if I have to get used to the power it currently offers.

Thx

Reply to
Ebodski
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These never were as brilliant as an XUD, but should be a willing if noisy and gruff performer. Sounds like yours is suffering as it should definately be going better than it is.

I would start with having the injectors refurbished, and whilst they are out, a compression test. Being a DI, it shouldnt be needing its glow plugs much even at 5oC. So something is definately wrong.

Reading your post again it seems to me that your engine is giving all the symtoms of being abit past it, but lets hope not.

After the injectors and having someone who is familiar check the cam and pump timing with a dial gauge- the only way to get these set up right) I would check the boost pressure, and the sense line to the MAP sensor, as this would cause flat performance, but not poor cold starting... A check of the ECU for fault codes would be in order to.

Tim.,.

Reply to
Tim (Remove NOSPAM. Registry corupted, reformated HD and l

I agree, my XUD in my Synergie does have a surge of acceleration, although its gearing is short.

I really find it hard to believe the F9Q is past it at 134K miles & 4½ years old. Its been serviced by Renault Leeds but there's a missing stamp for

120K, so its either been serviced as unrecorded or just done 24K before I did its oil change ( I use Millers XFE synth )

I've just checked with a work colleaugue today who had a 99-T dti Laggi from new to 80K. He does more miles than I. He got up to 55mpg out of his ( 650 -

700 miles per tank ). It started at 650 per tank and improved to nearly 700 as it got older. Mine did 583 miles when I last filled it from empty (57ltrs )

I'll go with your suggestion about refurbing injectors though.

Do you know any diesel experts in the north of England who can carry out such a task ( preferrably Manchester or Leeds ...or anywhere in between )

Thx

Reply to
Ebodski

It may not be the right answer, but if it is, it's cheap to fix.... I had a similar sounding starting problem with the F9Q engine in my 1998 Scenic.

I traced the problem to the sections of fabric-covered flexible black rubber piping that forms the "overflow" return for diesel from the injectors back to the fuel tank. The rubber had perished inside the fabric sheathing. When the car was at rest, air was very slowly being sucked in through the cracks in the rubber as the diesel settled by gravity. The air was finding its way back through the injector pump assembly, and was collecting in the fuel pipe on the fuel filter side of the pump assembly. Fortunately this section of pipe was clear, so it was easy to see the air. When starting, it took a while for the air to be purged through - 10 to 20 seconds of cranking at times..

It was very difficult to see that the rubber piping had perished due to the fabric sheath. I bought a 1 metre length of the piping from the local parts shop for about 3 quid, and cut the sections to length. No problems since.

As I said - it may not be the answer for you, but it may be worth checking....

Splodge

Reply to
splodge

I'll go with that suggestion......, perishing elastomers are a common theme with Renault. Eg leaky seals ( I've still got a leaky power steering hose to sort out , thats next on the fix list ).

To back up your theory, the only time I had starting trouble on my Audi 80 TDI was after I fitted new fuel filters. I could never properly bleed the fuel line and it was always a bitch to start after a service.

My Synergie and this Laguna have 'squeezey hand pumps' ( technical term...) so they expel air no bother.

My 256000 Audi had a battery which was a few years old, and it cranked the engine quite easily. I could crank it for several minutes. This 134000 Laguna has just had a brand new correctly sized battery and despite this, it feels like if I crank it for more than 10 seconds it might drain it flat. Don't get me wrong, I think this is a good sign, i.e. the engine has full compression.

I'll have a play at weekend and see if I can spot anything. One immediate test I could try is to squeeze the hand pump a few times when the engine is cold. If the engine fires up instantanously, then the answer lies there.

Whilst the above could sort out my cold starting woes, I don't believe thats why I'm only getting 46.5mpg. I would still like to know if there's any diesel tuners in Northern England who can refurb injectors ( ultrasonic cleaning ? ) and do diagnostic checking. Anyone know any place ???

Reply to
Ebodski

snip

Mine is not that fast either and fuel consumption varies. 550 - 700 a tank, with what I would say is similar driving. Both route and technique!

I have a good easy starter

In conclusion it has 180245 miles on the clock and still runs the same as the day I got it.

Pete

Reply to
Pete

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