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MG MGF Technical - VVC engine starts like a diesel when cold
|My VVC engine has a 'clack-clack-clack' sound when cold. (1996 P-reg 46,000 miles) |
I was in Ireland on Sunday driving in appalling conditions - lots of puddles and standing water.
When at the ferry terminal the Stena passenger lounge was freezing so I sat in the car with the engine idling for 1 hour. I noticed that the water temp was around 55% (usualy around 40%) I assume this rise was due to lack of airflow over radiator. Oil temp was around 90oC.
Could either of these conditions have caused the problem?
I checked the oil this morning it was around the min mark (no milkiness and no coolent loss from reservoir)
After filling and a 20mile run the noise is still apparent once the engine is cold again.
Paranoia is starting to set in.
Could it be engine bearings? VVC? Piston Slap?
It uses aprox 1 litre of oil (Mobil 1) every <1000miles (Rover dealership say that is within spec)?
It had new timing belts and water-pump 7000 miles ago and the only mod is a cat-bypass.
|Could just be your engine running low on oil. Better check for oil-leaks from underneath the car esp at cam-belt coverings i.e camshaft oil-seals.|
Hope its not HGF.
|could be the leads/dist as well. Getting on a bit, mine is sometimes a bit chuggy too.|
|I would be tempted to get your oil pressure tested|
The main bearings would make a loud knock under load regardless of temperature
Small end bearings make a lighter knock but again regardless of temp so it doesnt sound like those!
I am not sure if the engine runs on hydraulic tappets - if so these get worn and will rattle when oil is cold
this is due to ALL the oil running to the sump when parked and that it takes a while for oil pressure to build up enough to "take the slack" out of the tappets hence it clears as the oil gets warmer and pressure builds to the head
Its definately worth a check up at the garage - prevention is better than A REBUILD and a good mechanic will identify the noise !
|My VVC has made this clakety diesel noise at idle only since 10K Miles I am now at 47K and it is exactly the same. It is more noticeable when parked up close to something like a wall, as this echoes the sound. Original investigations showed that this is the VVC mechanism as MPi's do not suffer the same although power is unaffected. One thing I did do was put some of that Slick 50 silicone stuff into the engine at oil change, which did quieten it down quite a bit.|
Temperature rises are normal when the car isnt moving so I wouldnt worry. Some poor folks here have had problems with HGF however remember there are 1000s of MGFs around that have never had a HGF Just hope that yours is one of the 1000s. :)
|One thing I don't like about the VVC is that bag of bolts sound.. :-)|
|Sorry, Bucket of bolts sound...|
I agree with Richard and Tony.
My VVC (97P with 18,000 miles) sounds like a bucket of bolts shaken around when initially started. When oil pressure builds up (5 - 10 seconds) it quietens down a bit. When its all up to temperature, it quietens down a bit more, but never goes away.
Oil pressure has been confirmed as okay. No noticeable oil loss. VVC syndrome - some appear to be noisier than others.
I'm going to try Richards suggestion of the Slick 50 though.
|Noise from VVC top ends is well known and really somehting to live with. The engine sues hydraulic tappets and when the oil level drops well below the minimum they are the first thinsg to shout about it in a very marked increase in clatter, and I mean a marked increase. (Makes a cold starting diesel sound like a 6 cyl BMW enine!!!) This is a gypsies warning to sort the problem immediately and only if ignored are you likley to see a reduced oil supply to the vital bearings of the engine.|
1000 miles per pint is indeed acceptable and if it goesa to about 500 it will still be said to be within limits, but I suggest that this would be a little worrying depending on the type of use.
I note the use of Mobil 1. As a matter of interest at what mileage was this oil first introduced to the engine?
|I would check with MG re using slick 50|
Reason is that it can reduce oil pressure - had many cases of this on motorcycles due to the treatment affecting the operation of the oil pump wnere it actually causes oil starvation to the head !
Fully agree with Tony - stay clear of the Slick 50 and similare stuff! Why put anything said to be "filled with sub-micron PTFE" when it is all going to be trapped in the oilfilter ! Put the money on a good oil instead and if the car is fairly new - wait until fully run -in before changing to syntetic oil. It is all to tempting to do it at first oilchange...
Further on this : If I have been to eager with syntetic oil before the engine is fully run in, is it advisable to return to ordinary "Dino" oil to finish the run-in session ?
Regards , Carl.
|Would agree with comments on oil level. When I bought my VVC 2nd hand, I noticed the VVC unit was very noisy and had it replaced under warranty. The new one was better for a while but then started the same noise. I noticed that the oil was very low and that cured the noise to a big extent. I now keep on top of the oil level and it's less of a problem. It is always the first warning for low oil. Mine also burns oil. I guess I wasn't use to it coming from a Golf GTI that never used a drop. Do check the oil and top up to the max.|
|Tony and Carl,|
Thanks for tips ref Slick 50. I now choose the easy option to do nothing. Will turn up cd a bit more when cold.
|Pleased to hear that the "clacking" is not a serious issue. I've just bought a 99T VVC with 30K. I was a bit worried about the noise, but it seems to calm down atfer 5 mins or so.|
I also agree with the Slick 50 avoidance, and the Mobil 1 theory.
Anyone know of anyother common probs with the VVC?
|I've read/heard many bad things about Slick 50, about how it actually speeds up engine wear, oil starvation, filter blockage etc. Oil manufacturers spend a fortune developing synthetic oils with plenty of artificial additives already in them, if they thought putting PTFE in oil was going to help they would do already.|
My advice is keep checking your oil levels, change oil twice as regularly as recommended and use a fully synthetic 5W/40 oil - Mobil1 for example, or GTX Magnatec.
On your first change to a fully synthetic oil, some people recommend changing it completely again after say 500 miles as they think the change to fully synthetic washes out a lot of crud.
Just got back from a nightmare driving hol in Europe.
I think I know what the noise was....
First day on the continent something screwed up with the timing - the belt is intact but one of the top pulleys is loose.
The engine is stuffed and the AA are currently repatriating the car to the UK.
I had the belts replaced in April - 10,000miles ago.
The job was done by a local garage (not Rover) when a new water pump had to be fitted.
Is it normal procedure that the bolts are replaced along with the belts? If so then I could have a claim agains the garage since their itemised bill makes no mention of it.
The AA are sending the car to Mike Satur who will make a report on his findings.
I need help gathering evidence that the garage in Southport did a sub-standard job.
Does anyone have/know of any written procedure for the changing of the timing and VVC belts? Are there any workshop manuals out for this kind of stuff?
Your help would be very much appreciated.
By the way, get that noise listened to by someone who knows what they're doing!
|There are manuals available - but i would rely on Mike Saturns report - hear very good things about them - I am sure they will find the cause !|
Whether you can make a succesful claim against the origional garage is another question - they have us all by the danglies really!
I can hear all the excuses already - ie
"the cars been thrashed mate"
"its a rover fault not ours"
Hope your succesfull and get your money back but doubt you will get far!
|Incorrect torquing of the cam bolt which allowed it to loosen and lead to muching the engine. Dip into the archives and find the story on this for a number of engines.|
|I know this is too late now - but when trying to source a mechanical noise - use the old screwdriver to the ear trick - and make sure you dont have clothing that hangs down!!! - nothing worse than a tie caught in the fanbelt!!|
This thread was discussed between 09/10/2001 and 21/10/2001
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