Noisy K Series Engine

[principalgreg]

Had a great day at the Nurburgring on Monday and still can't get the smile off my face

Everything went well except, the speedo pickup fell out of the gear box and was banging agaist the bottom of the car as we went through the Karrousel. Took it off and lashed cable to cross member and off we went again. This time the engine was very raucus under load and seemed down on power. Returned to car park and check car over. Engine ran and reved smoothly, oil level and pressure fine. Went out again and noise level unchanged. Pressed on and car ran OK, but still down on power.

 

Speedo looks easy to sort, but curious about engine. Had a head rebuild two years ago, so should not be tired. Could it be the silencer packing> Any suggestions/insights welcome. Its booked in to Caterham in a week's time and I would like to narrow down the possible causes so as to brief them.

[shn7]

Wet (with/without Apollo?) or dry sump? What tyres? What sort of noisy?

 

Hoping it's not a result of oil surge leaving bearings lacking oil.

 

Steve.

Not forgetting Percy the Polar Bear who recommends

Puddle Pet Care

[principalgreg]

Wet sump with Appollo tank, yoko A021s. I guess that its the exhaust note that has changed. I'm used to the noise the engine makes when it is working hard and it has changed to become more raucus. If I had to guess, I would say it isn't the bearings. Oil pressure is unchanged. Could it be the exhaust valves leaking?

[Stationary M25 Traveller]

Is it a repackable exhaust ... if so, easy to take the can apart and look inside ... repack as necessary.

 

If a sealed CC original, it will be packed with stainless steel wire wool, which does not burn away.

 

 

[shn7]

OK sounds like it's not engine internals which is news.

 

Could it be an exhaust leak? This can add a cracking tone to the exhaust note and maybe resulted from vibration.

 

Steve.

Not forgetting Percy the Polar Bear who recommends

Puddle Pet Care

[CageyH]

Do you have a catalytic converter?

 

Only dead fish go with the flow....!

 

Edited by - CageyH on 27 Aug 2010 12:36:24

[Steve-B]

Our exhaust manifold took such a shaking on the ring that the next AM i was out with the socket tool tighting up the nuts. solved it for me, at the time had about 15K miles on car which was slowly / progressively some what louder.

 

easy fix to test

 

 

 

[principalgreg]

Thanks for the responses guys. Don't think it has a cat (ashamed to admit I don't have a clue!). Will be checking the exhaust maifold and silencer this weekend. The 'ring certainly does give a car a good old shaking (hence loss of speedo), so I can see that it might have had similar effects elsewhere.

 

[Mick Day]

My speedo drive fell out on my 1st visit to Germany as well!

 

Noise: check the engine mounts are secure as well as the plug cover. And really just check all fasteners around the engine bay. Similarly check the rear exhaust mount.

 

Power: could be you're getting quicker & a more powerful engine is required? Just a thought.

 

Enjoy a steak on a hot stone tonight at the Pistenklause?

[principalgreg]

Fitted new engine mounts last year, so they should be OK. Fortunately, I also refitted the front wings using special fasteners and cable ties or I am sure that they would have been shaken off too. Can't refit the speedo pickup as it did three lap dragging on the road and isn't quite as it left the factory now! I will check exhaust manifold bolts and silencer packing this weekend.

Could be that there is a thread on pre-Ring preparation. If not, could be useful.

[Mick Day]

Fitted new engine mounts last year, so they should be OK.

Check the mounting bolts are OK as some have been known to fracture as they enter the block.

[CageyH]

Have you checked that the spark plugs are still tight?

If one is loose, you'll be down on power, and it will make more noise...

 

Only dead fish go with the flow....!

[principalgreg]

Woe, woe and thrice woe! :boohoo

 

Yesterday, checked maifold, exhaust and plugs. All OK. decided to go for petrol and see what it sounded like. Still revved sweetly at standstill. After a few hundred yards, engine cut out and simply spun on starter with little evidence of internals moving. Investigation showed that cam belt was not moving, but still under tension. Belt was new three years ago (about 3000 miles), so I am speculating that the crank pulley has failed, though belt could have stripped, or both. I am wondering if head has lunched itself. That would be my second in four years (dropped a valve in 2003).

 

Time for a stiff drink and a peer group!

 

Ho hum. Well at least it didn't go at the Ring.