Hey guys, I was driving to the city today n half way there the car started doing some strange things... Symptoms: 1. At 3000rpm to 3100rpm with half throttle of more it sounds like there is a muffled cricker sound coming from the engine... Like when its hot n they get goin but really really quiet and muffled.. 2. When i easy of the throttle and there is abit back pressure same sound just abit more quiet again 3. If i open the throttle up fully in say 4th 2000rpm before the criket noise starts i can hear like a ticking noise... which i think has something to do with the exhaust... Sounds abit like the ticking VW Kombis have... 4. If i open full throttle in 5th @ 1000rpm the engine jerks at constant intervals... Sometimes it goes away after a few jerks, other times it keeps going... 5. None of the above happens when the car is in neutral n i rev it nor when its idling... no tapping, ticking or crikets... About 2 weeks ago i put in my 1.95:1 ratio roller rockers so i thought something came loose or dis-aligned... So i opened the engine up again, retorqued them all again n made sure they were properly aligned... They where all in tip top shape, all still tightly torqued and aligned. Also there was no evidence on the rockers, the rocker covers or the metal around the rockers of anything hitting anything... The car is goin into the mechanic this tuesday but i want to try n work out what it could be caus its annoying the cr*p out of me... Ideas of mine: -Something in the exhaust, a loose bit of something in the cat...? -Something wrong with the spark plugs or leads... -I remember i had something similar in my VN noise wise and it was a head gasket or something... but that noise when away once the car warmed up... Any help would be great guys! Regards, Raf
i doubt it would be the cat or exhaust, that would just rattle like crazy under load if it were, and it sounds real "tinny". it could be spark related as you mentioned, but that can be easily ruled out if you've got a multimeter handy - you did put the leads back on the right way round? lol are all these noises in time with the engine? like does it become faster and/or louder with more revs?
No, it doesn't get faster with revs... It happens at about 3000rpm with more that half throttle and then goes away by about 3600rpm... Doesn't really get louder or anything... N they noises aren't there all the time, just under the conditions i listed in the first post
Quick question... Could this be caused by putting too much oil in or mixing oils?!? When i put the rockers in i topped up the oil with some castrol gtx and also i used a different oil on the actual rockers...? Cheers
Its not pinging is it? Sounds like marbles in the engine, and only happens under load? If this is the case you'll need something to clean the carbon out of the engine, i.e. Holden Top Engine Cleaner. Stick it in the fuel and it will give it a good clean. Other then that, is there a tiny exhaus leak on your exhaust manifold? But the noise should still be there at idol.
Dude, i gotta say... i think you might be on the ball... So whats this carbon cleaner stuff?? Where can i get it @ 5pm on a monday?? lol
Also just been reading up on fuels.... Could the fact that i put BP Ultimate in the car cause this since its the first time i've run the car on high octane fuel??
Normally higher octane fuel helps to stop pinging. But hearing that you don't normally run Ultimate or other high octane fuels leads me to think that you probably have a bit of carbon build up. Ultimate, Powermax, Vortex etc are a cleaner burning fuel and some of them have cleaning agents in them to help cleaning. I would suggest using 98 fuel from now on, especially if your modifying your car for extra performance. The best stuff to use is Holden’s Top Engine Cleaner. You should be able to purchase it from your local Holden spare parts for less then $20. To use it run your car low on fuel and carry the top engine cleaner and a pair of pliers in the car. Go to the fuel station and put the top engine cleaner in BEFORE the fuel. You'll need the pliers to open the safety seal on the bottle. You then put 30 litres of fuel in (as per the instructions on the bottle), don't put more fuel in otherwise you will dilute it too much. The T.E.C. goes in first so that it gets mixed with the fuel and you wash the plastic filler neck of your tank. Then drive like normal and try to run the fuel down as low as possible, without running out, to get the most from it. Then its all back to normal. Jezz
Sweet man, thanx.. You've been a big help! PS tried to give u rep for ur hlp but i already did not long ago so it didn't let me...lol
