REALLY BAD sound coming from engine at startup - listen to it here.

The horrible knocking just happened to me this last week - the temperature had dropped, and when I tried to start up, there was a terrible knocking, like in the video posted here in the chat by Steve_in_NJ above. I immediately shut off the engine. Waited, and tried to start again. Same thing. On the fourth try, the engine started normally.

It sounds to me like a sticking valve? And I wonder what damage it's doing to the motor mounts? Yikes!

Does it throw any sort of code for the dealer to look at?

This has happened to me in the past, but I didn't think to look here about it. I did mention it to my dealer, and all they said was something like, "Yes, it happens sometimes when it's cold."

 

there's no fix. try not to shut the car down while the engine is running. i thought there was a tsb for replacement intake manifold though.

 

As Bisco stated, don't turn off the engine until it goes into EV. I never shut off the car until it goes into EV.

 

I never put 2 & 2 together to notice that it seems related to what engine cycle it's in at shutdown. I usually drive into the garage and shut down. In winter, the engine may be running, just because of the heater.

Should I ask the dealer to check the engine mounts? When it's done this, it shakes the whole car violently. When the engine is running normally, there's no shaking.

I may go to the dealer anyway, because the rear hatch struts aren't opening the hatch all the way like they used to, and I've banged my head a few times times now, because the hatch wasn't all the way open.

 

You can have the mounts checked, but should be fine. Try allowing the ICE to turn off before shutting down. It should work.

 

Regarding the hatch struts, don't buy from the dealer. You can get replacements that are less than $20/each from Amazon (Strongarm brand) vs hundreds of dollars from the dealer.

I just replaced our hatch struts with shorter ones to keep the spoiler from hitting low ceilings and stuff (opened garage door, pipes in garage structures, etc). But you can replace them with oem comparable struts too.

One of the oem struts gave out, so the hatch wouldn't stay open on its own.

 

Mine made that sound too. Turns out I had a leaking headgasket.

 

interesting, no other symptoms?

 

How did that go? Cost?

 

this time they were right.

interesting, there was a PC member (russian IIRC) who replaced an engine himself due to HG leak that started as knocking. it wasn't you, right?

 

I had a check engine light eventually pop up, P0301, slight buildup of exhaust gases in the coolant reservoir, and coolant usage (about two inches per thousand miles. For reference, it was at 190360. I have coolant samples I saved, I still need to get the correct test strips to check the coolant PH which will determine whether the coolant had gone bad leading to the HG erosion and failure.

Not too bad considering I'd never done anything except small engine repair/rebuild before. Cost came out to about $1300, I used a DIY rental garage with tools, and the HG kit ran me about $200 but got refunded because most of the gaskets in the kit did not fit correctly (FelPro). Car has ~10k miles on it since HG job and is running perfectly aside from the HV battery (1 module failure).

Nope, not me, but I did do the entire HG replacement myself. Need to do the DIY sometime as soon as I finish this semester I will (16 units and finals approaching

 

How many hours did it take you and did you end up having to resurface the head or just replaced the gasket? Which Felpro kit did you buy and what gaskets didn't work out? Odd that it would be that off unless they shipped the wrong set...