MatraSport Forum

Each model => Espace => Topic started by: tka on November 20, 2006, 06:12:10 pm



Title: How does VVT work
Post by: tka on November 20, 2006, 06:12:10 pm
Hi all

Does anyone know in detail how the VVT on the 2.0 16V engine works. How is the variable timing controlled etc., is it a pure mechanical construction or? I've browsed the Internet and various manuals (on Espace's, Laguna's etc) for some exploded views or like, but with no succes.

My car '2000, Espace 2.0 16V has developed a 'diesel-engine-like' rattle, wich comes and goes periodically at idling. Sounds like the noise evolves from the camshaft area (but difficult to determine of cause). When engine speeds up the rattle disappears.

The engine seems to pull fine at low and middle range, however I suspect top-end power might not be at original 140 HP-level (not much acceleration felt from 130-140 km/h an onwards, but haven't had that measured exacly).

Every suggestions welcome...

Best Regards
/tka

Thomas Kjaer-Andersen, Denmark



Title: Re: How does VVT work
Post by: Anders Dinsen on November 20, 2006, 11:30:39 pm
Hej Thomas

Jeg tror ikke at din 2.0 16V motor har VVT, men hvis den har er det nok mekanisk/hydraulisk styret. Derimod er jeg ret sikker på at den har hydrauliske ventilløftere og at det er derfra at din lyd kommer. De virker ved at olie trænger ind i dem hvorved ventilspillerummet elimineres. Ideen i dem er at man ikke skal justere ventilspillerum men at det justerer sig selv uafhængigt af motorens temperatur. Det giver mindre forurening når motoren er kold.

Desværre også typisk problemer når de stopper til eller bliver slidt.

Jeg foreslår at du kontakter et værksted som kender den motor, altså et autoriseret Renaultværksted.

English summary: I don't think Thomas' engine has variable valve timing, and I think the problem is the hydraulic lifters on the valves. They can make this kind of sound.


Title: Re: How does VVT work
Post by: tka on November 21, 2006, 01:24:50 pm
Hi Anders

Thank you, but how sure are you about the non-VVT design?

I thought the F4R used in the Espace was VVT, - the techinal stuff somehow incorporated with the wheel driving inlet camshaft. My reason for not at first suspecting hydraulic valve lifters, is the perodicallity of the rattle. When idling the rattle comes and goes. It's not always present, but can suddenly be there for let's say 30 secs, then disappear for let's say 10 secs, then come on again etc. Sounds mostly like 'some mechanism contolling somthing' beeing out of order. 

Well, I might have to end up going down the Renault garage/expert route as suggested. Apparenetly there is not very much F4R-information 'floating' around the Internet.

Best Regards
/tka


Title: Re: How does VVT work
Post by: Lennart Sorth on November 21, 2006, 08:04:56 pm
how sure are you about the non-VVT design?
I don't think there has even been an Espace with a VVT engine - does Renault make them at all ?

let's say 30 secs, then disappear for let's say 10 secs, then come on again etc.
Sounds mostly like 'some mechanism contolling somthing' beeing out of order. 
Thats a French car, isn't it ? :-)    (sorry, couldn't resist it)

The noise could be worn valveguides/lifters or worn timingbelt tighteners ? - is it reproduceable at certain revs ?

/Lennart



Title: Re: How does VVT work
Post by: tka on November 21, 2006, 10:29:14 pm
Hi Lennart and others

Well, that some F4R's are actually VVT designs, I'm quite convinced of. Eg. study the x-ray picture at http://www.renaultclub.cz/pictures/a9558e4e4723b11c258d5f662eda79a1.jpg. Notice especially the difference between the inlet and the outlet-camwheel. The inlet camwheel construction includes the the VVT mechanism, beeing able to offset the inlet camshaft at an angle depending on conditions. Looking very carefully in the Bucheli Verlag Espace manual, it could be interpreted that the Espace F4R-700 has the same construction. - However, how this exactly works, and by which means it's controlled I don't know.

I've now browsed the Espace Freunde (german language) Espace forum and discovered a very interesting thread named "16V - Leistung: mangelhaft! (16/10/06)". Despite my German being rather ...let's say lacking... I've found that symptoms mentioned in this thread are very like thoose in fact experienced from my vehicle.

After the problems described was eventually solved, Frank writes the following:

"...Der sagte gleich, dass man da was finden MUSS und er hats auch gefunden: das Ventil, das die Hydraulische Nockenwellensteuerung steuert, war total verstopft. Er hat vor der Reparatur einen Test auf dem Leistungsprüfstand gemacht. Erstaunlicherweise war die Endleistung 103KW, aber mit heftigen Leistungslöchern dazwischen.

Nach der Reinigung des Ventils sind die Leistungslöcher weg und das Auto hat (laut Diagramm) 110KW.

Das Beste kommt aber noch: Auch das nervige Tickern, von allen als Hydrostösseltickern diagnostiziert, ist komplett weg!! Außerdem läuft der Motor viel gleichmäßiger (im Leerlauf kein Wackeln des Ganghebels mehr). Erstaunlich, denn auch mein Landarzt kann sich das Tickern im Zusammenhang mit dem verstopften Ventil nicht recht erklären.
 
