Odd Rattle

Lo all

I've done a search through the tech forum and not found anything the same as this...

On low revs, accelerating very slowly either:

Out of gear trying it out (ie on drive)

2nd gear pulling away from a junction I've slowed down for

I get a rattle that seems to be coming from the middle of the front half of the car (ish). A mattlic rattle is the best description. This kicks in at about 1.8k revs and stays till 1.95k revs. It is noticable if I blip the throttle past 1.8k revs and let it drop back down, on the revs dropping down the rattle is noticed very briefly.

Never notice it if I pull away in 1st gear as I'm probably giving it more than that many revs!

Some days this rattle isn't evident, some it is. Went on a 400 mile round trip the other day (23.4 mpg at an average of 90!!) and at the start it rattled, at the end it didn't. Rattled this morning.

lol.

No change in performance, everything is smooth, engine idles very quietly, no tappit noise, etc, etc.

Car is a N/A manual, 5sp.

Any ideas?

Could possibly be an exhaust, or heat shield rattle, have you had a new zorst fitted recently or is it an old system, could be a loose shield on a cat. Does it do it if you 'blip' the throttle sat still? Could you jack the car up (with axle stands of course!!) and possibly got under the car to get closer to pin pointing the rattle?

Graham..

Still the standard exhaust, no de-cats, no engine mods, 100k miles.

Yup it does it if sat still and I blip the throttle.

No axle stands, so dont fancy sticking my head under it!

You could try talking nice to your local exhaust place and see if they'll have a look for you. Dont let them fit anything though, even if they say your shocks and tyres are gone!! Sounds common though we get loads of cars coming in with heat shields rattling, if possible i try to weld them back on or takle them off. There is always the possible chance that a 'box' or cat has broken up internally. good time to de cat and big zorst!!

Graham.

Well I do fancy a CW de-cat and exhaust job :flame Dev so this may be just the excuse...

Loose baffles in the silencer maybe?

Get the car up on a ramp and give the silencer a good thump to see if it's rattling.

Where is the silencer located? Sounds like the rattle is about 2 foot max and slighty to the left of me as a driver?

I concur. Had some exhaust work done recently and at low rpm's I get a rattle from my centre section. Its a heat shield or summat. Until it gets really annoying I will let it rattle. Just a case of getting your local freindly MOT station guy to have a looksee and fix it or an exhaust place.

Think you may find it to be the second cat under the car near the front seats, it has a heat shield and a metal protection cover, these can come loose.

worth checking

Originally posted by mrboost

Think you may find it to be the second cat under the car near the front seats, it has a heat shield and a metal protection cover, these can come loose.

 

worth checking

Agree with mr Boost, just stuck my cat on for the MOT, and it gained a rattle, gonna get it back off today and replace CW de-cat pipe. Will remove the metal jacket from the CAT when it comes off - no point in keeping it.

Ben..