Engine Noise - Suggestions

[matt4478]

Ive noticed that my engine is getting increasingly more noisy - everything sounds fine below about 3000rpm, but above that its starting to sound really coarse and raw. Theres no discernable extra knocking noises or anything, but it just sounds really sh*t, and also really belt-noisy (I always complain about this, but apparently its normal). All the noise seems to come from around the head area towards the back of the engine... Im running Mobil1 0w40 and the current oil has done about 10000miles including one track day, so do you think it could be just that the oil needs changing? The engine definitely got more noisy when I changed away from Elf Ultimate 5w40.

The engine has never been what you would call quiet or particularly refined when giving it beans, but this noise basically sounds like the normal angry noise you get on full throttle, just quite a bit louder than normal...

If not, Im wondering if the exhaust manifold might be blowing - any easy ways to test it? Id usually stick my hand near it and feel for gas escaping but theres so little room down there its all really hot!!!

Whatever it is, it doesnt seem to affect the performance - its still doing the usual one day fast, one day slow routine...

Cheers guys and gals!

 

[BenR]

if it is blowing, then there will be lots of black soot comming from the leak.....

 

[matt4478]

Cheers Ben, Ill remove the silly plastic cover and have a look...

 

[DTWD]

All the old RTs do this. Perfectly fine upto 3k, then all of a suden there is engine noise. But the difference is, its quite a nice noise, unless your driving on the MWay for about 3 hours, then it gets annoying.



Paul

 

[DanG]

Id say change your oil... its best if you change it immediately after every track day... seeing as this is when you drive the car consistently hard you dont want any metal filings you may dislodge roaming round your engine for the next thousand miles.

Using 0w50 sounds a bit thin to me, you want the viscosity such that it will cling to parts of the engine and lubricate them. 0w50 will be like piss being flung round not coating parts as you want.

Give it a try, like you say the noise got worse when you changed viscosities.

 

[BenR]

0w50 wont be thin as the 50 weight indicates. itll be as thick as a single 50 weight (which is thick) at 100 deg C.........

plastic cover on the exhaust!!??

 

[Jonathan]

What year is the car, do you know about the tech note on early MK1 172s to do with cambelt noise ?

 

[Infinicar]

10,000 miles without an oil change - little wonder its noisy specially on thin Mobil 1 Oil.

Change it for 15W50 and keep it changed every 5k at least.

Paul

 

[matt4478]

Argh! This thread has gone mad!

I have 0w40 oil if that makes any difference.

I meant the plastic cover on the engine - the one that stops you seeing anything useful like brake fluid levels and the like...

I did the track day a few thousand miles ago and its ready for a 36000 mile service soon anyway...

Cheers everyone!

 

[matt4478]

Jonathan - yeah, mine was covered under that technical note (early Mk1 inTitanium) and its had a new cambelt about 20000 miles ago - that quietened it down a bit, but it seems to be coming back!

pmitchell - I did wonder about changing the oil sooner, but its a modern engine and its supposed to be changed every 12000 and run on semi-synth or better, so I hoped that using a good quality fully-synth for 12000 would be okay with just one track day in between? Hope so, as Ive got the ClioSport Derbyshire Rolling Road day to come in early April, and it wont have been changed before then - do you think I should change it before that to be on the safe side? Hows the Lotus Carlton BTW? (drool...)

Matt

 

[BenR]

your car should make good power then! lol

run in then abused!!!! oil, what oil! lol

 

[matt4478]

Ben - youve got me worried dood - Im certainly not trying to abuse it - should I change the oil ASAP or not? Theres only 2000 miles til my 36000 mile service, but the RR day will be before then... What to do?!?!

 

[BenR]

Dont worry too much.

I abuse mine, and my oil changes arent too regular, its at the service centre every day as i work there so it does get some attentiaon when i need it, but oil changes arent that freqent.

When was the last time you changed the oil?

Just read, 12,000 miles in just about the limit for keeping the oil in a usable state, i change before that at about 6000-7000 miles. But with new fully synths basically eliminating wear i woudnt worry, no major wear will be there as the engines only done 36,000 miles, barely used. All teh thrashing will have loosened it up and when you change the oil, itll be fine and dandy.

up to you if you want to change the oil before the service, its only a 1/2 job.......if your planning to do it yourself. Where abouts are you?

 

[matt4478]

Im in sunny Chesterfield, Derbyshire - Im tempted to give it a go this weekend at changing the oil myself (depends what the weathers like ) - might pop in to Renault and get a new filter - if theyre not too busy Ill get them to do it for me though

Matt

 

[BenR]

lol......Renault busy! when???!

 

[BRUN]

dont be chuckin 15W-50 in a bloody 172.......

what your usin is fine mate......if your that sure it was the oil then go to your local Elf / Total Station and pick up some Total Quartz 9000 5W-40, its highly likely its the same product as the Elf version...

ive got that in my RT an its sweet as a nut

 

[BRUN]

let us know how you get on mate

 

[matt4478]

Shower of bast*rds!!! (Renault that-is)

Well, after asking Renault what was wrong with my car (again) and getting blank faces and "they all sound like that" responses, I took my car round to my uncles garage - within minutes they had found the cause of this f*cking harshness as I rev the engine - the top of my bast*rd plenum chamber wasnt bolted down properly! (Sorry, still pissed off with Renault gimps ). Ive had this noise for as long as I can remember, but recently its been getting much worse, my Uncle reckons that the bolts werent tightened and have been making a bid for freedom recently - the result is that the whole inlet manifold was vibrating loudly on the top of the engine when I revved it - hence the noise!!!

He suggested that maybe this has been wrong since my cambelt was changed around 20000 miles ago - and I think he might be right. Why cant Renault monkeys be trusted to get anything right? And what else have they forgotten to tighten?

Anyhow, my car now goes like a silver missile again and sounds sooooo sweet - Im just sooo happy with it now again.

Thanks for all your help guys!