Video of 1st 4 minutes of engine running after cold start

[Jonathan]

Here's a 4 minute video I made today of 3937 starting up from cold. I wanted to document how it sounded/looked prior to me getting the exhaust manifold gaskets done later this week. What do you think? The tick-tacking noise changes dramatically at about 2:35. I am guessing this might be due to some kind of thermal expansion unless told otherwise? Car does it just about every time. The tapping type noise is event while driving when you give it gas, but hardly at all when you're coasting. I was kind of happy to see in the video how rock solid my idle RPM's are. I'd love to hear your comments or thoughts on anything else you see going on with my car :)


http://www.youtube.com/watch?v=t2yvgO3lNkE

[Bitsyncmaster]

Funny the clacking stops so suddenly. Maybe that clacking is the exhaust still burning a rich mixture. I know your lambda is not working since your O2 sensor is not mounted. So it may be your WUR suddenly get the mixture close.

[Jonathan]

Funny the clacking stops so suddenly. Maybe that clacking is the exhaust still burning a rich mixture. I know your lambda is not working since your O2 sensor is not mounted. So it may be your WUR suddenly get the mixture close.

Hmmm, how do you mean about the O2 sensor?? I must have missed that part?!?

[DMC5180]

That change is likely the Lambda finally kicking in. According to the Service Manual, The O2 sensor needs to reach approx. 300℃ Before it starts actively controlling. Idle warm up @775 is slow but predictable. 2-3 minutes is normal from stone cold engine. Prior to LAMBDA activating, the system runs at a fixed setting.

[DMC5180]

Funny the clacking stops so suddenly. Maybe that clacking is the exhaust still burning a rich mixture. I know your lambda is not working since your O2 sensor is not mounted. So it may be your WUR suddenly get the mixture close.

Where did you see the O2 sensor not mounted?

[Bitsyncmaster]

Where did you see the O2 sensor not mounted?

I mistook it that his exhaust manifolds were not installed, hence no O2 in the exhaust. Now that I think about it, without those it really would have been loud.

So I would have to agree the lambda kicked the mixture down. So that clacking has to be the rich exhaust.

[Jonathan]

So I would have to agree the lambda kicked the mixture down. So that clacking has to be the rich exhaust.

Ok, at least it got me out looking. I can see the O2 sensor mounted in the exhaust pipe just before it enters the catalytic converter. The wire from it seems to disappear through a small hole in the frame in the general vacinity of the rear left wheel well and behind the drivers seat. I can see the controller behind the seat, but can't figure out where the O2 sensor actually goes to. I'm assuming it's plugged in where it should be at this point (?).

Now the rich exhaust part, is that something that I should be trying to make an adjustment on? Or is all of this going to become a non-issue once the new exhaust manifold gaskets go in?

[DMC5180]

Ok, at least it got me out looking. I can see the O2 sensor mounted in the exhaust pipe just before it enters the catalytic converter. The wire from it seems to disappear through a small hole in the frame in the general vacinity of the rear left wheel well and behind the drivers seat. I can see the controller behind the seat, but can't figure out where the O2 sensor actually goes to. I'm assuming it's plugged in where it should be at this point (?).

Now the rich exhaust part, is that something that I should be trying to make an adjustment on? Or is all of this going to become a non-issue once the new exhaust manifold gaskets go in?

Once you the new exhaust gaskets are in, the major tick-tick will go away. You'll still get some light sound change with the lamba activation. That's normal. Once the exhaust is quieted you may here valve ticking if they have never been adjusted. (Recommend at 60K) but thats a tap-tap sound from the rocker covers.

[Bitsyncmaster]

I'm assuming it's plugged in where it should be at this point (?).

Now the rich exhaust part, is that something that I should be trying to make an adjustment on? Or is all of this going to become a non-issue once the new exhaust manifold gaskets go in?

The O2 wire only has that one connector at the wheel well. It then goes to a blue shielded wire into the lambda ECU connector.

You will want to check your hot engine mixture setting later. That is done with a dwell meter on the FV. That setting does affect the warm up mixture but you can not adjust your warm up mixture unless you "tinker" with the WUR.

[Jonathan]

And here's the after video. My guy did a great job, the car is shockingly quiet now. I also think the garage amplifies the noise a fair bit, but you get the idea.


http://www.youtube.com/watch?v=EPhH_NowHh8

[Bitsyncmaster]

Very nice.

[JIMJAM]

Man that some pipes you have and I do not mean the cars.
You could make a living with that voice. Reminds me of a old video game hero Duke Nukem.

Also the after sound just like mine. A slight hint of a tic that bothered me for years but seems to be normal for these cars. Also a amp reading to kill for.

[Chris Burns]

When I was working with 4980, it did the same thing. My mechanic looked at it and said it had an exhaust leak. Amazing how that fixes the problem.

[Jonathan]

Man that some pipes you have and I do not mean the cars.
You could make a living with that voice. Reminds me of a old video game hero Duke Nukem.

Thanks dude :) Yea, I got the deep one. And would you believe it is my brother and not me that opted for the career in radio?? My voice will have to be content with just doing Christmas Vacation quotes at family get togethers :D