Piston slap

[Rick]

I have a 1990 2.0L sunbird and I beleave I have piston slap.
When the engine is warm and I accelerate or de-accelerate. THe engine knocks badly. I have used the german syntec and it knocks, I have used 10w30 pennzoil and it knocks.
So today I descided to go to Canadian tire and I bought the Motomaster Formula 1 20W-50 and put that in. Now it doesn't knock anymore.
Is my issue with the piston rings? Is my block getting tired and needs a re-build.
Or can I get away with just using a thick oil in the summer? I'm just not sure if this knocking is going to kill my engine sooner and what to do in our **** cold winter's that we see -40 temp, or should I not be worried about it and keep sticking with the german syntec even though it will knock with it?
THanks to who replay

 

[SPITMAN]

You may want to try CTC's Formula 1 Synthetic in 5W-50. I have had success with it in a high milage Dodge 3.0L V6 -- it also has enough flow to get started at -40C. CTC quite often has the 4L jug on for under $20CDN.

 

[RussellA]

You might try something in between the german castrol and your Motomaster 20w50. I'm not familiar with motomaster but I'm guessing it's not a synthetic. I would think you would need something synthetic this winter. Mobil 1 0w40 would run a little thicker than the german castrol and might do the trick. If not that I would see if I could get away with Mobil 1 15W50.

I can't say if your knocking is causing wear, but I personally like to keep everything moving and running as smooth and quiet as possible in any of my cars. I figure noise is caused by impact or vibration and that leads to wear.

 

[Doug Hillary]

Hi,
piston "slap" is a term used to describe the piston rocking on its gudgeon ( wrist ) pin against the bore walls. It could be by design - some new engines have it - it could be from wear
It usually stops as the normal expansion of componentry is complete

Does your car consume lots of oil?

As somebody else suggested M! 15w-50 might be worth a try - it has a pour point of around -50C and would probably be a good year round compromise in your car

We have a "farm hack" Datsun Sunny 1200cc has been on Shell Helix Ultra synthetic 15w-50 for about three years and is quiet. Previously it was on a 10w-40 oil and was quite noisy when cold - with piston slap!
It has done nearly 300000kms and does not use oil

My kids learnt to drive in it and it has been over-revved and under-reved but never under serviced

Regards

 

[Rick]

I don't bleave it consumes alot of oil since my brother was behind my car and he saw a little bit of smoke but I had to redline it for that.
So even though my engine called for 5w30 Recommended. I'll be ok with 20W-50 in the summer and 15W-50 mobil 1 in the winter?

 

[Rick]

O and just to let you know the noise does not stop. It did it all the time even when engine is fully warmed up. In 1990 Gm did not have this problem with the 2.0L engine. There problem was with the head gasket. This I beleve it is do to wear since this has started 1 month ago and doesn't go away. Well it has now since I put in 20W-50

I guess I'll just use that for now and probably ct 5W-50 it's hydrocracked but when it's on sale it's only 20 dollars can or something of that sort.
This realy bugs me because I loved the german juice. **** last winter when it was -40 and I saw peoble trying to start there engines cold It sounded horrible. When I started mine It was like it was already warmed up.

 

[Doug Hillary]

Hi,
Rick - it may be wise to get the noise checked out by a mechanic as it could be an engine bearing or other "major component".
An oil pressure check etc. would be wise

The -40 winter temp requires you to check then use the Handbook oil recomendations for that temp.

Regards

 

[Rick]

Actualy oil pressure is super.
Even higher now with thicker oil.
Before warm idle was at 20psi now with the 20W-50 idle pressure is 30psi and when is motion it's usualy at 60psi. Pressure is very constant.

 

[Rick]

Is there anything else that I can do in the winter as far as oil being able to protect my engine since I can't use a conventional 20w50 oil here.
Also am I damaging my oil pump using 20W-50 in the summer?

 

[MRC01]

quote:

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Originally posted by Rick:
Actualy oil pressure is super.
Even higher now with thicker oil.
Before warm idle was at 20psi now with the 20W-50 idle pressure is 30psi and when is motion it's usualy at 60psi. Pressure is very constant.

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Are you sure more pressure due to thicker oil is a good thing? That higher pressure comes at the price of lower flow volume.