Why do I hear a low knoking noise?

88_944 · 88_944's Garage

What the hell? When the engine is cold I hear a low knocking noise coming from the oil pan or some where around there but When the engine is at normal temp, it goes away. I just change the oil to 5-30W. Anyone have this dumb prob?

------------------
PORSCHE There is no Substitute!
My 944 Site! http://www.skybusiness.com/dean/

[This message has been edited by 88_944 (edited 08-21-2001).]

3sonfather · 08-21-2001, 04:26 AM

Unless you live on the north pole, I would go with a thicker oil 10w-40 min to 20w-50 max.

mike944 · 08-21-2001, 03:12 PM

change your oil NOW to something thicker, before you destroy your engine!

What you're probably hearing is the crank or the rods clunking around in the bearings, because there is too much clearance with that thin oil in there.

5w30 is for modern cars, with small clearances in their engines. Like 3sonfather said, 10W-40 minimum. Preferably 20w-50 or synthetic 15w-50 I use mobil 1 15W-50

Mike

88_944 · 88_944's Garage

Thanks 3sonfather and mike944!! I just change the oil to 10-40W mobil 1 oil.

------------------
PORSCHE There is no Substitute!
My 944 Site! http://www.skybusiness.com/dean/

T86951 · 08-21-2001, 07:30 PM

I wasn't aware Mobile 1 came in 10w40. 5w30,10w30 and 15w50 are the only ones I have seen.

mike944 · 08-21-2001, 08:05 PM

if you haven't changed it yet, i'd go with 15W-50 Mobil 1. Unless, you live in northern canada.

Mike

88_944 · 88_944's Garage

mike944, the sound is till there but not as bad. When the car is cold, the sound can be heard only alittle while and when the car get warmer the sound goes away. Can you change the con rod bearing just by taking the oil pan out?

------------------
PORSCHE There is no Substitute!
My 944 Site! http://www.skybusiness.com/dean/

mike944 · 08-22-2001, 05:33 PM

I don't know if you can change bearings by just dropping the oil pan. You can on alot of cars, but i'm not sure about the 944.

Dropping the oil pan is not an easy task though!! you have to support the engine from above (hoist of some type) and drop the front suspension crossmember to remove the oil pan. You don't have to drop the crossmember entirely, but you do have to move it down a few inches.

Mike

88_944 · 88_944's Garage

Thanks mike944! Mike you not going to believe what you have to do to take the crank out! It's HELL!! HELL!! HELL!! You have to take out everything for the front to the back and under parts out to get to the crank! Unreal!! I have to get the crank to the shop to fix it and get oversize bearings to. My uncle is going to help me. If I had no help on taking the crank out, I was going to sell this car. No way I was going to do this my self! The parts with polish crank will total cost about $600. Damn!! When I bought this 944 it had a oil and water mixing and that cause this porblem later. Now its knocking and it's the crank bearings or the con rod bearings. A lesson I learn!!

------------------
PORSCHE There is no Substitute!
My 944 Site! http://www.skybusiness.com/dean/

[This message has been edited by 88_944 (edited 08-23-2001).]

mike944 · 08-23-2001, 04:03 PM

you didn't say anything about the oil and water mixing in your first post. That, combined with the knocking noise is a sure sign that your bearings are shot.

Mike

T86951 · 08-23-2001, 08:01 PM

Sorry about your bearing. oil and water mixing will do that to any motors bearings. pulling the engine to rebuild the lower end may be easier.

lordgrommit · 08-23-2001, 09:50 PM

do not use mobile 1 in a high mileage engine unless you want it to leak like a seive. The stuff in it will clean out all the oil passages and the oil that is caked around seals then the damm thing will leak. I've had this happen on a volvo and my 944 just use a good 20W-50 and hope for the best.

Matt