Hi

I have a 1360 crossflow in my Locost and it has developed a rattle.

I was driving along giving it some stick in third gear, I heard a noise like something came out of the exhaust or a stone hitting the exhaust. I didn’t take much notice as the car was ruining fine. As I slowed down the engine started spluttering and cut out. I pulled over and checked under the bonnet and everything was fine. I tried starting it, it didnt want to start and sound very different. I tried again after a few seconds and it fired up and ran fine apart from a slight rattle or a Tappetty sound on tickover. I drove back home and it seemed fine apart from the tappetty sound which was loud on the over run sounds like a Ford ka. When I got it home I check the valve clearance which was all ok apart from one exhaust valve on cylinder number 4 which was slightly out. I also check the spark plug and found that number 4 didn’t have a gap, so I gaped it and took it for a test drive and everything was normal, Until a little while after giving it some stick in second gear the same thing happen again got it home and check the clearance and plugs everything was fine. But it still sound tappetty. Especially on over run.

I don't think it has a rev limiter and think I may of over revved it.

What could it be? Any help or advise would be much appreciated.

Thanks

[Edited on 17/7/09 by Sij]

Big end bearing has gone. They always make more noise on the over-run and if bad enough can cause the piston to clout the spark plug and close the gap up.

Do you have an oil pressure gauge? If so what is it saying?

Shell bearings yes it could be. Is there anyway of checking them apart from droping the sump and checking them

I do have a oil pressure gauge I didnt notice what it was reading, I will check it when I get a chance.

Hi

Possibly a burnt out exhaust valve on #4. Check compression on all cylinders if it's valve related on #4 it will be down a long way compared to the other three.

Cheers Matt

The car does run fine. The performance has'nt been affected. There is no misfire either. However it dosent sound normal I think the exhaust note is slighly louder than normal.

Also there is'nt any smoke emitting from the exhaust.

I will check the compression.

Cheers

Hi

I have replaced the big end shell bearing which were worn. But the rattle is still there on the overrun

Oil pressure is showing 60

Any ideas what it could be?