charlieboo Posted March 9, 2007 Share Posted March 9, 2007 There is a loud rattling noise coming from under the intake side cam cover (wooden stick to ear trick). I checked timing belt pulley first, removed aux belt (to see if it was PAS/AC pump) but the noise is still there. It sounds like there is something metallic blowing around (my no 2 turbine shattered recently so was thinking it could be bits of that). I removed the intake and runners, but found nothing abnormal in there. I can see the valves and all look normal. Turning the engine over by hand I can see some of the valves moving up and down a bit, but I’m now not sure what I should be looking for. Any advice appreciated. Thanks. Link to comment Share on other sites More sharing options...
charlieboo Posted March 9, 2007 Author Share Posted March 9, 2007 I forgot to mention the following... 1. Rattle is in time with revs. 2. Gets louder with more revs. 3. Struggles to start (hesitates), but then does start and runs normally. 4. During idle, the revs drop at random intervals (anywhere between 5 to 20 seconds). Almost stalls, but picks up again. The cam position sensors aren't stuck, but I would imagine that if one was, then the noise would be similar. Link to comment Share on other sites More sharing options...
Wez Posted March 9, 2007 Share Posted March 9, 2007 Could it be the shims? Link to comment Share on other sites More sharing options...
charlieboo Posted March 9, 2007 Author Share Posted March 9, 2007 Not sure. When turning the crank by hand, the cam seems to make a smooth contact with them. It's a very loud rattle. It's quite scary to stand anywhere near the engine when its running. Sounds like there is a ball bearing being fired around. Could the shims cause such a noise? Link to comment Share on other sites More sharing options...
ChrisSZ Posted March 10, 2007 Share Posted March 10, 2007 If it's a regular noise then chances are it won't be lose bits of metal. No way could the turbo bits get up there either - I'd go with shims. Your best bet is to whip off the rocker cover and have a good nose around - get some feeler gauges too. Link to comment Share on other sites More sharing options...
charlieboo Posted March 10, 2007 Author Share Posted March 10, 2007 Checked both intake and exhaust clearances and all are within spec. One of the cam position sensors looks like it's been hit with a hammer on one corner. Double checked that the cam wasn't smashing into it though. Also, I noticed that when turning the crank (by hand) there is a point where there is a lot of resistance. Then is suddenly eases off again. Is this normal? Link to comment Share on other sites More sharing options...
geoffvalenti Posted March 10, 2007 Share Posted March 10, 2007 If it happens 3 times per revolution, its just the engine coming on compression. Link to comment Share on other sites More sharing options...
charlieboo Posted March 11, 2007 Author Share Posted March 11, 2007 Put everything back together today and did a compression check. I get (cylinder 1 to 6) 160, 140, 160, 140, 130, 110 (psi). Does this eliminate valve and piston issues? Link to comment Share on other sites More sharing options...
Kranz Posted March 11, 2007 Share Posted March 11, 2007 Compression figures should ideally be within 5% of each other... so if highest is 160 then lowest should be 152!! Your 110 and to some extent 130 sounds bad Try squirting a teaspoon of oil into the cylinders and do 5 & 6 again exactly the same way you did them before. If pressures come up its the rings. If not its valve problems. Link to comment Share on other sites More sharing options...
Recommended Posts
Please sign in to comment
You will be able to leave a comment after signing in
Sign In Now