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engine knock on cold start

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engine knock on cold start

Postby 68vert » Fri Mar 10, 2017 10:27 am

When I start up my si in the morning, it knocks for about 30 seconds. Longer when its colder out. At first I was thinking the valves need to adjusted but the knocking eventually goes away. The odometer says about 140k miles but carfax shows otherwise. More like 200k miles. Any theories?
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Re: engine knock on cold start

Postby raffaelli » Fri Mar 10, 2017 4:09 pm

Assuming you have eliminating any sort of timing issue.....

The block is getting old. The knock you are hearing may be a rod or piston with an increased clearance due to wear. As soon as it heats up, the parts expand and close down the clearances, eliminating the knock. Keep after the oil. Change it often, use a good filter.

My DD D16Y7 Civic has had a similar knock for about 100K miles now.
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Re: engine knock on cold start

Postby Mista Bone » Fri Mar 10, 2017 8:06 pm

cold piston slap....let the engine run at cold idle for 30 seconds if above freezing, 60 seconds if below freezing before driving away, being easy on the motor as well.
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Re: engine knock on cold start

Postby crocrx » Fri Mar 10, 2017 11:55 pm

Yep piston slap for sure.
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Re: engine knock on cold start

Postby kracksmith » Sat Mar 11, 2017 2:01 am

could it be a simple valve adjustment?
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Re: engine knock on cold start

Postby Mista Bone » Sat Mar 11, 2017 5:22 pm

kracksmith wrote:could it be a simple valve adjustment?


they would be noisy all the time then.
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Re: engine knock on cold start

Postby 4drSpankR » Sat Mar 11, 2017 10:55 pm

All the above, and possibly a failing oil pump. Developed that same noise, let it warm up every time and then one day just putting around I heard a faint knock, 2-3 miles later it was unmistakable. 5 miles later (had to get to work), it was pretty obvious the motor was done.


Basically, start saving money for what could be an engine job very soon.
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Re: engine knock on cold start

Postby BillyZoom » Sat Mar 11, 2017 11:02 pm

Is it an HF?
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Re: engine knock on cold start

Postby Myriad » Sun Mar 12, 2017 1:53 am

BillyZoom wrote:Is it an HF?


68vert wrote:When I start up my si in the morning,...
I got a new shell, just need to stop driving the DX so I can work on it.

I've got a filter for my mouth, it just isn't a good one.
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