Knocking Noise

Post by **Kit Bones** » 04 Dec 2005, 17:41

Hi all

Liking the look of the new site. I haven't posted for a while but I've been keeping an on eye it every now and then.

Could anyone please give me any ideas on my latest noise?... a knocking sound coming from the rear on acceleration especially on an incline (i.e, under load). Been getting steadily worse but only seems to occur after about 30 miles of driving on motorway. If I take my foot off the accelerator the noise stops immeadiatley but kicks back in when I put my foot back on the gas. Also seem to have a definate decline in power. On standstill the engine idles OK and up to 2000rpm or so without any knocking. I've got new CV joints on both sides at the back so I've ruled that out and a recon engine with about 2500miles on it.

It's an '88 2.1i DJ with the prop dropped out.

Any ideas would be greatly appreciated as always!

Cheers, Chris

Post by **matt** » 04 Dec 2005, 18:37

never rule anything out
i'd be checking the tightness of the bolts on the cvs....

Post by **terryvanman** » 04 Dec 2005, 21:18

I had this
turned out it was just the centre nut needed tightening on one of the back wheels.
took it to jacks and he just removed the brake drum, ran a grinder around the rim, fitted it back
and re-tightened the nut using a length of scaffold pipe.
all while i waited and at no charge,,,,,,a miracle for jack,,,,,i think i gave him £10 out of shock. .....hope thats all it is darling
terry

Post by **HarryMann** » 04 Dec 2005, 22:29

ran a grinder around the rim

Presumably it had new brake shoes fitted not long before Terry?

As Matt says, there are 12 bolts on the inner CVJs that would be the first to check, then move on...

Post by **matt** » 04 Dec 2005, 22:33

HarryMann wrote:
ran a grinder around the rim

Presumably it had new brake shoes fitted not long before Terry?

As Matt says, there are 12 bolts on the inner CVJs that would be the first to check, then move on...

fcuk my hat

matt runs round room shouting

"matt's a mechanic matt's a mechanic matt's a mechanic"

Post by **HarryMann** » 04 Dec 2005, 22:45

"matt's a mechanic matt's a mechanic matt's a mechanic"

Well, let's keep things in proportion shall we, Matt

Do you want those old brake discs - if so, when and how?

Post by **matt** » 04 Dec 2005, 23:11

not mot'd it yet Clive
just built a wasps nest out of exhaust putty round flanges.......

Post by **HarryMann** » 04 Dec 2005, 23:32

A constant battle eh?

Some old open weave glass cloth mixed up in that wasp's nest might be an idea, as they have a habit of cracking up and falling out... but its' just for Mot then, best of luck.

Post by **matt** » 04 Dec 2005, 23:38

2 x zorst bandage
2x zorst putty tubs
1x muddy bum
jobs a good un
going to paint it in high temp paint

total cost
£4 hhahhahahaha

Post by **Kit Bones** » 05 Dec 2005, 09:40

I'll check all my CV bolts etc tonight. The AA guy reckoned I could have a dodgy coolant pump. Better get booked into Jacks I think, I'll mention your centre nut problem Terry, cheers.

Chris

Post by **Kit Bones** » 05 Dec 2005, 09:49

Not sure if this will help but the noise is a rapid knocking almost like a hammer drill. Just thought I'd mention it. Louder than tappets. When it kicked in yesterday on the motorway I heard it over the volume of the stereo. I might try driving it with the engine lid off and get a mate to try an pin-point the source.

Post by **HarryMann** » 05 Dec 2005, 12:06

Really, the 1st thing to determine is:-

Engine speed dependent
OR
Road speed dependent

..simply by changing gear and returning to the same rpm and load, whatever the speed that gives, although of course, there could still be some confusion

Your last post seemed to be implying the former, whilst everything else above implies the latter (to me) - If the engine was making that sort of noise I imagine you would be in serious trouble and possibly with an oil light or buzzer on

Post by **Kit Bones** » 05 Dec 2005, 13:18

Initially I thought it was road speed dependent (60-65mph) until yesterday when I had to drop right down to 20mph, the noise was still there. But it only appears when I put my foot on the gas and stops as soon as I take my foot off. Engine sounds fine on standstill. Temperature is normal. No oil buzzer light. It's difficult to tell where its coming from as I have to be moving and it got so bad yesterday I got a tow home so I'm wary of driving it any further.

Post by **HarryMann** » 05 Dec 2005, 15:49

So check those bolts, both inner and outer cvjs (jnside the trailing arms) (5mins), and just a quick look around the engine bay to see that nothing is rubbing against pulley etc.

Under load the engine and transaxle push up at the front, so check the forward prop drive flange

Failing that, jack the whole back up and in neutral spin the wheel and look, listen and feel for something wrong. Ensure difflock is off too.

Post by **syncroand101** » 05 Dec 2005, 16:09

Chris,

Have you got much light round your way?

I can pop round one evening and help you have a play make sure all the obvious is tight etc...