Daß eine ausgefallene Nockernwellenverstellung sich so stark bemerkbar macht, ist der Renault Werkstatt offenbar gar nicht bewußt. Ich hatte nämlich damals sogar dort gefragt, ob mein Problem nicht damit was zu tun haben könnte, aber der Chef meinte, dass sich das anders (weniger)äußert..."

In english (as understood by me!) the above says, that Franks lacking-power-problem etc. was due to a (hydraulic) valve controlling the 'camshaft-adjustment' beeing blocked. Seemingly cleaning the faulty component immediately solved both the power problem and various side effects as ticking noises, rough running etc.

As Frank puts it in the end: Extremely relevant knowledge for 16V owners.

Has anyone here knowledge of the exact valve referred?

Best Regards
/tka


Title: Re: How does VVT work
Post by: Anders Dinsen on November 22, 2006, 01:48:31 pm
As Frank puts it in the end: Extremely relevant knowledge for 16V owners.

Has anyone here knowledge of the exact valve referred?

YOU ARE RIGHT! I was wrong. Very useful information!
No I don't know the valve...

If you remove the timing belt cover you should be able to identify whether the timing pulley has the VVT-mechanism as you correctly point out that it looks different to a basic pulley.

Hvor i Danmark er du?

- Anders :)


Title: Re: How does VVT work
Post by: roy4matra on November 22, 2006, 04:49:50 pm
Hi all

Does anyone know in detail how the VVT on the 2.0 16V engine works.


Yes, I do.  I have replied to Thomas by email since I was not initially registered here.  The document that coveres this is a 22 page technical note and requires special tools to change a dephaser, if that has failed, but it could be a number of other things which all need to be checked first.

If anyone else needs to know the specifics, please contact me by email.

Roy


Title: Re: How does VVT work
Post by: tka on November 22, 2006, 09:13:53 pm
Thanks to all for involvement... - And special thanks to you, Roy, for the very useful information sent to me directly.

For everyone else's information, it can be concluded in short here that: Yes, the 2.0 16V is a VVT engine having a mechanism built together with the inlet cam pulley. The mechanism is able to offset the camshaft rotationally an angle to the pulley, thereby dynamically adjusting inlet valve timing. Offset is activated hydraulically, controlled electro-mechanically and in the end decided by the engine management computer.

Whether the rattle, possible power lack etc. on my engine is actually related to failure of some component involved in this setup remains still to be investigated.

Useful knowledge to start on, however. - And since my car is still un-taxed here in Denmark, and not really running, there is no hurry yet. I will start/continue the thinking:-)

BTW what is a good solution for reading computer fault codes etc. Has anyone succesfully used the (fairly inexpensive) ElmScan 5 from www.scantool.net (only diesel's are on their Espace positive-list). I guess the system is basically OBD-II compliant but there are different protocols, is it CAN?. What about custom codes, setting up things etc.?

Best Regards
/tka

Thomas Kjaer-Andersen, Denmark (Hundested)
Espace 2.0 16V, jan. 2000, 99.000 km


Title: Re: How does VVT work
Post by: Anders Dinsen on November 22, 2006, 10:05:42 pm
BTW what is a good solution for reading computer fault codes etc. Has anyone succesfully used the (fairly inexpensive) ElmScan 5 from www.scantool.net (only diesel's are on their Espace positive-list). I guess the system is basically OBD-II compliant but there are different protocols, is it CAN?. What about custom codes, setting up things etc.?

Protocol is AFAIK not CAN, and there are generally problems using 3rd party tools to diagnose the Renault ECU's. Yes, they claim OBD compliance, but it's buggy. Apparantly they have little inclination to fix these bugs.

Thomas, da du er i Hundested vil jeg anbefale Autohjørnet i Espergærde. Det er nok det absolut bedste sted at tage hen med din motor da de er dygtige, erfarne, til at snakke med og autoriserede - dvs de har adgang til alt specialværktøj og dokumentation. Hils fra mig, hvis du ringer. Det virker som om du ved en del selv, så måske ved du allerede, hvilket værksted du vil bruge, men dem her kender jeg og mener jeg at kunne stå inde for.

Adressen og telefonnummeret står her:
http://dinsen.net/espace/reservedele (http://dinsen.net/espace/reservedele)


Title: Re: How does VVT work
Post by: tka on November 23, 2006, 09:45:28 pm
Hej Anders

Tak for tips. Vældig fin og infomationsspækket hjemmeside du har.

Må nok tage mig lidt sammen, før jeg ligefrem kontrakter et værksted for hjælp. Det har ikke rigtigt været praksis i min hidtidige bilene karriere! -- Omvendt må man vel erkende, når andre ligger inde med information og værktøjer, som man ikke selv har adgang til... Adressen noteret:-)

Sorry to all the others of you, for speaking danish here. We were just exchanging information on specific local Dealers/Garages...

/tka