18 vvc

[humtty]

hi long time now but i got a mgf 18vvc and it wont rev past 5500 i found what looks like an ond timing belt in the boot ,i been looking on the net and thay say it could be out of itme but ive looked for some timing marks but with no luck .some one git to know were thay are. thanks

[Mike H]

Could be due to any number of issues, but is there any service history with the car?

If not, my inclination would be to get the belts, tensioner and water pump done, coupled with a full service. That should eliminate any obvious issues, and having ensured the belts etc have been replaced, take it from there.

If the problem still exists, then does it rev freely to 5500 rpm, is there any hesitancy or 'missing', or does it gradually 'run out of steam?

[humtty]

thanks mike when i got it the outher day there is a small belt in the boot looks like a timing belt .the car will go well but at 5500 rpm it starts to splutter but in top it is going at 120 mph so the speedow sez its no problem to us but will it brake the engine

[Mike H]

Is the belt in the boot a toothed belt? Sorry to be cynical, but the fact that there's a belt in the boot doesn't necessarily mean it's been recently replaced.

If there's any doubt about the age/mileage of the belts, then get them replaced (two on the VVC). If a belt or the tensioner breaks at the revs you're talking about then you will certainly be facing a bill significantly larger than the cost of getting the belts changed

Once done, you can then start looking for any other issues as I suggested above.

[humtty]

the belt is tooted a small one it looks new but has been cut to get off by the look of it i asked the old oner and thay say it has been changed .it runs ok till 5500 then it starts to splutter no knocks or rattles just wont rev past that

[humtty]

were are the timing marks for the vvc cam could thay be out

[jonty1951]

I think I'm right in saying the VVC mechanism is rather complex and very expensive to repair ie, the cams aren't working correctly at higher revs.
Might this be why the previous owner got rid of it ?

John

[Mike H]

Jonty, above, is correct that the VVC mechanism is a complex bit of kit, but I can't think of any reason why it wouldn't work correctly at higher revs only. It is possible that it is not operating correctly over the entire range, but only shows up a higher revs?

If you've got 10 minutes to spare, then there is a fascinating video here on how the VVC mechanism works.

I came across this amazing video courtesy of some Lotus friends. Apparently taken from a Rover dealership VHS video it's been posted by the Maestro and Montego Owners Club.

My last two cars were both VVC's and it was only after watching this I fully understood how they worked!

Edit: url corrected

[humtty]

mmm will have to get me hands in and look think i will check the sencers first i think it runs ok al low revs so it mite not bee the cams lets hope

[Mike H]

My inclination would be to check all the obvious first such as the plugs, leads, and air filter etc (clogged?). If it's only at high revs, without seeing it it sounds almost like electrics, breathing or fuel to me.

[chrisd998]

Limiting the revs is a typical VVC problem.
I had the same symptoms with an MGTF VVC160 following an HGF
It turned out to be a some sort of blockage within the VVC unit.
Diagnosed by my local main dealer and only took one hour to dismantle, clean and fix.
Hope this helps

[humtty]

thanks i hope its a bad conector or some thing like that .it beets overheating like the outher one leest with this one i got 200 milel be fore i thort some thing was wrong not 200 yards lol.