erictown

2000 MaximaSE with 180k miles.

due to the extreme cold weather a week ago, I notice that a knocking or rattling noise from passenger side of the engine bay. Something like a bad bearing of pulley, or timing chain was hitting the wall. It lasted only a few seconds and then dinimished almost non-noticeable.

this morning I poured 200ml seafoam in to crank case due to my maintenance schedule. It's time to change oil. Just after I started my Max, the previous transient noise became persistent. Not very loud but clearly noticeable like something knocking or metal to metal friction. It does not change with RPM. Another noticeable change was, when I rev engine up to 3500rpm and then release pedal, rpm drops down to 500 like engine choked a bit and then rise up again to normal idle of 900rpm-1000rpm.

what could be the problem? Thanks for any reply

SubwayVQ

Sounds like the timing chain was slapping around. It's "normal" and will not cause issues. Just means your timing chain tensioner can't hold oil pressure all that well. Just put in a 5W-30 synthetic and don't worry about it.

erictown

I was thinking that way too, but if it's from timing chain, won't it change with rpm?

SubwayVQ

No, because as soon as the car builds up full oil pressure, the ticking/knocking goes away. This only takes like 1-2 seconds, max. That's why you only hear it when the car has sat for a long period of time.

erictown

I changed oil tonight, it's still there. I mean the tone of the noise doesn't change with rpm change. It still is the tensioner problem?

erictown

Is it possible to change the tensioner without remove the whole side panel? Cause I see a small window at the tensioner site.

BronxSleeperMax187

If you put some thin cheap oil in there might wanna add something better, I had a clacking noise that I thought was the same thing for two weeks, then instead of being lazy cause of the cold weather I decided to check the oil after the car sat all night.....pull out the dip stick and it had oil on it....wiped it off put it in again...nothing....two quarts of mobil 10-40 synthetic....noise gone for good....hope this helps.

BronxSleeperMax187

Post a video of it so maybe somebody can figure it out here......fan motors makes noise too

SubwayVQ

It goes away right away after the car starts up, correct? If this is the case, it is the tensioner. While mine doesn't make an actual tick, mine makes more of a grinding but it has rattled before. I currently have Pennzoil 5W-30 Synthetic in it and even in 10 degree weather, it still only grinds upon startup and goes away after half a second.

If it immediately goes away, don't worry about it. Yes, if you remove the motor mount and access cover you can replace the tensioner.

erictown

UPDATES:

I took the serpentine belt off and the noise was gone. Checking each pulley and AC compressor pulley didn't pass the test, it makes grinding sound when span.

it turns out the noise is from AC compressor pulley, guess the bearing is toasted.

Now, interesting thing happened:

I checked the model of the compressor, it is CWV618 for our MAX. But, it has a early product and late product(it didn't mention where is the line), using different type of bearing.

MT 2021 for late and MT 2029 for early product.



Does anyone know that a Maxima 2000 SE has the early or late CWV618 compressor? which bearing should I buy? MT2021 or MT2029?

AaronL

iTrader: (1)

I just replaced the compressor bearing on my 2001 Max. I thought it was an "early model" based on something I found online that said 2001s made up until Sept were early model, but it ended up needing the MT2021.

If you pull the clutch and the pulley you'll be able to see what size you need.

FWIW - If I had to do it again I would just buy a new pulley with bearing already pressed in (since I had to pay a shop to press it anyways), something like:
https://www.aliexpress.com/item/auto...989565302.html

BTW The OEM bearing in my 2001 was a 35BD219DUK

Child_uv_KoRn

iTrader: (7)

But then you're getting an el cheapo bearing. There is no winning haha

AaronL

iTrader: (1)

If you have access to a shop that will press the bearing for a reasonable price than that's a good way to go (not the case in Vancouver sadly). Are Santech bearings considered high quality? They are made in China so I would expect they are not as good as OEM.

erictown

Thanks a million! I'm in Vancouver too!