Noises from Engine Top End on Cold Start
#1
Noises from Engine Top End on Cold Start
Does anyone else have a clicking noise from the top end of the engine on cold starts? It persists for a few minutes and is most noticeable at idle. It sounds like injector or lifter noise. I remember discussion about a similar noise in the current generation RX, but don't know if it is the same. I find it very annoying and will take the car in for repair if it doesn't clear up by 500 miles.
#3
Can anything be done to quiet it? It sounds like a lubrication problem. On my old John Deere tractor, I add some Marvel Mystery Oil to the fuel for top-end lubrication. (I know, not advisable on the car.)
#4
fuel pressures are as high as in best diesels, so you get that ticking noise as well.
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#10
#11
Noise explanation
The new 'low friction' engines don't have belts driving the valves anymore. They now have an internal cam chain such as Porsche's have always had. On cold start, you may hear it, but it's not excessive. Does get quieter after engine temps come up. A really good upside is no expensive belt change around 100K. And no adjustments are necessary.
#12
The new 'low friction' engines don't have belts driving the valves anymore. They now have an internal cam chain such as Porsche's have always had. On cold start, you may hear it, but it's not excessive. Does get quieter after engine temps come up. A really good upside is no expensive belt change around 100K. And no adjustments are necessary.
Interesting that I just called my service manager who I've dealt with for the past couple years and asked him about it. He also cited the timing chain, but he's going to research the issue and call me back. I've owned plenty of engines with timing chains and they are silent. Even the Cadillacs are silent while they oil starve the timing chains and stretch them to the point of failure.
Last edited by caddyowner; 04-03-12 at 05:18 AM.
#13
The only thing I can guess by that is GM's engineering dept didn't get it right with the chains. I've driven Porsche 911's and 4 cyl (older version) Honda bikes for decades with never the 1st failure. The Honda's did have a chain tension adjustment which was easy to use.
LOL as a former owner of two GM 3.6 engines which infamously eat timing chains, I can assure you that is not the same noise. Google "CTS timing chain" and learn how GM can screw up a perfectly good idea.
Interesting that I just called my service manager who I've dealt with for the past couple years and asked him about it. He also cited the timing chain, but he's going to research the issue and call me back. I've owned plenty of engines with timing chains and they are silent. Even the Cadillacs are silent while they oil starve the timing chains and stretch them to the point of failure.
Interesting that I just called my service manager who I've dealt with for the past couple years and asked him about it. He also cited the timing chain, but he's going to research the issue and call me back. I've owned plenty of engines with timing chains and they are silent. Even the Cadillacs are silent while they oil starve the timing chains and stretch them to the point of failure.
#15
Instead of normal fuel injected systems that run from 28-50 psi, these run at 750-1800psi.
So they have a very hi-pressure fuel pump up by the fuel rails and 6 high pressure injectors...
As more manufactures invest in the technology, you will see more cars with it, as direct injecting adds power and efficiency.. (MPG)